Disassembly of Jupiter ACE ROM
Click here to go to a German text Version [ thanks to Geoff Wearmouth ] ; Disassembly of the file "C:\ACE\JupiterAce.rom" ; ; CPU Type: Z80 ; ; Created with dZ80 1.50 ; ; on Monday, 21 of January 2002 at 07:11 PM ; ; last updated 02-NOV-2002 ; ; Cross-assembles to an 8K ROM file. ; ; Note. A Low-level Assembly Listing only. #define DEFB .BYTE #define DEFW .WORD #define DEFM .TEXT #define EQU .EQU #define ORG .ORG ORG $0000 ; ------------------- ; THE 'START' RESTART ; ------------------- L0000: DI ; disable interrupts. LD HL,$3C00 ; start of 'User' RAM LD A,$FC ; a test byte and 1K masking byte. JR L0028 ; forward to continue at Part 2. ; ------------------- ; THE 'PRINT' RESTART ; ------------------- L0008: EXX ; preserve main registers. BIT 3,(IX+$3E) ; test FLAGS for print destination. JP L03EE ; forward to ; --------------------------- ; THE 'STACK WORD DE' RESTART ; --------------------------- L0010: LD HL,($3C3B) ; SPARE LD (HL),E INC HL JP L085F ; ; ------------------------- ; THE 'POP WORD DE' RESTART ; ------------------------- L0018: LD HL,($3C3B) ; SPARE DEC HL LD D,(HL) JP L0859 ; ; ------------------- ; THE 'ERROR' RESTART ; ------------------- L0020: POP HL LD A,(HL) LD ($3C3D),A ; ERR_NO JP L00AD ; ; ------------------------------------ ; THE 'INITIALIZATION ROUTINE' Part 2. ; ------------------------------------ L0028: INC H ; increase high byte LD (HL),A ; insert A value CP (HL) ; compare to expected JR Z,L0028 ; loop back while RAM is populated. AND H ; limit to nearest 1K segment. LD H,A ; place back in H. LD ($3C18),HL ; set system variable RAMTOP. LD SP,HL ; initialize the stack pointer. ; the Z80 instructions CALL, PUSH and POP can now be used. LD HL,L010D ; prepare to copy the system variables ; initial state from ROM. JR L003B ; skip past the fixed-position restart. ; ----------------------- ; THE 'INTERRUPT' RESTART ; ----------------------- L0038: JP L013A ; jump to somewhere more convenient. ;------------------------------------------------------------------------------ ; ; MEMORY MAP ; ; $0000 +======================================================+ ; | | ; | ROM 8K | ; | v $2300 | ; $2000 +======================================================+ - - - - - - ; | copy of $2400 |0|< cassette >| ; $2400 +-------------------------------------+-+--------------+ ; | VIDEO MEMORY 768 bytes |0| PAD 254 bytes| 1K RAM ; $2800 +-------------------------------------+-+--------------+ ; | copy of $2c00 ^ $2700 | ; $2C00 +------------------------------------------------------+ ; | CHARACTER SET - Write-Only | 1K RAM ; $3000 +------------------------------------------------------+ ; | copy of $3c00 | ; $3400 +------------------------------------------------------+ ; | copy of $3c00 | ; $3800 +------------------------------------------------------+ ; | copy of $3c00 | ; $3C00 +-------+----------------------------------------------+ ; |SYSVARS| DICT {12} DATA STACK -> <- RET STACK | 1K RAM ; $4000 +=======+==============================================+ - - - - - - ; | | ; 48K AVAILABLE FOR EXPANSION. ; | | ; $FFFF +======================================================+ ; ; The Ace had an 8K ROM and was sold with 3K of RAM each byte of which had ; at least two addresses and sometimes four addresses so the mapping of the ; 3K of RAM was as above. ; The 768 bytes of video memory is accessed by the ROM using addresses ; $2400 - $26FF. This gives priority to the video circuitry which also needs ; this information to build the TV picture. The byte at $2700 is set to zero ; so that it is easy for the ROM to detect when it is at the end of the screen. ; The 254 bytes remaining are the PAD - the workspace used by FORTH. ; This same area is used by the tape recorder routines to assemble the tape ; header information but since, for accurate tape timing, the FORTH ROM needs ; priority over the video circuitry, then the ROM uses addresses $2301 - $23FF. ; ; Similarly the Character Set is written to by the ROM (and User) at the 1K ; section starting at $2C00. The video circuitry accesses this using addresses ; $2800 - $2BFF to build the TV picture. It is not possible for the ROM or User ; to read back the information from either address so this precludes the saving ; of character sets and writing a driver for a device like the ZX Printer. ; ; The final 1K or RAM has four addresses although it is normal to use addresses ; $3C00 - $3FFF. The first sixty three bytes are the System Variables which ; hold information like the number BASE and CONTEXT, and even the plotting ; coordinates should the user wish to develop a word like DRAW to draw lines. ; ; Then comes the User Dictionary, the first word of which is "FORTH" which links ; to the Dictionary in ROM. Next a gap of 12 bytes to allow for Data Stack ; underflow and then the Data Stack itself which grows upwards. ; At the opposite end of free memory is the Return Stack (machine stack) which ; grows downwards. ; ------------------------------------ ; THE 'INITIALIZATION ROUTINE' Part 3. ; ------------------------------------ L003B: LD DE,$3C24 ; destination system variable L_HALF LD BC,$002D ; number of bytes. LDIR ; copy initial state from ROM to RAM. LD IX,$3C00 ; set IX to index the system variables. LD IY,L04C8 ; set IY to the SLOW return address. L004B: CALL L0A24 ; routine CLS. XOR A ; clear accumulator. LD ($2700),A ; make location after screen zero. ; There are 128 bit-mapped 8x8 characters. ; Define the 8 Battenberg graphics ($10 to $17) from low byte of address. ; This routine also sets the other characters $00 to $0F and $18 to $1F ; to copies of this range. The inverse form of character $17 is used as the ; normal cursor - character $97. L0052: LD HL,$2C00 ; point to the start of the 1K write- ; only Character Set RAM. L0055: LD A,L ; set A to low byte of address AND $BF ; AND %10111111 RRCA ; rotate RRCA ; three times RRCA ; to test bit 2 JR NC,L005F ; forward if not set. RRCA ; else rotate RRCA ; twice more. L005F: RRCA ; set carry from bit (3) or (6) LD B,A SBC A,A ; $00 or $FF RR B LD B,A SBC A,A XOR B AND $F0 XOR B LD (HL),A ; insert the byte. INC L ; increment low byte of address JR NZ,L0055 ; loop back until the first 256 bytes ; have been filled with 32 repeating ; characters. ; Now copy the bit patterns at the end of this ROM to the last 768 bytes of ; the Character RAM, filling in some blank bytes omitted to save ROM space. ; This process starts at high memory and works downwards. L006E: LD DE,$2FFF ; top of destination. LD HL,L1FFB ; end of copyright character. LD BC,$0008 ; 8 characters LDDR ; copy the © character EX DE,HL ; switch pointers. LD A,$5F ; set character counter to ninety five. ; i.e. %0101 1111 ; bit 5 shows which 32-character sector ; we are in. ; enter a loop for the remaining characters supplying zero bytes as required. L007C: LD C,$07 ; set byte counter to seven. BIT 5,A ; test bit 5 of the counter. JR Z,L0085 ; forward if not in middle section ; which includes "[A-Z]" LD (HL),B ; else insert a zero byte. DEC HL ; decrement the destination address. DEC C ; and the byte counter. L0085: EX DE,HL ; switch pointers. LDDR ; copy the 5 or 6 characters. EX DE,HL ; switch pointers. LD (HL),B ; always insert the blank top byte. DEC HL ; decrement the address. DEC A ; decrement the character counter. JR NZ,L007C ; back for all 95 characters. IM 1 ; Select Interrupt Mode 1 JR L009B ; and then jump into the code for the ; QUIT word. ; --------------- ; THE 'QUIT' WORD ; --------------- ; ( -- ) ; Clears return stack, empties input buffer and returns control to the ; keyboard. L0092: DEFM "QUI" ; 'name field' DEFB 'T' + $80 L0096: DEFW $0000 ; 'link field' - end of linked list. L0098: DEFB $04 ; 'name length field' L0099: DEFW L009B ; 'code field' ; address of machine code for routine. ; --- L009B: LD SP,($3C18) ; set stack-pointer to RAMTOP. EI ; Enable Interrupts. JP L04F2 ; jump forward to the main execution ; loop. ; ---------------- ; THE 'ABORT' WORD ; ---------------- ; Clears the data and return stacks, deletes any incomplete definition ; left in the dictionary, prints 'ERROR' and the byte from address $3C3D ; if the byte is non-negative, empties the input buffer, and returns ; control to the keyboard. L00A3: DEFM "ABOR" ; 'name field' DEFB 'T' + $80 DEFW L0098 ; 'link field' to previous word QUIT. L00AA: DEFB $05 ; 'name length field' L00AB: DEFW L00AD ; 'code field' ; --- ; -> also continuation of the error restart. L00AD: PUSH IY ; preserve current IY value slow/fast. LD IY,L04B9 ; set IY to FAST ; now empty the data stack LD HL,($3C37) ; STKBOT LD ($3C3B),HL ; SPARE LD HL,$3C3E ; address FLAGS LD A,(HL) ; fetch status from FLAGS. AND $B3 ; AND %10110011 ; reset bit 2 - show definition complete ; reset bit 3 - output to screen. ; reset bit 6 - show in interpreter mode BIT 2,(HL) ; was there an incomplete definition ? LD (HL),A ; update FLAGS JR Z,L00DE ; forward if no incomplete word. L00C4: CALL L04B9 ; do forth DEFW L0490 ; dict address of sv DICT DEFW L08B3 ; @ value of sv DICT (d). DEFW L104B ; stk_data d. length field DEFB $05 ; five d, 5. DEFW L0DD2 ; + d+5. code field DEFW L086B ; dup d+5, d+5. DEFW L1610 ; prvcur d+5. DEFW L15B5 ; namefield n. DEFW L1011 ; stackwrd n. DEFW $3C37 ; (stkbot) n, stkbot. DEFW L08C1 ; ! . DEFW L1A0E ; end-forth. . ; at this stage the system variable STKBOT holds the address of the ; obsolete name field and the system variable CURRENT points to the ; address of the previous complete word - obtained from the old link field. L00DE: BIT 7,(IX+$3D) ; test ERR_NO for normal value 255. JR NZ,L00FF ; set-min then main-loop if OK. CALL L1808 ; else pr-inline ; --- L00E7: DEFM "ERRO" ; the message "ERROR" with the last DEFB 'R' + $80 ; character inverted. ; --- L00EC: CALL L04B9 ; forth DEFW L1011 ; stack next word DEFW $3C3D ; -> system variable ERR_NO DEFW L0896 ; C@ - fetch content byte DEFW L09B3 ; . - print it DEFW L0A95 ; CR DEFW L1A0E ; end-forth. LD (IX+$3D),$FF ; set ERR_NO to 'No Error' L00FF: LD HL,($3C37) ; fetch STKBOT LD BC,$000C ; allow twelve bytes for stack underflow ADD HL,BC ; add the extra LD ($3C3B),HL ; set SPARE POP IY ; restore previous state of IY JR L009B ; rejoin main loop ; ------------------------- ; THE 'DEFAULT ENVIRONMENT' ; ------------------------- ; This is the default environment that is copied from ROM to RAM as part of ; the initialization process. This also contains the FORTH word FORTH definition L010D: DEFW $26E0 ; L_HALF DEFB $00 ; KEYCOD DEFB $00 ; KEYCNT copy the 32 bytes. DEFB $00 ; STATIN DEFW $0000 ; EXWRCH DEFB $00 ; FRAMES DEFB $00 ; FRAMES DEFB $00 ; FRAMES DEFB $00 ; FRAMES DEFB $00 ; XCOORD DEFB $00 ; YCOORD DEFW $3C4C ; CURRENT DEFW $3C4C ; CONTEXT DEFW $3C4F ; VOCLNK DEFW $3C51 ; STKBOT DEFW $3C45 ; DICT DEFW $3C5D ; SPARE DEFB $FF ; ERR_NO DEFB $00 ; FLAGS DEFB $0A ; BASE ; FORTH DEFM "FORT" ; The 'name field' DEFB 'H' + $80 ; FORTH DEFW $0000 ; length field - filled when next word ; is defined. DEFW L1FFF ; link field copied to $3C49. DEFB $05 ; name length field DEFW L11B5 ; code field DEFW $3C49 ; address of parameters DEFB $00 ; VOCLNK [$3C4F] DEFB $00 ; - link to next vocabulary. DEFB $00 ; last byte to be copied. to [$3C51] ; ----------------------------------------------- ; THE 'CONTINUATION OF THE Z80 INTERRUPT' ROUTINE ; ----------------------------------------------- ; The destination of the jump at $0038. ; Begin by saving both accumulators and the 3 main registers. L013A: PUSH AF ; preserve both accumulators EX AF,AF' ; PUSH AF ; PUSH BC ; and main registers. PUSH DE ; PUSH HL ; ; Now wait for 62 * 12 clock cycles. ( To avoid flicker perhaps? ). LD B,$3E ; delay counter. L0142: DJNZ L0142 ; self loop for delay ; Increment the 4-byte frames counter for use as a system clock. LD HL,$3C2B ; FRAMES1 L0147: INC (HL) ; increment timer. INC HL ; next significant byte of four. JR Z,L0147 ; loop back if the value wrapped back ; to zero. ; Note. as manual points out, there is no actual check on this and if ; you leave your Ace switched on for 2.75 years it will advance to the ; following system variables although it takes several millennia to advance ; through the screen coordinates. ; Now read the keyboard and if no new key then exit after restoring the ; preserved registers. CALL L0310 ; routine KEYBOARD. LD HL,$3C28 ; address system variable STATIN BIT 0,(HL) ; new key? JR Z,L0176 ; forward if not to RESTORE/EXIT AND A ; zero key code ? JR Z,L0176 ; forward if so to EXIT. CP $20 ; compare to SPACE JR C,L0170 ; forward if less as an Editing Key. BIT 1,(HL) ; CAPS shift? CALL NZ,L0807 ; routine TO_UPPER BIT 2,(HL) ; GRAPHICS mode? JR Z,L0167 ; skip forward if not AND $9F ; convert to one of 8 mosaic characters L0167: BIT 3,(HL) ; INVERSE mode? JR Z,L016D ; forward if not. OR $80 ; set bit 7 to make character inverse. L016D: CALL L0196 ; routine pr_buffer L0170: CALL L01E6 ; routine EDIT_KEY CALL L0282 ; routine pr_cursor ; Before exiting restore the preserved registers. L0176: POP HL ; POP DE ; POP BC ; POP AF ; EX AF,AF' ; POP AF ; EI ; Enable Interrupts RET ; return. ; ----------------------------------- ; THE 'PRINT to LOWER SCREEN' ROUTINE ; ----------------------------------- L017E: CP $0D ; carriage return? JR NZ,L0196 ; forward if not ; a carriage return to input buffer i.e. lower screen memory. LD HL,$2700 ; set pointer to location after the ; input buffer. LD ($3C22),HL ; set ENDBUF - end of logical line LD ($3C20),HL ; set the CURSOR XOR A ; clear A CALL L0198 ; print character zero. LD HL,$26E0 ; left hand position of bottom line. LD ($3C1E),HL ; set INSCRN to this position. RET ; return. ; --------------------------------------- ; THE 'PRINT CHARACTER TO BUFFER' ROUTINE ; --------------------------------------- L0196: AND A ; check for zero character RET Z ; return if so. ; => also called from previous routine only to print a zero skipping above test. L0198: EX AF,AF' ; preserve the output character. LD HL,($3C22) ; fetch ENDBUF end of logical line LD A,(HL) ; fetch character from position AND A ; is it zero ? JR Z,L01A6 ; skip forward if so. ; else lower screen scrolling is required. LD DE,$D900 ; $0000 - $2700 ADD HL,DE ; test if position is within video RAM JR NC,L01CE ; forward if < $26FF ; now check that the limit of 22 lines in lower screen is not exceeded. L01A6: LD DE,($3C24) ; fetch start of buffer from L_HALF LD HL,$DBA0 ; $0000 - $2460 ADD HL,DE ; JR NC,L01E4 ; forward to exit if buffer full. LD HL,($3C1C) ; fetch position SCRPOS for upper screen LD BC,$0020 ; allow an extra 32 characters - 1 line. ADD HL,BC ; SBC HL,DE ; subtract the start of input buffer PUSH DE ; and save the L_HALF value CALL NC,L0421 ; routine to scroll upper display. CALL L02B0 ; find zerobyte loc in HL POP DE ; retrieve the L_HALF value CALL L042F ; routine scroll and blank ; The four system variables INSCRN, CURSOR, ENDBUF and L_HALF are each ; reduced by 32 bytes a screen line. LD HL,$3C1E ; address INSCRN the left-hand location ; of the current input line. LD B,$04 ; four system variables to update L01C9: CALL L0443 ; routine SCR-PTRS DJNZ L01C9 ; repeat for all four pointers. ; ok to print L01CE: CALL L0302 ; routine find characters to EOL. LD D,H ; HL is end of line LD E,L ; transfer to DE register. INC HL ; increment LD ($3C22),HL ; update ENDBUF DEC HL ; decrement DEC HL ; so HL = DE -1 JR Z,L01DD ; skip if BC zero. LDDR ; else move the characters. L01DD: EX AF,AF' ; restore the output character. LD (DE),A ; insert at screen position. ; (a zero if CR lower) INC DE ; next character position LD ($3C20),DE ; update CURSOR L01E4: XOR A ; ? RET ; return. ; ------------------------- ; THE 'EDIT KEY' SUBROUTINE ; ------------------------- L01E6: LD HL,L01F0 ; address the EDIT KEYS table. LD D,$00 ; prepare to index by one byte. LD E,A ; character code to E. ADD HL,DE ; index into the table. LD E,(HL) ; pick up required offset to the ; handling routine. ADD HL,DE ; add to the current address. JP (HL) ; exit via the routine. ; --------------------- ; THE 'EDIT KEYS' TABLE ; --------------------- L01F0: DEFB $20 ; L0210 $00 - RET L01F1: DEFB $13 ; L0204 $01 - LEFT L01F2: DEFB $0C ; L01FE $02 - CAPS L01F3: DEFB $1E ; L0211 $03 - RIGHT L01F4: DEFB $0A ; L01FE $04 - GRAPH L01F5: DEFB $37 ; L022C $05 - DEL L01F6: DEFB $1A ; L0210 $06 - RET L01F7: DEFB $50 ; L0247 $07 - UP L01F8: DEFB $06 ; L01FE $08 - INV L01F9: DEFB $9C ; L0295 $09 - DOWN L01FA: DEFB $C9 ; L02C3 $0A - DEL LINE L01FB: DEFB $15 ; L0210 $0B - RET L01FC: DEFB $14 ; L0210 $0C - RET L01FD: DEFB $D3 ; L02D0 $0D - KEY-ENTER ; ------------------------------- ; THE 'TOGGLE STATUS BIT' ROUTINE ; ------------------------------- ; The keycodes have been cleverly mapped to individual bits of the STATIN ; system variable so this simple routine maintains all three status bits. ; KEY '2' - CAPS SHIFT, '4' - GRAPHICS, '8' - INVERSE VIDEO. L01FE: LD HL,$3C28 ; system variable STATIN XOR (HL) ; toggle the single relevant bit. LD (HL),A ; put back. RET ; return. ; ---------------------------- ; THE 'CURSOR LEFT' SUBROUTINE ; ---------------------------- ; this subroutine moves the cursor to the left unless the character at that ; position is zero. L0204: LD HL,($3C20) ; fetch CURSOR. DEC HL ; decrement value. LD A,(HL) ; fetch character at new position. AND A ; test for zero. (cr) RET Z ; return if so. >> LD ($3C20),HL ; else update CURSOR INC HL ; step back LD (HL),A ; and put character that was at new ; cursor position where cursor is now. L0210: RET ; return. ; Note. various unallocated keys in the EDIT KEYS table point to the ; above RET instruction. ; ----------------------------- ; THE 'CURSOR RIGHT' SUBROUTINE ; ----------------------------- L0211: LD HL,($3C20) ; fetch CURSOR position INC HL ; and increment it. LD DE,($3C22) ; fetch ENDBUF - end of current line. AND A ; prepare to subtract. SBC HL,DE ; test RET Z ; return if zero - CURSOR is at ENDBUF ADD HL,DE ; else reform the pointers. LD ($3C20),HL ; update CURSOR LD A,(HL) ; fetch character at new position. DEC HL ; decrement LD (HL),A ; and insert where cursor was. RET ; ret. ; --------------------------- ; THE 'DELETE CURSOR' ROUTINE ; --------------------------- ; Moves cursor position to right and then continues into DEL-CHAR L0225: LD HL,($3C20) ; fetch CURSOR INC HL ; increment position. LD ($3C20),HL ; update CURSOR ; ------------------------------ ; THE 'DELETE CHARACTER' ROUTINE ; ------------------------------ L022C: CALL L0302 ; routine finds characters to EOL. LD H,D ; transfer CURSOR position DE to HL. LD L,E ; DEC DE ; decrement DE LD A,(DE) ; fetch character to left of original ; cursor. AND A ; test for zero. RET Z ; return if so. >> LD ($3C20),DE ; else update CURSOR LD A,B ; check for count of characters OR C ; being zero JR Z,L023F ; skip if so. L023D: LDIR ; else shift characters to left. L023F: DEC HL ; decrement HL so that points to end - ; last position on the logical line. LD (HL),$20 ; insert a space. LD ($3C22),HL ; set ENDBUF INC C ; reset zero flag?? RET ; return. ; ----------------------- ; THE 'CURSOR UP' ROUTINE ; ----------------------- ; When the cursor is moved up while editing a multi-line word definition, ; then the cursor is first moved to the left of the screen abutting the ; character zeros at the leftmost position. ; These zero characters appear as spaces but mark the beginning of each logical ; line. A logical line may, for instance if it contains a text item, extend over ; several physical screen lines. L0247: CALL L0204 ; routine CURSOR-LEFT JR Z,L0254 ; skip forward if not possible. ; else move left by thirty two positions. This may achieve a vertical move if ; attempted when a word is first being entered. Alternatively if one of the ; calls to cursor left fails having encountered a zero, then all subsequent ; calls will fail. The routine will return with the cursor adjacent to the zero. LD B,$1F ; count 31 decimal L024E: CALL L0204 ; move cursor left thirty one times. DJNZ L024E ; makes thirty two moves counting first RET ; return. ; --- L0254: LD HL,($3C1E) ; fetch INSCRN start of current line. LD DE,($3C24) ; fetch L_HALF start of buffer. AND A ; reset carry for SBC HL,DE ; true subtraction. RET Z ; return if at beginning of input buffer CALL L0225 ; routine DEL-CURSOR LD HL,($3C1E) ; fetch INSCRN leftmost location of ; current line. LD DE,$FFE0 ; make DE minus thirty two. XOR A ; clear accumulator to zero. L0269: ADD HL,DE ; subtract 32 CP (HL) ; compare contents to zero ; ( i.e. prev (cr) or buffer start?) JR NZ,L0269 ; loop back until HL holds zero. LD ($3C1E),HL ; update INSCRN CALL L02F4 ; find endbuf LD ($3C20),HL ; set CURSOR ; ---------- ; PR_CURSOR ; ---------- L0276: LD A,$A0 ; inverse space - so solid square CALL L017E ; routine PR_LOWER LD HL,($3C20) ; CURSOR DEC HL LD ($3C20),HL ; CURSOR ; -> from interrupt L0282: LD HL,($3C20) ; CURSOR LD A,($3C28) ; STATIN RRA ; ignore bit 0 LD (HL),$97 ; pixel cursor. RRA ; test bit 1 - CAPS JR NC,L0290 ; forward if no CAPS SHIFT LD (HL),$C3 ; inverse [C] cursor. L0290: RRA ; test bit 2 - GRAPHICS. RET NC ; return if not L0292: LD (HL),$C7 ; inverse [G] cursor. RET ; return ; ------------------------- ; THE 'CURSOR DOWN' ROUTINE ; ------------------------- L0295: CALL L0211 ; routine CURSOR RIGHT JR Z,L02A2 ; forward if not possible. LD B,$1F ; set counter to thirty one. L029C: CALL L0211 ; routine CURSOR RIGHT DJNZ L029C ; thirty two moves altogether. RET ; return. ; --- L02A2: CALL L02B0 ; find zerobyte RET PO ; return if found PUSH HL ; save position CALL L0225 ; routine DEL-CURSOR POP HL ; retrieve position. CALL L02ED ; set logical line JR L0276 ; back to exit via pr_cursor. ; --- ; find zerobyte ; --- ; -> called 5 times L02B0: LD HL,$2700 ; this location is always zero. ; the byte following video RAM. LD DE,($3C1E) ; INSCRN e.g. $26E0 AND A ; prepare for true subtraction SBC HL,DE ; subtract to give number of chars LD B,H ; transfer count to LD C,L ; the BC register pair. EX DE,HL ; transfer INSCR value to HL. INC HL ; start next location XOR A ; search for a zero character. CPIR ; at most BC locations. ; sets P/O flag if BC!=0 DEC HL ; step back to last non-zero RET ; return. ; ------------------------- ; THE 'DELETE LINE' ROUTINE ; ------------------------- ; CHR$ 10 L02C3: LD HL,($3C22) ; ENDBUF DEC HL ; LD ($3C20),HL ; CURSOR L02CA: CALL L022C ; KEY-DEL JR NZ,L02CA ; repeat RET ; return. ; -------------------------- ; THE 'KEY-ENTER' SUBROUTINE ; -------------------------- L02D0: LD HL,$3C28 ; STATIN SET 5,(HL) ; signal new key. RES 0,(HL) ; reset new key flag RET ; return. ; ------------------------ ; THE 'SET BUFFER' ROUTINE ; ------------------------ ; called by LIST, QUERY L02D8: LD HL,$2700 ; one past end of screen. LD DE,($3C24) ; fetch start of buffer from L_HALF CALL L07FA ; routine SPACE_FILL LD HL,$26E0 ; first location of bottom line. LD ($3C24),HL ; set L_HALF LD (HL),$00 ; insert a ZERO. ; -> called by retype L02EA: LD HL,($3C24) ; fetch L_HALF ; -> from cursor down L02ED: LD ($3C1E),HL ; set INSCRN INC HL ; step past the zero LD ($3C20),HL ; set CURSOR ; => from cursor up. L02F4: CALL L02B0 ; find zerobyte LD A,$20 ; prepare a space L02F9: DEC HL ; move to the left. CP (HL) ; compare to space. JR Z,L02F9 ; back while spaces exist. INC HL ; point to last space encountered. LD ($3C22),HL ; set ENDBUF - end of logical line. RET ; return. ; ---------------------------------- ; THE 'COUNT TO END OF LINE' ROUTINE ; ---------------------------------- ; Find the number of characters to the end of the logical line. L0302: LD HL,($3C22) ; system variable ENDBUF LD DE,($3C20) ; system variable CURSOR AND A ; prepare to subtract. SBC HL,DE ; subtract to give character places LD B,H ; transfer result LD C,L ; to the BC register pair. ADD HL,DE ; reform the pointers. RET ; return with zero flag set if cursor ; at EOL. ; ---------------------- ; THE 'KEYBOARD' ROUTINE ; ---------------------- L0310: CALL L0336 ; routine KEY_SCAN LD B,A ; save key in B LD HL,($3C26) ; load L with KEYCOD - last key pressed ; load H with KEYCNT - debounce counter XOR L ; compare to previous key. JR Z,L0325 ; forward if a match. XOR L ; reform original JR Z,L0320 ; forward if zero - no key. XOR A ; else clear accumulator. CP L ; compare with last. RET NZ ; return if not zero. L0320: LD L,B ; set L to original keycode LD H,$20 ; set counter to thirty two. JR L0332 ; forward to store values and exit ; returning zero. ; --- ; Key is same as previously accepted key. ; It repeats after two interrupts L0325: DEC H ; decrement the counter. LD A,H ; fetch counter to A. CP $1E ; compare to thirty. JR Z,L0331 ; forward if so to return key in A. XOR A ; clear accumulator. CP H ; is counter zero? JR NZ,L0332 ; forward if not to keep counting. LD H,$04 ; else set counter to four. L0331: LD A,L ; pick up previous key. L0332: LD ($3C26),HL ; update KEYCOD/KEYCNT RET ; return. ;---------------------------------------------------------------------------- ; LOGICAL VIEW OF KEYBOARD ; ; 0 1 2 3 4 -Bits- 4 3 2 1 0 ; PORT PORT ; ; F7FE [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] | [ 6 ] [ 7 ] [ 8 ] [ 9 ] [ 0 ] EFFE ; ^ | v ; FBFE [ Q ] [ W ] [ E ] [ R ] [ T ] | [ Y ] [ U ] [ I ] [ O ] [ P ] DFFE ; ^ | v ; FDFE [ A ] [ S ] [ D ] [ F ] [ G ] | [ H ] [ J ] [ K ] [ L ] [ ENT ] BFFE ; ^ | v ; FEFE [SHI] [SYM] [ Z ] [ X ] [ C ] | [ V ] [ B ] [ N ] [ M ] [ SPC ] 7FFE ; ^ v ^ v ; Start +------------>--------------------->-------------+ End ; ; ;---------------------------------------------------------------------------- ; ---------------------------------- ; THE 'KEYBOARD SCANNING' SUBROUTINE ; ---------------------------------- ; This routine is called by the KEYBOARD routine 50 times a second and ; by the ACE FORTH 'INKEY' WORD. ; The above diagram shows the logical view of the Keyboard and PORTS. ; The physical view is similar except that the symbol shift key is to the ; left of the space key. L0336: LD BC,$FEFE ; port address - B is also an 8 counter IN D,(C) ; read from port to D. ; when a key is pressed, the ; corresponding bit is reset. LD E,D ; save in E SRL D ; read the outer SHIFT key. SBC A,A ; $00 if SHIFT else $FF. AND $D8 ; $00 if SHIFT else $D8. SRL D ; read the symbol shift bit JR C,L0347 ; skip if not pressed. LD A,$28 ; load A with 40 decimal. L0347: ADD A,$57 ; gives $7F SYM, $57 SHIFT, or $2F ; Since 8 will be subtracted from the initial key value there are three ; distinct ranges 0 - 39, 40 - 79, 80 - 119. LD L,A ; save key range value in L LD A,E ; fetch the original port reading. OR $03 ; cancel the two shift bits. LD E,$FF ; set a flag to detect multiple keys. ; KEY_LINE the half-row loop. L034F: CPL ; complement bits AND $1F ; mask off the rightmost five key bits. LD D,A ; save a copy in D. JR Z,L0362 ; forward if no keys pressed to do the ; next row. LD A,L ; else fetch the key value INC E ; test E for $FF JR NZ,L036B ; forward if not now zero to quit L0359: SUB $08 ; subtract 8 from key value SRL D ; test next bit affecting zero and carry JR NC,L0359 ; loop back until the set bit is found. LD E,A ; transfer key value to E. JR NZ,L036B ; forward to abort if more than one key ; is pressed in the row. L0362: DEC L ; decrement the key value for next row. RLC B ; rotate the 8 counter and port address JR NC,L036D ; skip forward when all 8 rows have ; been read. IN A,(C) ; else read the next half-row. JR L034F ; and back to KEY_LINE. ; --- ; ABORTKEY L036B: LD E,$FF ; signal invalid key. ; the normal exit checks if E holds a key and not $FF. L036D: LD A,E ; fetch possible key value. INC A ; increment RET Z ; return if was $FF as original. LD HL,L0376 ; else address KEY TABLE ADD HL,DE ; index into table. ; (D is zero) LD A,(HL) ; pick up character. RET ; return with translated character. ; --------------- ; THE 'KEY TABLE' ; --------------- ; ----------------------- ; THE '40 UNSHIFTED KEYS' ; ----------------------- L0376: DEFB $76 ; V - v DEFB $68 ; H - h DEFB $79 ; Y - y DEFB $36 ; 6 - 6 DEFB $35 ; 5 - 5 DEFB $74 ; T - t DEFB $67 ; G - g DEFB $63 ; C - c DEFB $62 ; B - b DEFB $6A ; J - j DEFB $75 ; U - u DEFB $37 ; 7 - 7 DEFB $34 ; 4 - 4 DEFB $72 ; R - r DEFB $66 ; F - f DEFB $78 ; X - x DEFB $6E ; N - n DEFB $6B ; K - k DEFB $69 ; I - i DEFB $38 ; 8 - 8 DEFB $33 ; 3 - 3 DEFB $65 ; E - e DEFB $64 ; D - d DEFB $7A ; Z - z DEFB $6D ; M - m DEFB $6C ; L - l DEFB $6F ; O - o DEFB $39 ; 9 - 9 DEFB $32 ; 2 - 2 DEFB $77 ; W - w DEFB $73 ; S - s DEFB $00 ; SYMBOL DEFB $20 ; SPACE DEFB $0D ; ENTER DEFB $70 ; P - p DEFB $30 ; 0 - 0 DEFB $31 ; 1 - 1 DEFB $71 ; Q - q DEFB $61 ; A - a DEFB $00 ; SHIFT ; --------------------- ; THE '40 SHIFTED KEYS' ; --------------------- DEFB $56 ; V - V DEFB $48 ; H - H DEFB $59 ; Y - Y DEFB $07 ; 6 - 7 KEY-UP DEFB $01 ; 5 - 1 KEY-LEFT DEFB $54 ; DEFB $47 DEFB $43 DEFB $42 DEFB $4A DEFB $55 DEFB $09 ; 7 - 9 KEY-DOWN DEFB $08 ; 4 - 8 INV-VIDEO DEFB $52 DEFB $46 DEFB $58 DEFB $4E DEFB $4B DEFB $49 DEFB $03 ; 8 - 3 KEY-RIGHT DEFB $33 ; 3 - 3 DEFB $45 DEFB $44 DEFB $5A DEFB $4D DEFB $4C DEFB $4F DEFB $04 ; 9 - 4 GRAPH DEFB $02 ; 2 - 2 CAPS LOCK DEFB $57 ; W - W DEFB $53 ; S - S DEFB $00 ; SYMB DEFB $20 ; SPACE DEFB $0D ; ENTER DEFB $50 ; P - P DEFB $05 ; 0 - 5 DEL DEFB $0A ; 1 - 0A DEL_LINE DEFB $51 ; Q - Q DEFB $41 ; A - A DEFB $00 ; SHIFT ; -------------------------- ; THE '40 SYMBOL SHIFT KEYS' ; -------------------------- DEFB $2F ; V - / DEFB $5E ; H - ^ DEFB $5B ; Y - [ DEFB $26 ; 6 - & DEFB $25 ; 5 - % DEFB $3E ; T - > DEFB $7D ; DEFB $3F DEFB $2A DEFB $2D DEFB $5D DEFB $27 DEFB $24 DEFB $3C DEFB $7B DEFB $60 DEFB $2C DEFB $2B DEFB $7F DEFB $28 DEFB $23 DEFB $45 DEFB $5C DEFB $3A DEFB $2E DEFB $3D DEFB $3B DEFB $29 DEFB $40 ; 2 - @ DEFB $57 ; W - W DEFB $7C ; S DEFB $00 ; SYMB DEFB $20 ; SPACE DEFB $0D ; ENTER DEFB $22 ; P - " DEFB $5F ; 0 - _ DEFB $21 ; 1 - ! DEFB $51 ; Q - Q DEFB $7E ; A - ~ DEFB $00 ; SHIFT ; end of key tables ; --------------------------- ; THE 'PRINT ROUTINE' Part 2. ; --------------------------- ; If output is not directed into the input buffer then jump forward else ; call the routine to output to lower screen. L03EE: JR Z,L03F5 ; forward to main screen print. CALL L017E ; PR_LOWER EXX ; restore main set RET ; return. >> ; the print output is not directed to the input buffer but first check that ; the user has not set up a vector to their own routine to print characters ; for instance to a printer. L03F5: LD B,A ; save the character in the B register. LD HL,($3C29) ; fetch possible vector from EXWRCH ; (normally 0) LD A,H ; test for OR L ; the value zero. LD A,B ; fetch the character back to A. JR Z,L03FF ; skip forward if no user-supplied ; routine. L03FE: JP (HL) ; else jump to user-supplied routine ; which should finish with a JP (IY)** ; ** 2022 update This is an error in the ; listing ** ; The character is provided in the A register ; of the Z80. ; The output routine should preserve the ; auxiliary registers, ix and iy, and ; finish off with exx and ret. ; see page 142 of manual. ; --- ; PRINTING TO UPPER SCREEN ; --- L03FF: LD HL,($3C1C) ; SCRPOS LD DE,($3C24) ; L_HALF EX DE,HL ; ?? SCF ; inclusive byte. SBC HL,DE ; subtract screen position+1 from ; the start of input buffer. EX DE,HL ; hl=scrpos CALL C,L0421 ; if no room then scroll upper display CP $0D ; carriage return? JR Z,L0416 ; skip forward if so. LD (HL),A ; else insert the character. INC HL ; point to next position. JR L041C ; forward ; --- ; a carriage return L0416: INC HL ; increment screen address. LD A,L ; fetch low byte of address and mask. AND $1F ; a zero result indicates a line skip. JR NZ,L0416 ; loop until a new line of 32 columns ; is started. ; both paths converge. L041C: LD ($3C1C),HL ; update SCRPOS EXX ; back to main set. RET ; return. ; ------------------------------------- ; The 'UPPER DISPLAY SCROLLING' ROUTINE ; ------------------------------------- L0421: PUSH AF ; save character LD HL,$3C1C ; address the low order byte SCRPOS CALL L0443 ; routine cursor up ; i.e. SCRPOS = SCRPOS - 32 POP AF ; restore character ; now calculate the number of characters to scroll in the upper display. LD HL,($3C24) ; fetch L_HALF the start of input buffer LD DE,$2420 ; second line in video display ; ; => scroll lower display enters here L042F: AND A ; prepare for true subtraction. SBC HL,DE ; find number of characters to scroll. LD B,H ; result to BC LD C,L LD HL,$FFE0 ; set HL to -32d ADD HL,DE ; now HL = DE -32d EX DE,HL ; switch so DE = HL - 32 LDIR ; scroll the lines up. LD B,$20 ; blank a line of 32 characters L043D: DEC HL ; decrement screen address. LD (HL),$20 ; insert a space character DJNZ L043D ; and loop for all 32 characters RET ; return. ; -------------------------------- ; THE 'SCREEN POINTERS' SUBROUTINE ; -------------------------------- ; L0443: LD A,(HL) ; fetch low byte of screen address SUB $20 ; subtract thirty two characters. LD (HL),A ; and put back. INC HL ; address high-order byte. JR NC,L044B ; forward if low byte did not wrap DEC (HL) ; else decrement the high byte as the ; position has moved across a third of ; the display. L044B: INC HL ; address following System Variable RET ; return. ; ----------------------------------- ; THE 'INDEX SYSTEM VARIABLE' ROUTINE ; ----------------------------------- ; This routine is used by words CONTEXT, CURRENT, BASE etc. to index and then ; stack a system variable associated with a FORTH word. See shortly. ; ; It is a bit overblown considering the eventual position of the System ; Variables and ld d,$3c; rst 10h; jp (iy) could have been used instead of ; the long-winded addition below. L044D: EX DE,HL ; HL addresses the offset byte. LD E,(HL) ; fetch to E register ; LD D,$00 ; prepare to add. LD HL,$3C00 ; the address of start of SYSVARS ADD HL,DE ; add the 8-bit offset EX DE,HL ; location to DE. RST 10H ; push word DE JP (IY) ; to 'next'. ; --------------- ; THE 'HERE' WORD ; --------------- ; ( -- address) ; Leaves the address of one past the end of the dictionary. L0459: DEFM "HER" ; 'name field' DEFB 'E' + $80 DEFW L00AA ; 'link field' L045F: DEFB $04 ; 'name length field' L0460: DEFW L0462 ; 'code field' ; --- L0462: LD DE,($3C37) ; system variable STKBOT. RST 10H ; push word DE JP (IY) ; to 'next'. ; ------------------ ; THE 'CONTEXT' WORD ; ------------------ ; ( -- 15411 ) ; A system variable pointing to the context vocabulary. ; $3C33 CONTEXT L0469: DEFM "CONTEX" ; 'name field' DEFB 'T' + $80 DEFW L045F ; 'link field' L0472: DEFB $07 ; 'name length field' L0473: DEFW L044D ; 'code field' ; --- L0475: DEFB $33 ; low byte of system variable. ; ------------------ ; THE 'CURRENT' WORD ; ------------------ ; ( -- 15409 ) ; A system variable pointing to the current vocabulary. ; $3C31 CURRENT L0476: DEFM "CURREN" ; 'name field' DEFB 'T' + $80 DEFW L0472 ; 'link field' L047F: DEFB $07 ; 'name length field' L0480: DEFW L044D ; 'code field' ; --- L0482: DEFB $31 ; a single parameter low-byte of $3C31. ; --------------- ; THE 'BASE' WORD ; --------------- ; ( -- 15423) ; A one-byte variable containing the system number base. ; $3C3F BASE L0483: DEFM "BAS" ; 'name field' DEFB 'E' + $80 DEFW L047F ; 'link field' L0489: DEFB $04 ; 'name length field' L048A: DEFW L044D ; 'code field' ; --- L048C: DEFB $3F ; low-byte of system variable BASE ; --- ; These two Internal Words are used to stack the value of FLAGS and DICT. ; ------------------------- ; The 'flags' Internal Word ; ------------------------- L048D: DEFW L044D ; headerless 'code field' ; --- L048F: DEFB $3E ; low-order byte of FLAGS $3C3E ; ------------------------- ; The 'dict' Internal Word ; ------------------------- L0490: DEFW L044D ; headerless 'code field' ; --- L0492: DEFB $39 ; low-order byte of DICT $3C39 ; -------------- ; THE 'PAD' WORD ; -------------- ; ( -- 9985 ) ; Stacks the address of the 254-byte workpad. ; On most FORTH systems the PAD floats about in memory but on the Ace it is ; fixed in location and size. Its definition is simply a constant. l0493 DEFM "PA" ; 'name field' DEFB 'D' + $80 DEFW L0489 ; 'link field' L0498: DEFB $03 ; 'name length field' L0499: DEFW L0FF5 ; 'code field' - stack word ; --- L049B: DEFW $2701 ; parameter is 9985 decimal - ; work pad address ; ------------ ; THE ';' WORD ; ------------ ; Terminates colon, DEFINER and COMPILER definitions. L049D: DEFB ';' + $80 ; 'name field' DEFW L0498 ; 'link field' L04A0: DEFB $41 ; length 1 + $40 (immediate word) L04A1: DEFW L1108 ; 'code field' - compile ; --- L04A3: DEFW L04B6 ; exit L04A5: DEFW L12D8 ; check-for DEFB $0A ; ten marker byte? DEFW L1A0E ; end-forth. ; code gels L04AA: LD HL,$3C3E ; address FLAGS LD A,(HL) ; fetch FLAGS value. AND $BB ; AND %10111011 ; reset bit 2 - show definition complete ; reset bit 6 - show in interpreter mode LD (HL),A ; update FLAGS value. JP (IY) ; to 'next'. ; ---- ; Note. these backward links to the beginning of words will probably be less ; of a mystery when the syntax checking and listing modules are more fully ; explored. A value of $FFFF sometimes occurs. x04b3 DEFB $00 ;; x04b4 DEFB $E8 ;; x04b5 DEFB $FF ;; 04b5 + ffe8 = 049d = ';' ; ---------------------------------- ; THE 'ADDRESS' INTERPRETER ROUTINES ; ---------------------------------- ; ------------------------ ; The 'Exit' Internal Word ; ------------------------ ; Drops the 'Next Word' pointer from the Return Stack thereby ending a ; subroutine and returning to next word in calling thread. L04B6: DEFW L04B8 ; headerless 'code field' ; --- L04B8: POP HL ; discard the next word pointer. ; ------------------------------ ; THE 'ADDRESS INTERPRETER' LOOP ; ------------------------------ ; Sometimes known as the Sequencer. ; ; iy_fast L04B9: POP HL ; word pointer. ; =====> from DOCOLON and BRANCH L04BA: LD E,(HL) INC HL LD D,(HL) INC HL PUSH HL ; word pointer. ; ==> ; L04BF: EX DE,HL LD E,(HL) INC HL LD D,(HL) INC HL EX DE,HL JP (HL) ; jump to machine code (4 clock cycles) ; which will terminate with a JP (IY) ; instruction (8 clock cycles). ; -------------------------------- ; The 'Memory Check' Internal Word ; -------------------------------- ; This internal word which also checks the BREAK key is only used from the ; start of the LINE definition. However the machine code entry point is the ; normal value of the IY register and so this code is executed at the end of ; every word. L04C6: DEFW L04C8 ; headerless 'code field' ; iy_slow L04C8: LD BC,$000B ; allow overhead of eleven bytes LD DE,($3C3B) ; SPARE LD HL,($3C37) ; STKBOT ADD HL,BC ; add the overhead SBC HL,DE ; subtract the SPARE value JR C,L04D9 ; forward if the original 12 byte gap ; remains. ; else stack underflow has occurred. L04D7: RST 20H ; Error 2 DEFB $02 ; Data stack underflow. ; --- L04D9: LD BC,$0000 ; allow no overhead. CALL L0F8C ; check free memory CALL L04E4 ; check BREAK key. JR L04B9 ; back to iy_fast ; ------------------------------------ ; THE 'CHECK FOR BREAK KEY' SUBROUTINE ; ------------------------------------ ; Check for the key combination SHIFT/SPACE. L04E4: LD A,$FE ; read port $FEFE - IN A,($FE) ; keys SPACE, SYMSHIFT, M, N, B. RRA ; test bit for outermost key RET C ; return if not pressed. LD A,$7F ; read port $7FFE - IN A,($FE) ; keys SHIFT, Z, X, C, V. RRA ; test bit for outermost key RET C ; return if not pressed. L04F0: RST 20H ; Error 3. DEFB $03 ; BREAK pressed. ; ------------------------- ; THE 'MAIN EXECUTION' LOOP ; ------------------------- ; The final part of the QUIT definition, as in all FORTH implementations, ; just loops through two FORTH words. ; The first call - to the Address Interpreter - does not return. ; The return address is the next word QUERY which the interpreter pops off ; the Return Stack and then before executing puts the address of the next word ; on Return Stack. The default action of the Address Interpreter is to execute ; words in turn until some word, such as branch, alters this default behaviour. L04F2: CALL L04B9 ; forth. L04F5: DEFW L058C ; QUERY - input buffer DEFW L0506 ; LINE - interpret buffer DEFW L0536 ; prOK - print OK DEFW L1276 ; branch - relative jump L04FD: DEFW $FFF7 ; back to L04F5 ; --- ; the first high-level interpreted word. ; --- ; --------------- ; THE 'LINE' WORD ; --------------- ; Interprets input buffer as a normal FORTH line. L04FF: DEFM "LIN" ; 'name field' DEFB 'E' + $80 DEFW L04A0 ; 'link field' L0505: DEFB $04 ; 'name length field' L0506: DEFW L0EC3 ; 'code field' - docolon ; --- L0508: DEFW L04C6 ; check mem each time through loop ; as dictionary could be expanding. DEFW L063D ; FIND - search the dictionary DEFW L08EE ; ?DUP - duplicate if found DEFW L1283 ; ?branch - forward if not a L0510: DEFW $0007 ; to L0518 - word. DEFW L054F ; test and stack?? DEFW L1276 ; branch L0516: DEFW $FFF1 ; back to L0508 L0518: DEFW L06A9 ; NUMBER DEFW L08EE ; ?DUP DEFW L1283 ; ?branch - forward if not a L051E: DEFW $0007 ; to L0526 - number. DEFW L0564 ; pop de with test DEFW L1276 ; branch L0524: DEFW $FFE3 ; loop back to L0508 L0526: DEFW L061B ; stack-length DEFW L0C1A ; 0= DEFW L1283 ; ?branch - forward with anything L052C: DEFW $0003 ; to L0530 - else L052E: DEFW L04B6 ; EXIT >>> ; --- L0530: DEFW L0578 ; RETYPE - [?] at relevant place DEFW L1276 ; branch - once corrected back L0534: DEFW $FFD3 ; to L0508 - to the loop. ; ---------------------------- ; The 'Print OK' Internal Word ; ---------------------------- ; prints the OK message after successful execution. L0536: DEFW L0538 ; headerless 'code field' L0538: LD A,($3C3E) ; fetch system variable FLAGS BIT 6,A ; test for 'COMPILER' mode. JR NZ,L054D ; forward if so. BIT 4,A ; test for 'INVIS' mode. JR NZ,L054D ; forward if so. CALL L1808 ; else print the inline string. ; --- DEFM " OK" ; the OK message between two spaces. DEFB ' ' + $80 ; last one inverted. ; --- L054A: LD A,$0D ; prepare a carriage return. RST 08H ; and PRINT also. L054D: JP (IY) ; to 'next'. ; ------------------------------ ; The 'XXXXXXXXXX' Internal Word ; ------------------------------ ; to handle a Word from LINE L054F: DEFW L0551 ; headerless 'code field' ; --- L0551: RST 18H ; pop address from Data Stack to DE DEC DE ; point to the 'name length field' LD A,(DE) ; fetch contents of the address. CPL ; complement. AND (IX+$3E) ; FLAGS AND $40 ; isolate BIT 6 of FLAGS, set if in ; compiler mode. INC DE ; increment address to 'code field' JR Z,L0561 ; forward if not in compiling mode RST 10H ; push word DE - add to dict LD DE,L0F4E ; ',' - enclose L0561: JP L04BF ; next word. ; ----------------------- ; The '???' Internal Word ; ----------------------- ; after handling a number from LINE L0564: DEFW L0566 ; headerless 'code field' ; --- L0566: RST 18H ; pop word DE BIT 6,(IX+$3E) ; test FLAGS - compiler mode ? JR NZ,L0561 ; loop back while in compiler mode. JP (IY) ; to 'next'. ; ----------------- ; THE 'RETYPE' WORD ; ----------------- ; Allows user to edit the input line. Turns cursor to [?]. L056F: DEFM "RETYP" ; 'name field' DEFB 'E' + $80 DEFW L058B ; 'link field' L0577: DEFB $06 ; 'name length field' L0578: DEFW L057A ; 'code field' ; --- L057A: CALL L02EA ; routine sets logical line. CALL L0276 ; routine pr_cursor LD (HL),$BF ; the inverse [?] character JR L0594 ; forward to join the QUERY routine. ; ---------------- ; THE 'QUERY' WORD ; ---------------- ; Clears input buffer, then accepts characters until ENTER pressed. ; Buffer can be edited as usual and is limited to 22 lines. L0584: DEFM "QUER" ; 'name field' DEFB 'Y' + $80 DEFW L0505 ; 'link field' L058B: DEFB $05 ; 'name length field' L058C: DEFW L058E ; 'code field' ; --- L058E: CALL L02D8 ; routine SETBUF CALL L0276 ; routine pr_cursor ; -> L0594: LD HL,$3C28 ; fetch STATIN SET 0,(HL) ; RES 5,(HL) ; (bit 5 set by interrupt when the user ; presses the ENTER key) L059B: BIT 5,(HL) ; wait for interrupt to set the bit. JR Z,L059B ; loop until. CALL L0225 ; routine DEL-CURSOR JP (IY) ; to 'next'. ; --------------- ; THE 'WORD' WORD ; --------------- ; WORD text ; ( delimiter -- address ) ; Takes text out of the input buffer up as far as a delimiter, and copies it ; to pad, starting at the second byte there. Puts the length (not including ; the delimiter) in the first byte of the pad, and stacks the address of the ; first byte of the pad. ; At most 253 characters are taken from the input buffer. If there are more ; left before the delimiter, then the first byte of the pad shows 254. ; Initial delimiters are ignored. L05A4: DEFM "WOR" ; 'name field' DEFB 'D' + $80 DEFW L0577 ; 'link field' L05AA: DEFB $04 ; 'name length field' L05AB: DEFW L05AD ; 'code field' ; --- L05AD: RST 18H ; pop word DE LD HL,$27FE ; set HL to penultimate byte of 'pad'. LD B,$FD ; the count is 253. L05B3: LD (HL),$20 ; insert a space in pad. DEC HL ; decrement the address. DJNZ L05B3 ; repeat for the 253 locations. PUSH DE ; save the delimiter. EX DE,HL ; save in HL also, DE is start of pad. RST 10H ; stack data word DE POP DE ; retrieve the delimiter. CALL L05E1 ; INC B DEC B JR Z,L05C6 ; LD BC,$00FF L05C6: LD HL,$2701 LD (HL),C INC HL LD A,$FC CP C JR NC,L05D1 ; LD C,A L05D1: INC C PUSH DE PUSH BC EX DE,HL LDIR POP BC POP DE DEC C CALL L07DA ; JP (IY) ; to 'next'. ; -------------------------------- ; THE 'GET BUFFER TEXT' SUBROUTINE ; -------------------------------- ; Called from FIND, NUMBER and XXXXX. Word may have leading spaces and is ; terminated by a space or newline (zero). ; It is also used to find the end of a comment delimited by ')'. ; ; => L05DF: LD E,$20 ; set a space as the skip character. ; =>called with E holding delimiter. ; L05E1: LD HL,($3C24) ; fetch L_HALF - start of screen buffer. LD ($3C1E),HL ; make INSCRN start of logical line the ; same. LD BC,$0000 ; initialize letter count to zero. ; -> loop L05EA: INC HL ; increment screen address. LD A,(HL) ; fetch character to A. CP E ; compare to character in E. JR Z,L05EA ; loop while character matches. AND A ; test for zero (at $2700?) JR Z,L0600 ; forward if so. ; a word has been found on the screen line. PUSH HL ; save pointer to start of word. L05F3: INC BC ; increment the letter count. INC HL ; increment the screen pointer. LD A,(HL) ; fetch new character AND A ; test for zero. JR Z,L05FC ; skip forward as at end of word. CP E ; compare to the skip character. JR NZ,L05F3 ; loop back if still within a word. L05FC: POP DE ; retrieve pointer to start of word. XOR A ;; clear A CP B ;; compare to B zero RET ; return. with carry reset for success. ; --- L0600: PUSH DE ; save delimiter CALL L02B0 ; routine find zerobyte JP PO,L0614 ; jump if found to exit failure LD DE,($3C24) ; else set DE from L_HALF CALL L07FA ; routine SPACE_FILL (DE-HL) LD ($3C24),HL ; set L_HALF to next line POP DE ; restore delimiter JR L05E1 ; loop back using new line. ; --- ; branch here if a word not found. L0614: EX DE,HL ; DE addresses cursor. POP BC ; discard saved delimiter LD BC,$0000 ; set BC, to zero SCF ; signal not found RET ; return. ; -------------------------------- ; The 'stack length' Internal Word ; -------------------------------- ; used once only from LINE to check for any extraneous text that is not a Word ; or a Number. L061B: DEFW L061D ; headerless 'code field' ; --- L061D: CALL L05DF ; get buffer LD D,B ; transfer length of word LD E,C ; from BC to DE RST 10H ; push word DE JP (IY) ; to 'next'. ; ---------------- ; THE 'VLIST' WORD ; ---------------- ; List dictionary to screen, including words in ROM. ; (no pause after 18 lines) L0625: DEFM "VLIS" ; 'name field' DEFB 'T' + $80 DEFW L05AA ; 'link field' L062C: DEFB $05 ; 'name length field' L062D: DEFW L062F ; 'code field' ; --- L062F: LD A,$0D ; prepare a newline RST 08H ; print it. LD C,$00 ; set a flag for 'do all names'. JR L0644 ; forward to FIND. ; --------------- ; THE 'FIND' WORD ; --------------- ; ( -- compilation address ) ; Leaves compilation address of first word in input buffer, if defined in ; context vocabulary; else 0. L0636: DEFM "FIN" ; 'name field' DEFB 'D' + $80 DEFW L062C ; 'link field' L063C: DEFB $04 ; 'name length field' L063D: DEFW L063F ; 'code field' ; --- L063F: CALL L05DF ; get buffer word, gets length in C. JR C,L068A ; back if null to stack word zero ; -> L0644: LD HL,($3C33) ; fetch value of system variable CONTEXT LD A,(HL) ; extract low byte of address. INC HL ; increment pointer. LD H,(HL) ; extract high byte of address. LD L,A ; address now in HL. ; The address points to the 'name length field' of the most recent word in the ; Dictionary. L064B: LD A,(HL) ; fetch addressed byte. AND $3F ; discount bit 6, the immediate word ; indicator, to give length 1-31 JR Z,L067F ; a 'zero' length indicates this is a ; link like the example at the end of ; this ROM. XOR C ; match against C. JR Z,L0657 ; skip forward if lengths match. LD A,C ; test flag C AND A ; for value zero. JR NZ,L067F ; forward if C not zero. ; else a name that matches the search length or all names are required - VLIST. L0657: PUSH DE ; preserve DE PUSH HL ; preserve 'name length field' pointer. CALL L15E8 ; routine WORDSTART finds start of name. ; A is returned as zero. OR C ; test C for zero JR Z,L0676 ; branch forward to print if in VLIST. ; else the search is for a specific word and a word with same length, at least, ; has been found. LD B,C ; copy the length to counter B. L0660: LD A,(DE) ; fetch first letter of match word. CALL L0807 ; routine UPPERCASE INC DE ; update pointer (in lower screen) XOR (HL) ; match against letter (in dictionary). AND $7F ; disregard any inverted bit. INC HL ; increment dictionary pointer. JR NZ,L067D ; exit loop to try next link if no match DJNZ L0660 ; else loop back for all letters. ; Oh Frabjous day - a match. POP DE ; pop 'name length field' pointer. INC DE ; increment to point to compilation ; address. RST 10H ; stack date word DE. ; the remaining task is to clean up the input buffer in the lower screen. POP DE ; pop the DE - screen pointer. CALL L07DA ; clean up - backfill with spaces. JP (IY) ; to 'next'. ; ----------------------- ; THE 'PRINT NAME' BRANCH ; ----------------------- ; This branch is taken from the above loop when all found words are to be ; printed by VLIST. It takes its time as if the user has expanded the ; dictionary then the list will scroll off the top of the screen. By waiting ; for an interrupt each time, it ensures that a standard listing takes about ; three seconds and there is ample opportunity to press BREAK to stop at a ; certain point. L0676: CALL L17FB ; routine print string and space HALT ; wait for an interrupt. CALL L04E4 ; routine checks BREAK key. L067D: POP HL ; restore 'name length field' pointer POP DE ; restore DE L067F: DEC HL ; point to high byte of 'link field' LD A,(HL) ; hold it in A. DEC HL ; point to low byte of 'link field' LD L,(HL) ; transfer address of the new LD H,A ; 'name length field' to HL pointer. OR L ; test if address is zero - for the ; last entry in the linked list. JR NZ,L064B ; loop back while this is not the ; last entry in the vocabulary. L0687: DEFB $C3 ; A JP instruction i.e. JP L068A ; Note. The intention is to jump past the headerless code word for the internal ; word stk_zero. Since the word that would follow the first byte of the jump ; instruction would be identical to the word it is jumping over then the word ; can be omitted. Only saves one byte but this is back in 1983. ; ---------------------------- ; The 'stk-zero' Internal Word ; ---------------------------- ; ( -- 0 ) L0688: DEFW L068A ; headerless 'code field' ; --- L068A: LD DE,$0000 ; load DE with the value zero. RST 10H ; stack Data Word DE JP (IY) ; to 'next'. ; ------------------ ; THE 'EXECUTE' WORD ; ------------------ ; ( compilation address -- ) ; Executes the word with the given compilation address. L0690: DEFM "EXECUT" ; 'name field' DEFB 'E' + $80 DEFW L063C ; 'link field' L0699: DEFB $07 ; 'name length field' L069A: DEFW L069C ; 'code field' ; --- L069C: RST 18H JP L04BF ; ; ----------------- ; THE 'NUMBER' WORD ; ----------------- ; Takes a number from the start of the input buffer. Leaves the number and ; a non-zero address on the stack. (The address is the compilation address ; of a literal compiler, so that if you then say EXECUTE, the literal compiler ; compiles the number into the dictionary as a literal - for an integer it ; is 4102, for a floating point number it is 4181). ; If no valid number then leaves just 0 on the stack. L06A0: DEFM "NUMBE" ; 'name field' DEFB 'R' + $80 DEFW L0699 ; 'link field' L06A8: DEFB $06 ; 'name length field' L06A9: DEFW L06AB ; 'code field' ; --- L06AB: CALL L05DF ; get buffer JR C,L068A ; if empty stack word zero. PUSH BC PUSH DE CALL L074C ; JR NZ,L06BC ; LD DE,$1006 ; addr literal? JR L0714 ; ; --- L06BC: RST 18H ; pop word DE LD DE,$0000 RST 10H ; push word DE LD DE,$4500 POP BC PUSH BC LD A,(BC) CP $2D ; is it '-' ? JR NZ,L06CE ; LD D,$C5 INC BC L06CE: RST 10H ; push word DE LD D,B LD E,C DEC HL DEC HL L06D3: CALL L0723 ; routine GET_DECIMAL INC HL INC (HL) DEC HL JR NC,L06D3 ; CP $FE JR NZ,L071C ; L06DF: CALL L0723 ; routine GET_DECIMAL JR NC,L06DF ; ADD A,$30 ; add '0' converting to letter. CALL L077B ; JR NZ,L06EF ; LD E,$00 JR L06FD ; L06EF: AND $DF ; CP $45 ; is it 'E' - extended format? JR NZ,L071C ; PUSH HL CALL L074C ; RST 18H ; pop word DE POP HL JR NZ,L071C ; L06FD: CALL L0740 ; JR Z,L0711 ; INC HL LD A,(HL) AND $7F ADD A,E JP M,L071C ; forward +-> JR Z,L071C ; forward +-> XOR (HL) AND $7F XOR (HL) LD (HL),A L0711: LD DE,L1055 ; stk_fp L0714: RST 10H ; push word DE POP DE POP BC CALL L07DA ; JP (IY) ; to 'next'. ; --- ; +-> L071C: POP HL POP HL RST 18H ; pop word DE RST 18H ; pop word DE JP L068A ; ; ---------------------------- ; THE 'GET DECIMAL' SUBROUTINE ; ---------------------------- ; Fetch character and return with carry set if after conversion is not in ; range 0 to 9. L0723: LD A,(DE) INC DE SUB $30 ; subtract '0' RET C ; return if was less than '0' CP $0A ; compare to ten. CCF ; complement RET C ; return - with carry set if over 9. ; --------- ; normalize? ; --------- ; => from below only. L072C: LD C,A LD A,(HL) AND $F0 RET NZ LD A,C ; => (int/print_fp) L0732: DEC HL DEC HL LD C,$03 L0736: RLD ; A = xxxx3210 <-- 7654<-3210 (HL) INC HL ; DEC C JR NZ,L0736 ; DEC (HL) ; decrement exponent DEC HL ; point to start of BCD nibbles CP A RET ; --- ; from ufloat to normalize 6-nibble mantissa L0740: LD B,$06 ; six nibbles L0742: XOR A CALL L072C ; RET NZ DJNZ L0742 ; INC HL LD (HL),B RET ; --------------------------- ; THE 'GET NUMBER' SUBROUTINE ; --------------------------- ; can be called twice by the above code for the word 'NUMBER'. ; Once to get the first number encountered and sometimes, if in extended ; format, the exponent as well. L074C: RST 10H ; push word DE CALL L04B9 ; forth L0750: DEFW L086B ; dup DEFW L0896 ; C@ DEFW L104B ; stk-data DEFB $2D ; chr '-' DEFW L0C4A ; = DEFW L086B ; dup DEFW L0DA9 ; negate DEFW L08D2 ; >R DEFW L0DD2 ; + DEFW L0E1F ; 1- DEFW L0688 ; stk-zero DEFW L0688 ; stk-zero DEFW L08FF ; rot L0769: DEFW L078A ; convert DEFW L08FF ; rot DEFW L08DF ; R> DEFW L0D94 ; pos DEFW L08FF ; rot DEFW L0879 ; drop DEFW L0885 ; swap DEFW L1A0E ; end-forth. L0779: RST 18H ; pop word DE LD A,(DE) L077B: CP $20 RET Z AND A RET ; ------------------ ; THE 'CONVERT' WORD ; ------------------ ; ( ud1, addr1 -- ud2, addr2 ) : Accumulates digits from text into an unsigned double length ; number ud1: for each digit, the double length accumulator is ; multiplied by the system number base and the digit (converted ; from ASCII) is added on. The text starts at addr1 + 1. addr2 is ; the address of the first unconvertible character, ud2 is the ; final value of the accumulator. L0780: DEFM "CONVER" ; 'name field' DEFB 'T' + $80 DEFW L06A8 ; 'link field' L0789: DEFB $07 ; 'name length field' L078A: DEFW L0EC3 ; 'code field' - docolon ; --- L078C: DEFW L0E09 ; 1+ L078E: DEFW L086B ; dup L0790: DEFW L08D2 ; >R L0792: DEFW L0896 ; C@ L0794: DEFW L07B8 ; stk_digit L0796: DEFW L1283 ; ?branch L0798: DEFW $001B ; to 0799 + 1B = $07B4 L079A: DEFW L0885 ; swap L079C: DEFW L048A ; get base L079E: DEFW L0896 ; C@ L07A0: DEFW L0CA8 ; u* L07A2: DEFW L0879 ; drop L07A4: DEFW L08FF ; rot L07A6: DEFW L048A ; get base L07A8: DEFW L0896 ; C@ L07AA: DEFW L0CA8 ; U* L07AC: DEFW L0DEE ; D+ L07AE: DEFW L08DF ; R> L07B0: DEFW L1276 ; branch L07B2: DEFW $FFD9 ; loop back to L078C L07B4: DEFW L08DF ; R> L07B6: DEFW L04B6 ; exit ; ----------------------------- ; The 'stk_digit' Internal Word ; ----------------------------- L07B8: DEFW L07BA ; headerless 'code field' ; --- L07BA: RST 18H ; pop word DE LD A,E ; character to A CALL L0807 ; to_upper ADD A,$D0 ; add to give carry with '0' and more. JR NC,L07D7 ; if less than '0' push byte 0 false. CP $0A ; compare to ten. JR C,L07CD ; forward to stack bytes 0 - 9. ADD A,$EF ; JR NC,L07D7 ; push word false 0. ADD A,$0A L07CD: CP (IX+$3F) ; compare to BASE JR NC,L07D7 ; push word false 0. ; else digit is within range of number base LD D,$00 LD E,A RST 10H ; push word DE SCF ; set carry to signal true L07D7: JP L0C21 ; push word 1 or 0 ; --- ; ?? ; --- L07DA: LD H,D LD L,E INC BC ADD HL,BC PUSH HL BIT 4,(IX+$3E) ; FLAGS CALL Z,L097F ; pr_string CALL L02B0 ; curs? POP DE AND A SBC HL,DE LD B,H LD C,L LD HL,($3C1E) ; INSCRN INC HL EX DE,HL JR C,L07FB ; JR Z,L07FA ; forward to SPACE_FILL. LDIR ; ------------------------ ; The 'SPACE FILL' routine ; ------------------------ ; -> from cls L07FA: AND A ; prepare to subtract two screen ; pointers. L07FB: SBC HL,DE ; number of bytes in HL. EX DE,HL ; now in DE, HL = start of area. L07FE: LD A,D ; check if the OR E ; counter is zero. RET Z ; return if so. >> LD (HL),$20 ; insert a space character. INC HL ; next address. DEC DE ; decrement byte counter. JR L07FE ; loop back to exit on zero. ; -------------------------- ; THE 'UPPERCASE' SUBROUTINE ; -------------------------- ; converts characters to uppercase. L0807: AND $7F ; ignore inverse bit 7 CP $61 ; compare to 'a' RET C ; return if lower CP $7B ; compare to 'z' + 1 RET NC ; return if higher than 'z' AND $5F ; make uppercase RET ; return. ; -------------- ; THE 'VIS' WORD ; -------------- ; Allows copy-up mechanism and 'OK'. L0812: DEFM "VI" ; 'name field' DEFB 'S' + $80 DEFW L0789 ; 'link field' L0817: DEFB $03 ; 'name length field' L0818: DEFW L081A ; 'code field' ; --- L081A: RES 4,(IX+$3E) ; update FLAGS signal visible mode. JP (IY) ; to 'next'. ; ---------------- ; THE 'INVIS' WORD ; ---------------- ; Suppresses copy-up mechanism and 'OK'. L0820: DEFM "INVI" ; 'name field' DEFB 'S' + $80 DEFW L0817 ; 'link field' L0827: DEFB $05 ; 'name length field' L0828: DEFW L082A ; 'code field' ; --- L082A: SET 4,(IX+$3E) ; update FLAGS signal invisible mode. JP (IY) ; to 'next'. ; --------------- ; THE 'FAST' WORD ; --------------- ; Fast mode - runs without error checks. ; Debugged programs run 25% faster. L0830: DEFM "FAS" ; 'name field' DEFB 'T' + $80 DEFW L0827 ; 'link field' L0836: DEFB $04 ; 'name length field' L0837: DEFW L0839 ; 'code field' ; --- L0839: LD IY,L04B9 ; miss memory checks on return JP (IY) ; to 'next'. ; --------------- ; THE 'SLOW' WORD ; --------------- ; ( -- ) ; Slow mode with error checking. ; Make IY point to a return routine that performs housekeeping. L083F: DEFM "SLO" ; 'name field' DEFB 'W' + $80 DEFW L0836 ; 'link field' L0845: DEFB $04 ; 'name length field' L0846: DEFW L0848 ; 'code field' ; --- L0848: LD IY,L04C8 ; set vector to memory checks each pass JP (IY) ; to 'next'. ; --------------------------------- ; THE 'DATA STACK TO BC' SUBROUTINE ; --------------------------------- ; Called on twenty occasions to fetch a word from the Data Stack into the ; BC register pair. Very similar to RST 18H which does the same thing with the ; DE register pair as the destination on 73 occasions. ; In fact, as two Z80 restarts are unused, then 40 bytes of ROM code could have ; been saved by making this a restart also. L084E: LD HL,($3C3B) ; fetch SPARE - start of Spare Memory. DEC HL ; decrement to point to last stack item LD B,(HL) ; load high byte to B. DEC HL ; address low byte of word. LD C,(HL) ; and load to C. LD ($3C3B),HL ; update the system variable SPARE to ; a location two bytes less than it was. RET ; return. ; ----------------------------------------- ; THE 'CONTINUATION OF THE RST 18H' RESTART ; ----------------------------------------- ; complete the operation of popping a word to DE from the data stack. L0859: DEC HL ; LD E,(HL) ; LD ($3C3B),HL ; update SPARE RET ; return. ; ----------------------------------------- ; THE 'CONTINUATION OF THE RST 10H' RESTART ; ----------------------------------------- ; complete the operation of pushing a word in DE to the data stack. L085F: LD (HL),D ; INC HL ; LD ($3C3B),HL ; update SPARE RET ; return. ; -------------- ; THE 'DUP' WORD ; -------------- ; ( n -- n, n ) ; Duplicates the top of the stack. L0865: DEFM "DU" ; 'name field' DEFB 'P' + $80 DEFW L0845 ; 'link field' L086A: DEFB $03 ; 'name length field' L086B: DEFW L086D ; 'code field' ; --- L086D: RST 18H ; unstack Data Word DE RST 10H ; stack Data Word DE RST 10H ; stack Data Word DE JP (IY) ; to 'next'. ; --------------- ; THE 'DROP' WORD ; --------------- ; ( n -- ) ; Throws away the top of the stack. L0872: DEFM "DRO" ; 'name field' DEFB 'P' + $80 DEFW L086A ; 'link field' L0878: DEFB $04 ; 'name length field' L0879: DEFW L087B ; 'code field' ; --- L087B: RST 18H ; unstack Data Word DE JP (IY) ; to 'next'. ; --------------- ; THE 'SWAP' WORD ; --------------- ; (n1, n2 -- n2, n1) L087E: DEFM "SWA" ; 'name field' DEFB 'P' + $80 DEFW L0878 ; 'link field' L0884: DEFB $04 ; 'name length field' L0885: DEFW L0887 ; 'code field' ; --- L0887: RST 18H ; pop word DE CALL L084E ; stk_to_bc RST 10H ; push word DE LD D,B ; LD E,C ; RST 10H ; push word DE JP (IY) ; to 'next'. ; ------------- ; THE 'C@' WORD ; ------------- ; (address -- byte) ; Fetches the contents of a given address. L0891: DEFB 'C' ; 'name field' DEFB '@' + $80 DEFW L0884 ; 'link field' L0895: DEFB $02 ; 'name length field' L0896: DEFW L0898 ; 'code field' ; --- L0898: RST 18H ; pop word DE LD A,(DE) LD E,A LD D,$00 RST 10H ; push word DE JP (IY) ; to 'next'. ; ------------- ; THE 'C!' WORD ; ------------- ; (n, address -- ) ; Stores the less significant byte on n at a given address. L08A0: DEFB 'C' ; 'name field' DEFB '!' + $80 DEFW L0895 ; 'link field' L08A4: DEFB $02 ; 'name length field' L08A5: DEFW L08A7 ; 'code field' ; --- L08A7: RST 18H ; pop word DE CALL L084E ; stk_to_bc LD A,C LD (DE),A JP (IY) ; to 'next'. ; ------------ ; THE '@' WORD ; ------------ ; (address -- n) ; Leaves on stack the single length integer at the given address. L08AF: DEFB '@' + $80 ; 'name field' DEFW L08A4 ; 'link field' L08B2: DEFB $01 ; 'name length field' L08B3: DEFW L08B5 ; 'code field' ; --- L08B5: RST 18H ; pop word DE EX DE,HL LD E,(HL) INC HL LD D,(HL) RST 10H ; push word DE JP (IY) ; to 'next'. ; ------------ ; THE '!' WORD ; ------------ ; (n,address --) ; Stores the single-length integer n at the given address in memory. L08BD: DEFB '!' + $80 ; 'name field' DEFW L08B2 ; 'link field' L08C0: DEFB $01 ; 'name length field' L08C1: DEFW L08C3 ; 'code field' ; --- L08C3: RST 18H ; pop word DE CALL L084E ; stk_to_bc EX DE,HL LD (HL),C INC HL LD (HL),B JP (IY) ; to 'next'. ; ------------- ; THE '>R' WORD ; ------------- ; (n -- ) ; Transfers top entry on data stack to return stack. ; It can be copied back using 'I'. L08CD: DEFB '>' ; 'name field' DEFB 'R' + $80 DEFW L08C0 ; 'link field' L08D1: DEFB $02 ; 'name length field' L08D2: DEFW L08D4 ; 'code field' ; --- L08D4: RST 18H POP BC PUSH DE PUSH BC JP (IY) ; to 'next'. ; ------------- ; THE 'R>' WORD ; ------------- ; ( -- entry from return stack) ; Transfers top entry on return stack to data stack. L08DA: DEFB 'R' ; 'name field' DEFB '>' + $80 DEFW L08D1 ; 'link field' L08DE: DEFB $02 ; 'name length field' L08DF: DEFW L08E1 ; 'code field' ; --- L08E1: POP BC POP DE PUSH BC RST 10H ; push word DE JP (IY) ; to 'next'. ; --------------- ; THE '?DUP' WORD ; --------------- ; (n -- n, n) if n!=0. ; (n -- n) if n=0. L08E7: DEFM "?DU" ; 'name field' DEFB 'P' + $80 DEFW L08DE ; 'link field' L08ED: DEFB $04 ; 'name length field' L08EE: DEFW L08F0 ; 'code field' ; --- L08F0: RST 18H ; fetch word DE RST 10H ; push it back LD A,D ; test if fetched OR E ; word is zero CALL NZ,L0010 ; push word DE if non-zero JP (IY) ; to 'next'. ; -------------- ; THE 'ROT' WORD ; -------------- ; (n1, n2, n3 -- n2, n3, n1) L08F9: DEFM "RO" ; 'name field' DEFB 'T' + $80 DEFW L08ED ; 'link field' L08FE: DEFB $03 ; 'name length field' L08FF: DEFW L0EC3 ; 'code field' - docolon ; --- L0901: DEFW L08D2 ; >R L0903: DEFW L0885 ; swap L0905: DEFW L08DF ; R> L0907: DEFW L0885 ; swap L0909: DEFW L04B6 ; exit ; --------------- ; THE 'OVER' WORD ; --------------- ; (n1, n2 -- n1, n2, n1) L090B: DEFM "OVE" ; 'name field' DEFB 'R' + $80 DEFW L08FE ; 'link field' L0911: DEFB $04 ; 'name length field' L0912: DEFW L0EC3 ; 'code field' - docolon ; --- L0914: DEFW L08D2 ; >R L0916: DEFW L086B ; dup L0918: DEFW L08DF ; R> L091A: DEFW L0885 ; swap L091C: DEFW L04B6 ; exit ; --------------- ; THE 'PICK' WORD ; --------------- ; (n1 -- n2) ; Copies the n1-th stack entry (after dropping n1 itself) to the top. ; Error 7 if n1 <= 0. L091E: DEFM "PIC" ; 'name field' DEFB 'K' + $80 DEFW L0911 ; 'link field' L0924: DEFB $04 ; 'name length field' DEFW L0927 ; 'code field' ; --- L0927: CALL L094D ; JP (IY) ; to 'next'. ; --------------- ; THE 'ROLL' WORD ; --------------- ; (n -- ) ; Extracts the nth stack value to the top of the stack, after dropping n ; itself, and moves the remaining values down to fill the vacated position. ; Error 7 if n <= 0. L092C: DEFM "ROL" ; 'name field' DEFB 'L' + $80 DEFW L0924 ; 'link field' L0932: DEFB $04 ; 'name length field' L0933: DEFW L0935 ; 'code field' ; --- L0935: CALL L094D ; EX DE,HL LD HL,($3C37) ; STKBOT SBC HL,DE JP NC,L04D7 ; jump back to Error 2 LD H,D LD L,E INC HL INC HL LDIR LD ($3C3B),DE ; SPARE JP (IY) ; to 'next'. ; --- L094D: CALL L084E ; stk_to_bc DEC BC SLA C RL B INC BC INC BC JR NC,L095B ; skip the error routine RST 20H ; Error 7 DEFB $07 ; PICK or ROLL used with operand 0 ; or negative ; --- L095B: LD HL,($3C3B) ; SPARE SBC HL,BC PUSH HL LD E,(HL) INC HL LD D,(HL) RST 10H ; push word DE POP HL RET ; --------------- ; THE 'TYPE' WORD ; --------------- ; (address, n -- ) ; EMITs n characters from memory starting at the address. L0967: DEFM "TYP" ; 'name field' DEFB 'E' + $80 DEFW L0932 ; 'link field' L096D: DEFB $04 ; 'name length field' L096E: DEFW L0970 ; 'code field' ; --- L0970: CALL L084E ; stk_to_bc RST 18H ; pop word DE CALL L097F ; routine pr_string (below) JP (IY) ; to 'next'. ; -------------------------- ; THE 'PRINT STRING' ROUTINE ; -------------------------- ; The first entry point prints strings embedded in the Dictionary with the ; DE pointing to the preceding length word. ; ; The second entry point prints a string with length in BC and start in DE. ; It is called by TYPE above and to print comment fields. ; -> L0979: LD A,(DE) LD C,A INC DE LD A,(DE) LD B,A INC DE ; --> L097F: LD A,B OR C RET Z LD A,(DE) INC DE DEC BC RST 08H ; print_ch JR L097F ; ; ------------- ; THE '<#' WORD ; ------------- ; ( -- ) ; Initiates formatted output. L0988: DEFB '<' ; 'name field' DEFB '#' + $80 DEFW L096D ; 'link field' L098C: DEFB $02 ; 'name length field' L098D: DEFW L098F ; 'code field' ; --- L098F: LD HL,$27FF ; end of pad LD ($3C1A),HL ; update system variable HLD JP (IY) ; to 'next'. ; ------------- ; THE '#>' WORD ; ------------- ; (ud -- address, n) ; Finishes formatted output, leaving the address and length (n) of the ; resultant string. L0997: DEFB '#' ; 'name field' DEFB '>' + $80 DEFW L098C ; 'link field' L099B: DEFB $02 ; 'name length field' L099C: DEFW L099E ; 'code field' ; --- L099E: RST 18H ; pop word DE RST 18H ; pop word DE LD DE,($3C1A) ; HLD RST 10H ; push word DE (address) LD HL,$27FF ; end of pad. AND A ; prepare to subtract. SBC HL,DE ; find length of string. EX DE,HL ; transfer to DE RST 10H ; push word DE (n) JP (IY) ; to 'next'. ; ------------ ; THE '.' WORD ; ------------ ; L09AF: DEFB '.' + $80 ; 'name field' DEFW L0A49 ; 'link field' L09B2: DEFB $01 ; 'name length field' L09B3: DEFW L0EC3 ; 'code field' - docolon ; --- L09B5: DEFW L098D ; <# DEFW L086B ; dup DEFW L0C0D ; abs DEFW L0688 ; stk-zero DEFW L09E1 ; #s DEFW L08FF ; rot DEFW L0A4A ; sign L09C3: DEFW L099C ; #> DEFW L096E ; type DEFW L0A73 ; space DEFW L04B6 ; exit ; ------------- ; THE 'U.' WORD ; ------------- ; (un -- ) ; Prints the unsigned single length integer 'un' to the television screen, ; followed by a space. L09CB: DEFB 'U' ; 'name field' DEFB '.' + $80 DEFW L09B2 ; 'link field' L09CF: DEFB $02 ; 'name length field' L09D0: DEFW L0EC3 ; 'code field' - docolon ; --- L09D2: DEFW L0688 ; stk-zero L09D4: DEFW L098D ; <# L09D6: DEFW L09E1 ; #S L09D8: DEFW L1276 ; branch L09DA: DEFW $FFE8 ; -> 09C3 ; ------------- ; THE '#S' WORD ; ------------- ; (ud -- 0,0) ; Applies # repeatedly (at least once) until the double length number left ; on the stack is 0. L09DC: DEFB '#' ; 'name field' DEFB 'S' + $80 DEFW L09CF ; 'link field' L09E0: DEFB $02 ; 'name length field' L09E1: DEFW L0EC3 ; 'code field' - docolon ; --- L09E3: DEFW L09F7 ; # DEFW L0912 ; over DEFW L0912 ; over DEFW L0E36 ; or DEFW L0C1A ; 0= DEFW L128D ; ?branch L09EF: DEFW $FFF3 ; back to L09E3 DEFW L04B6 ; exit ; ------------ ; THE '#' WORD ; ------------ ; (ud1 -- ud2) ; used in formatted output. Generates one digit from the unsigned double ; length integer ud1 and holds it in the pad. The unsigned double length ; integer ud2 is the quotient when ud1 is divided by the number base. L09F3: DEFB '#' + $80 ; 'name field' DEFW L09E0 ; 'link field' L09F6: DEFB $01 ; 'name length field' L09F7: DEFW L0EC3 ; 'code field' - docolon ; --- L09F9: DEFW L048A ; get base L09FB: DEFW L0896 ; C@ L09FD: DEFW L0CC4 ; div? L09FF: DEFW L08FF ; rot L0A01: DEFW L0A07 ; stk-char L0A03: DEFW L0A5C ; hold L0A05: DEFW L04B6 ; exit ; ---------------------------- ; The 'stk-char' Internal Word ; ---------------------------- ; used from above thread. L0A07: DEFW L0A09 ; headerless 'code field' ; --- L0A09: RST 18H ; data stack to DE LD A,E ; character to A ADD A,$30 ; convert digit to ASCII CP $3A ; compare to '9' JR C,L0A13 ; forward if digit ADD A,$07 ; else add for hex L0A13: LD E,A ; back to E RST 10H ; push ASCII on data stack. JP (IY) ; to 'next'. ; -------------- ; THE 'CLS' WORD ; -------------- ; ( -- ) ; Clears the screen and sets the print position to the top left of ; the screen. L0A17: DEFM "CL" ; 'name field' DEFB 'S' + $80 DEFW L09F6 ; 'link field' L0A1C: DEFB $03 ; 'name length field' DEFW L0A1F ; 'code field' ; --- L0A1F: CALL L0A24 ; routine CLS below. JP (IY) ; to 'next'. ; -------------------- ; THE 'CLS' SUBROUTINE ; -------------------- ; Called from the 'CLS' word definition above and also from the initialization ; routine. L0A24: LD DE,$26FF ; point destination to end of video ; memory. LD HL,($3C24) ; set HL to first byte of input buffer ; from system variable L_HALF. ; (at initialization $26E0). LD BC,$0020 ; set count to thirty two. ADD HL,BC ; add to the low address. DEC HL ; step back and LDDR ; copy the 32 bytes. ; while BC is zero, set the plotting coordinates. LD ($3C2F),BC ; set XCOORD and YCOORD to zero. ; set the screen position to the start of video memory. LD HL,$2400 ; start of the 768 bytes of video RAM. LD ($3C1C),HL ; set system variable SCRPOS. INC DE ; the byte before logical line. EX DE,HL ; transfer to HL. LD ($3C24),HL ; set L_HALF. JP L07FA ; jump back to fill the locations ; from DE to HL -1 with spaces. ; --------------- ; THE 'SIGN' WORD ; --------------- ; (n -- ) ; In formatted output, holds a minus sign in the pad if n is negative. L0A43: DEFM "SIG" ; 'name field' DEFB 'N' + $80 DEFW L099B ; 'link field' L0A49: DEFB $04 ; 'name length field' L0A4A: DEFW L0A4C ; 'code field' ; --- L0A4C: RST 18H ; pop word DE RL D ; test sign bit LD E,$2D ; prepare a '-' JR C,L0A5F ; forward if minus JP (IY) ; to 'next'. ; --------------- ; THE 'HOLD' WORD ; --------------- ; (character -- ) ; Used in formatted output to hold the character in the pad. L0A55: DEFM "HOL" ; 'name field' DEFB 'D' + $80 L0A59: DEFW L0A1C ; 'link field' L0A5B: DEFB $04 ; 'name length field' L0A5C: DEFW L0A5E ; 'code field' ; --- L0A5E: RST 18H ; data stack to DE L0A5F: LD HL,($3C1A) ; HLD DEC L JR Z,L0A69 ; forward when full LD ($3C1A),HL ; update HLD LD (HL),E ; and place character in buffer L0A69: JP (IY) ; to 'next'. ; ---------------- ; THE 'SPACE' WORD ; ---------------- ; ( -- ) ; EMITs a space. L0A6B: DEFM "SPAC" ; 'name field' DEFB 'E' + $80 DEFW L0A5B ; 'link field' L0A72: DEFB $05 ; 'name length field' L0A73: DEFW L0A75 ; 'code field' ; --- L0A75: LD A,$20 ; load accumulator with the ASCII ; code for space. RST 08H ; print_ch L0A78: JP (IY) ; to 'next'. ; ----------------- ; THE 'SPACES' WORD ; ----------------- ; (n -- ) ; EMITs n spaces if n >= 1. L0A7A: DEFM "SPACE" ; 'name field' DEFB 'S' + $80 DEFW L0A72 ; 'link field' L0A82: DEFB $06 ; 'name length field' DEFW L0A85 ; 'code field' ; --- L0A85: RST 18H ; fetch stack data to DE L0A86: DEC DE ; decrement the counter. BIT 7,D ; test for a negative value JR NZ,L0A78 ; back to a jp iy when done >> LD A,$20 ; prepare a space RST 08H ; print it JR L0A86 ; loop back for more. ; ------------- ; THE 'CR' WORD ; ------------- ; Outputs a carriage return character to the television. L0A90: DEFB 'C' ; 'name field' DEFB 'R' + $80 DEFW L0A82 ; 'link field' L0A94: DEFB $02 ; 'name length field' L0A95: DEFW L0A97 ; 'code field' ; --- L0A97: LD A,$0D ; prepare a CR RST 08H ; print it. JP (IY) ; to 'next'. ; --------------- ; THE 'EMIT' WORD ; --------------- ; (character -- ) ; writes the character to the television screen. L0A9C: DEFM "EMI" ; 'name field' DEFB 'T' + $80 DEFW L0A94 ; 'link field' L0AA2: DEFB $04 ; 'name length field' L0AA3: DEFW L0AA5 ; 'code field' ; --- L0AA5: RST 18H ; pop de off data stack LD A,E ; character to A RST 08H ; print it. JP (IY) ; to 'next'. ; ------------- ; THE 'F.' WORD ; ------------- ; (f -- ) ; print a floating point number. ; If 1.0E-4 <= f < 1.0E9, then f is printed without an exponent and with a ; decimal point in the appropriate place. If f is outside this range, then ; it is printed in standard form f'En where 0 <= f' < 10 and -64 <= n <= 62. ; Input may be either form, but only six significant digits are accepted - ; further digits are ignored. ; Floating point numbers are stored as 3 bytes of binary coded decimal ; mantissa and 1 byte for sign and decimal exponents. ; ; e.g. the number 123.456 on Data Stack would be two words, four bytes. ; ; ^ 43 01000011 bits 5 - 0 are exponent ; | 12 BCD || ; | 34 BCD |sign of exponent 1=positive (bit 6) ; | 56 BCD sign of number 0=positive (bit 7) ; ; Zero 0. is a special case floating point number with all four bytes set ; to zero. L0AAA: DEFB 'F' ; 'name field' DEFB '.' + $80 DEFW $0AA2 ; 'link field' L0AAE: DEFB $02 ; 'name length field' L0AAF: DEFW $0AB1 ; 'code field' ; --- L0AB1: LD HL,($3C3B) ; set pointer from system variable SPARE DEC HL ; now points to last byte of data stack. BIT 7,(HL) ; test sign of number. RES 7,(HL) ; reset the sign bit. JR Z,L0ABE ; forward if initially positive. LD A,$2D ; prepare the '-' character. RST 08H ; print the minus sign. ; The E register is initialized to zero to denote not E-FORMAT L0ABE: LD E,$00 ; signal not scientific notation. LD A,(HL) ; fetch exponent byte DEC A ; adjust to make zero $FF CP $49 ; compare to +9 e.g. 123456000. JR NC,L0ACA ; skip forward if out of range. CP $3C ; compare to -4 e.g .000123456 JR NC,L0ACE ; skip forward if in range. ; else E format printing will be used with decimal point after first digit. L0ACA: LD (HL),$41 ; make Data Stack exponent +1 INC A ; restore true exponent byte LD E,A ; transfer to E. ; the branch was here when within range for normal printing. L0ACE: LD A,$40 ; test value is plus zero. SUB (HL) ; subtract signed exponent. JR C,L0ADC ; forward if positive ; exponent is negative so decimal point comes first. e.g. .001 LD B,A ; result of subtraction to B. INC B ; B is now one less than count of ; leading zeros. LD A,$2E ; prepare '.' L0AD7: RST 08H ; print decimal point or zero. LD A,$30 ; prepare a zero - '0' DJNZ L0AD7 ; loop back to print leading zeros ; unless the counter was 1. ; the branch was here with positive exponent (and zero) ; now enter a loop to print each of the leading BCD digits ; the loop will end when the exponent is <= +0 and all 6 nibbles contain zero. L0ADC: LD A,$40 ; set accumulator to plus 0 CP (HL) ; compare to exponent on data stack. SBC A,A ; $FF if more leading digits else $00. DEC HL ; address first two nibbles. OR (HL) ; combine. DEC HL ; address next two nibbles. OR (HL) ; combine. DEC HL ; address last two nibbles. OR (HL) ; combine. INC HL ; adjust the pointer to INC HL ; the start of the mantissa. JR Z,L0AFC ; forward if all digits have been ; printed. ; else print each binary coded decimal in turn. XOR A ; prepare to feed a zero nibble in. CALL L0732 ; routine shift_fp extracts the most ; significant nibble from the 3 bytes ; also decrementing the exponent. ADD A,$30 ; convert to ASCII RST 08H ; print digit INC HL ; point to reduced exponent. LD A,(HL) ; fetch to accumulator and CP $40 ; compare to zero. JR NZ,L0ADC ; loop back while more digits. ; else this is the place to print the mid or trailing decimal point. LD A,$2E ; prepare '.' RST 08H ; print it. JR L0ADC ; loop back for end test and any digits ; following the decimal point. ; --- ; the branch was to here when all digits of the mantissa have been printed. L0AFC: LD A,E ; fetch the exponent format flag - from ; the E register appropriately. AND A ; test for zero - normal format. JR NZ,L0B05 ; forward to E_FORMAT if not. LD A,$20 ; else prepare a space RST 08H ; print it JR L0B10 ; forward to delete the two words from ; the data stack and exit. ; --- ; this branch deals with scientific notation. The accumulator holds the ; original exponent. $01-$3C (negative) $49-$7F (positive). L0B05: SUB $41 ; convert to signed 8-bit. LD L,A ; low order byte to L. SBC A,A ; $FF negative or $00 positive LD H,A ; set the high order byte. LD A,$45 ; prepare a 'E' RST 08H ; print it CALL L180E ; routine pr_int_hl prints the signed ; integer followed by a space. ; finally delete the floating point number from the Data Stack. L0B10: RST 18H ; unstack word DE RST 18H ; unstack word DE JP (IY) ; to 'next'. ; ------------- ; THE 'AT' WORD ; ------------- ; (line, column -- ) ; Sets print position to line and column numbers on the stack. ; There are 23 lines (0 to 22) and 32 columns (0 to 31). The ; column number is taken modulo 32, and ERROR 9 if trying to print ; in the input buffer at the bottom. L0B14: DEFB 'A' ; 'name field' DEFB 'T' + $80 DEFW L0AAE ; 'link field' L0B18: DEFB $02 ; 'name length field' DEFW L0B1B ; 'code field' ; --- L0B1B: RST 18H ; pop word DE CALL L084E ; stk_to_bc LD A,C CALL L0B28 ; LD ($3C1C),HL ; update system variable SCRPOS JP (IY) ; to 'next'. ; --- ; plotsub L0B28: ADD A,$20 LD L,A LD H,$01 ADD HL,HL ADD HL,HL ADD HL,HL ADD HL,HL ADD HL,HL LD D,$00 LD A,E AND $1F LD E,A ADD HL,DE LD DE,($3C24) ; fetch start of lower half from L_HALF SBC HL,DE ADD HL,DE RET C ; RST 20H ; Error 9 DEFB $09 ; Erroneous 'AT' Command. ; --------------- ; THE 'PLOT' WORD ; --------------- ; (x, y, n -- ) ; Plots pixel (x, y) with plot mode n. ; n = 0 unplot ; 1 plot ; 2 move ; 3 change ; If n>3, takes value modulo 4. L0B43: DEFM "PLO" ; 'name field' DEFB 'T' + $80 DEFW L0B18 ; 'link field' L0B49: DEFB $04 ; 'name length field' DEFW L0B4C ; 'code field' ; --- L0B4C: CALL L084E ; stk_to_bc RST 18H ; pop word DE LD (IX+$30),E ; YCOORD SRL E RL C LD A,$16 ; 24 SUB E RST 18H ; pop word DE LD (IX+$2F),E ; XCOORD SRL E RL C CALL L0B28 ; LD A,(HL) AND $78 ; 01111000 CP $10 LD A,(HL) JR Z,L0B6F ; LD A,$10 L0B6F: LD E,A LD D,$87 LD A,C AND $03 LD B,A JR Z,L0B7F ; CPL ADD A,$02 ADC A,$03 LD D,A LD B,E L0B7F: LD A,C RRCA RRCA RRCA SBC A,A BIT 3,C JR NZ,L0B8C ; XOR E RLCA SBC A,A XOR B L0B8C: AND D XOR E LD (HL),A JP (IY) ; to 'next'. ; --------------- ; THE 'BEEP' WORD ; --------------- ; ( m, n -- ) ; Plays a note on the loudspeaker. 8 * m = period in microseconds, ; n = time in milliseconds. L0B91: DEFM "BEE" ; 'name field' DEFB 'P' + $80 DEFW L0B49 ; 'link field' L0B97: DEFB $04 ; 'name length field' DEFW L0EC3 ; 'code field' m, n. ; --- L0B9A: DEFW L0912 ; OVER m, n, m. DEFW L104B ; stk-data m, n, m, 125. DEFB $7D ; (125) DEFW L0885 ; SWAP m, n, 125, m. DEFW L0D7A ; */ m, (n*125)/m DEFW L1A0E ; end ; --- L0BA5: RST 18H ; pop word DE CALL L084E ; stk_to_bc LD HL,$00F9 ; ADD HL,BC ; INC L ; DI ; Disable Interrupts. L0BAF: LD A,$7F ; place $7FFE on address bus and read IN A,($FE) ; from port, pushing the loudspeaker ; diaphragm in. RRCA ; test the read 'SPACE' key bit. JR NC,L0BC7 ; forward if BREAK pressed. CALL L0BC9 ; routine delay_HL DEC DE ; decrement counter. LD A,D ; all even addresses are reserved for ; Jupiter Ace so any value does for the ; high order byte. $FE is low value. OUT ($FE),A ; push the loudspeaker diaphragm out. CALL L0BC9 ; routine delay_HL OR E ; test for counter DE reaching zero. JP NZ,L0BAF ; loop back if not. EI ; Enable Interrupts. JP (IY) ; to 'next'. ; --- L0BC7: RST 20H ; Error 3 DEFB $03 ; BREAK pressed. ; --------------------------- ; THE 'BEEP DELAY' SUBROUTINE ; --------------------------- ; called twice from the above BEEP routine. L0BC9: LD B,L ; transfer the value of LD C,H ; the HL register to BC. L0BCB: DJNZ L0BCB ; self-loop for B times DEC B ; set B to $FF for future loops DEC C ; decrement outer loop counter C JP NZ,L0BCB ; JUMP back if not zero (10) RET ; return ; ---------------- ; THE 'INKEY' WORD ; ---------------- ; ( -- ASCII code) ; Reads the keyboard. Puts ASCII value on the stack if a key is pressed, 0 ; otherwise. L0BD3: DEFM "INKE" ; 'name field' DEFB 'Y' + $80 DEFW L0B97 ; 'link field' L0BDA: DEFB $05 ; 'name length field' L0BDB: DEFW L0BDD ; 'code field' ; --- L0BDD: CALL L0336 ; routine KEY-SCAN LD E,A ; transfer the key code to E. LD D,$00 ; make high order byte zero. RST 10H ; stack Data Word DE JP (IY) ; to 'next'. ; ------------- ; THE 'IN' WORD ; ------------- ; (port address -- data byte) ; Inputs a data byte from an I/O port. L0BE6: DEFB 'I' ; 'name field' DEFB 'N' + $80 DEFW L0BDA ; 'link field' L0BEA: DEFB $02 ; 'name length field' DEFW L0BED ; 'code field' ; --- L0BED: CALL L084E ; stk_to_bc LD D,$00 ; make high order byte zero. IN E,(C) ; read the port to E. RST 10H ; stack Data Word DE. L0BF5: JP (IY) ; to 'next'. ; -------------- ; THE 'OUT' WORD ; -------------- ; (data byte, port address -- ) ; Outputs a data byte to an I/O port. L0BF7: DEFM "OU" ; 'name field' DEFB 'T' + $80 DEFW L0BEA ; 'link field' L0BFC: DEFB $03 ; 'name length field' DEFW L0BFF ; 'code field' ; --- L0BFF: CALL L084E ; stk_to_bc ; all 16 bits are placed on the ; Z80A address bus. RST 18H ; pop word DE OUT (C),E ; output byte to port address. JP (IY) ; to 'next'. ; -------------- ; THE 'ABS' WORD ; -------------- ; (n -- absolute value of n) L0C07: DEFM "AB" ; 'name field' DEFB 'S' + $80 DEFW L0BFC ; 'link field' L0C0C: DEFB $03 ; 'name length field' L0C0D: DEFW L0EC3 ; 'code field' - docolon ; --- DEFW L086B ; DUP DEFW L0D94 ; pos DEFW L04B6 ; EXIT ; ------------- ; THE '0=' WORD ; ------------- ; (n -- flag) ; flag is 1 in n = 0. L0C15: DEFB '0' ; 'name field' DEFB '=' + $80 DEFW L0C0C ; 'link field' L0C19: DEFB $02 ; 'name length field' L0C1A: DEFW L0C1C ; 'code field' ; --- L0C1C: RST 18H ; pop word DE LD A,D ; test for OR E ; zero CP $01 ; sets carry if word is zero ; -> zero_or_one L0C21: LD A,$00 ; make accumulator zero. LD D,A ; set D to zero RLA ; pick up carry (1/0) LD E,A ; set DE to one or zero RST 10H ; push word DE JP (IY) ; to 'next'. ; ------------- ; THE '0<' WORD ; ------------- ; (n -- flag) ; flag is 1 if n is negative L0C29: DEFB '0' ; 'name field' DEFB '<' + $80 DEFW L0C19 ; 'link field' L0C2D: DEFB $02 ; 'name length field' L0C2E: DEFW L0C30 ; 'code field' ; --- L0C30: RST 18H ; pop word DE RL D ; test the sign bit. JR L0C21 ; back to above routine to stack the ; carry as one (true) or zero (false). ; ------------- ; THE '0>' WORD ; ------------- ; (n -- flag) ; flag is 1 if n is positive. L0C35: DEFB '0' ; 'name field' DEFB '>' + $80 DEFW L0C2D ; 'link field' L0C39: DEFB $02 ; 'name length field' L0C3A: DEFW L0C3C ; 'code field' ; --- L0C3C: RST 18H ; pop word DE LD A,D OR E JR Z,L0C21 ; to stack word one or zero RL D CCF JR L0C21 ; to stack word one or zero ; ------------ ; THE '=' WORD ; ------------ ; (n1, n2 -- flag) ; flag is 1 if n1=n2. L0C46: DEFB '=' + $80 ; 'name field' DEFW L0C39 ; 'link field' L0C49: DEFB $01 ; 'name length field' L0C4A: DEFW L0EC3 ; 'code field' - docolon ; --- L0C4C: DEFW L0DE1 ; - DEFW L0C1A ; 0= DEFW L04B6 ; exit ; ------------ ; THE '>' WORD ; ------------ ; (n1, n2 -- flag) ; flag is 1 if n1>n2. L0C52: DEFB '>' + $80 ; 'name field' DEFW L0C49 ; 'link field' L0C55: DEFB $01 ; 'name length field' L0C56: DEFW L0C58 ; 'code field' ; --- L0C58: RST 18H ; pop word DE PUSH DE ; RST 18H ; pop word DE POP HL ; CALL L0C99 ; JR L0C21 ; to stack word one or zero ; ------------ ; THE '<' WORD ; ------------ ; (n1, n2 -- flag) ; flag is 1 if n1 < n2. L0C61: DEFB '<' + $80 ; 'name field' DEFW L0C55 ; 'link field' L0C64: DEFB $01 ; 'name length field' L0C65: DEFW L0EC3 ; 'code field' - docolon ; --- DEFW L0885 ; swap DEFW L0C56 ; > DEFW L04B6 ; exit ; ------------- ; THE 'U<' WORD ; ------------- ; (un1, un2 -- flag) ; The flag is 1 if, of the two unsigned single length integers, un1 is less ; than un2. L0C6D: DEFB 'U' ; 'name field' DEFB '<' + $80 DEFW L0C64 ; 'link field' L0C71: DEFB $02 ; 'name length field' L0C72: DEFW L0C74 ; 'code field' ; --- L0C74: CALL L084E ; stk_to_bc L0C77: RST 18H ; pop word DE EX DE,HL AND A SBC HL,BC JR L0C21 ; to stack word one or zero ; ------------- ; THE 'D<' WORD ; ------------- ; (d1, d2 -- flag) ; flag is 1 if the signed double integer, d1 < d2. L0C7E: DEFB 'D' ; 'name field' DEFB '<' + $80 DEFW L0C71 ; 'link field' L0C82: DEFB $02 ; 'name length field' L0C83: DEFW L0C85 ; 'code field' ; --- L0C85: RST 18H ; pop word DE PUSH DE CALL L084E ; stk_to_bc RST 18H ; pop word DE POP HL AND A SBC HL,DE JR Z,L0C77 ; ADD HL,DE EX DE,HL CALL L0C99 ; RST 18H ; pop word DE JR L0C21 ; to stack word one or zero ; --- ; THE 'sign?' SUBROUTINE ; --- L0C99: LD A,H XOR D JP M,L0CA0 ; SBC HL,DE L0CA0: RL H RET ; ------------- ; THE 'U*' WORD ; ------------- ; (un1, un2 -- double length(un1 * un2)) ; Multiplies two unsigned single length integers to give an unsigned ; double length product. L0CA3: DEFB 'U' ; 'name field' DEFB '*' + $80 DEFW L0C82 ; 'link field' L0CA7: DEFB $02 ; 'name length field' L0CA8: DEFW L0CAA ; 'code field' ; => mult L0CAA: RST 18H ; pop word DE CALL L084E ; stk_to_bc LD HL,$0000 LD A,$10 L0CB3: ADD HL,HL EX DE,HL ADC HL,HL EX DE,HL JR NC,L0CBE ; ADD HL,BC JR NC,L0CBE ; INC DE L0CBE: DEC A JR NZ,L0CB3 ; EX DE,HL JR L0CF3 ; ; --- ; The 'div?' Internal Word ; --- L0CC4: DEFW L0CC6 L0CC6: RST 18H ; pop word DE EXX RST 18H ; pop word DE PUSH DE RST 18H ; pop word DE POP HL LD A,H OR L LD A,$21 ; 33 JR NZ,L0CD5 ; EX DE,HL LD A,$11 ; 17 L0CD5: EXX LD B,A XOR A LD H,A LD L,A LD C,A L0CDB: ADC HL,HL SBC A,A AND A SBC HL,DE SBC A,C JR NC,L0CE5 ; ADD HL,DE L0CE5: CCF EXX EX DE,HL ADC HL,HL EX DE,HL ADC HL,HL EXX DJNZ L0CDB ; EX DE,HL RST 10H ; push word DE EXX L0CF3: PUSH HL RST 10H ; push word DE POP DE RST 10H ; push word DE JP (IY) ; to 'next'. ; --------------- ; THE '/MOD' WORD ; --------------- ; (n1, n2 -- remainder, quotient of n1/n2) ; The remainder has the same sign as the dividend n1. L0CF9: DEFM "/MO" ; 'name field' DEFB 'D' + $80 DEFW L0CA7 ; 'link field' L0CFF: DEFB $04 ; 'name length field' L0D00: DEFW L0EC3 ; 'code field' - docolon ; --- L0D02: DEFW L0885 ; swap DEFW L08D2 ; >R DEFW L12E9 ; I DEFW L0C0D ; abs DEFW L104B ; stk_data DEFB $00 ; zero ; -> L0D0D: DEFW L08FF ; rot DEFW L086B ; dup DEFW L12E9 ; I DEFW L0E60 ; xor DEFW L08D2 ; >R DEFW L0C0D ; abs DEFW L0D8C ; U/MOD DEFW L08DF ; >R DEFW L0D94 ; pos DEFW L0885 ; swap DEFW L08DF ; >R DEFW L0D94 ; pos DEFW L0885 ; swap DEFW L04B6 ; exit ; ---------------- ; THE '*/MOD' WORD ; ---------------- ; (n1, n2, n3 -- remainder, quotient of (n1 * n2)/n3) ; As in */, n1 * n2 is held to double length. L0D29: DEFM "*/MO" ; 'name field' DEFB 'D' + $80 DEFW L0CFF ; 'link field' L0D30: DEFB $05 ; 'name length field' L0D31: DEFW L0EC3 ; 'code field' - docolon ; --- DEFW L08FF ; rot DEFW L08D2 ; >R DEFW L12E9 ; I DEFW L0C0D ; abs DEFW L08FF ; rot DEFW L086B ; dup DEFW L08DF ; >R DEFW L0E60 ; xor DEFW L08D2 ; >R DEFW L0C0D ; abs DEFW L0CA8 ; u* DEFW L1276 ; branch L0D4B: DEFW $FFC1 ; back to L0D0D (in /MOD) ; ------------ ; THE '/' WORD ; ------------ ; (n1, n2 -- n1/n2) ; Single length signed integer division. L0D4D: DEFB '/' + $80 ; 'name field' DEFW L0D30 ; 'link field' L0D50: DEFB $01 ; 'name length field' L0D51: DEFW L0EC3 ; 'code field' - docolon ; --- L0D53: DEFW L0D00 ; /MOD DEFW L0885 ; swap DEFW L0879 ; drop DEFW L04B6 ; exit ; -------------- ; THE 'MOD' WORD ; -------------- ; (n1, n2 -- remainder n1/n2) ; The remainder has the same sign as the dividend. L0D5B: DEFM "MO" ; 'name field' DEFB 'D' + $80 DEFW L0D50 ; 'link field' L0D60: DEFB $03 ; 'name length field' L0D61: DEFW L0EC3 ; 'code field' - docolon ; --- DEFW L0D00 ; /MOD DEFW L0879 ; drop DEFW L04B6 ; exit ; ------------ ; THE '*' WORD ; ------------ ; (n1, n2 -- n1*n2) L0D69: DEFB '*' + $80 ; 'name field' DEFW L0D60 ; 'link field' L0D6C: DEFB $01 ; 'name length field' DEFW L0EC3 ; 'code field' - docolon ; --- DEFW L0CA8 ; u* DEFW L0879 ; drop DEFW L04B6 ; exit ; ------------- ; THE '*/' WORD ; ------------- ; (n1, n2, n3 -- (n1*n2)/n3) ; The intermediate product n1*n2 is held to double length. L0D75: DEFB '*' ; 'name field' DEFB '/' + $80 DEFW L0D6C ; 'link field' L0D79: DEFB $02 ; 'name length field' L0D7A: DEFW L0EC3 ; 'code field' - docolon ; --- DEFW L0D31 ; */MOD DEFW L0885 ; swap DEFW L0879 ; drop DEFW L04B6 ; exit ; -------------- ; THE 'U/MOD' WORD ; -------------- ; (ud1, un2 -- un3, un4) ; In unsigned arithmetic throughout, divides the double length integer ud1 ; by the single length integer un2 to give a single length remainder un3 ; and a single length quotient un4. L0D84: DEFM "U/MO" ; 'name field' DEFB 'D' + $80 DEFW L0D79 ; 'link field' L0D8B: DEFB $05 ; 'name length field' L0D8C: DEFW L0EC3 ; 'code field' - docolon ; --- L0D8E: DEFW L0CC4 ; div? DEFW L0879 ; drop DEFW L04B6 ; exit ; --- ; make positive L0D94: DEFW L0EC3 ; 'code field' - docolon ; --- L0D96: DEFW L0C2E ; 0< DEFW L1283 ; ?branch (if false) L0D9A: DEFW $0003 ; to L0D9E DEFW L0DA9 ; negate L0D9E: DEFW L04B6 ; exit ; ----------------- ; THE 'NEGATE' WORD ; ----------------- ; (n -- -n) L0DA0: DEFM "NEGAT" ; 'name field' DEFB 'E' +$80 DEFW L0D8B ; 'link field' L0DA8: DEFB $06 ; 'name length field' L0DA9: DEFW L0DAB ; 'code field' ; --- L0DAB: LD BC,$0002 ; JR L0DBF ; ; ------------------ ; THE 'DNEGATE' WORD ; ------------------ ; (d -- -d) ; Double length integer negation. L0DB0: DEFM "DNEGAT" ; 'name field' DEFB 'E' +$80 DEFW L0DA8 ; 'link field' L0DB9: DEFB $07 ; 'name length field' L0DBA: DEFW L0DBC ; 'code field' ; --- L0DBC: LD BC,$0004 ; NEGATE joins here with bc=2 L0DBF: LD HL,($3C3B) ; SPARE AND A SBC HL,BC L0DC5: LD A,B SBC A,(HL) LD (HL),A INC HL DEC C JR NZ,L0DC5 ; JP (IY) ; to 'next'. ; ------------ ; THE '+' WORD ; ------------ ; (n1, n2 -- n1 + n2) L0DCE: DEFB '+' + $80 ; 'name field' DEFW L0DB9 ; 'link field' L0DD1: DEFB $01 ; 'name length field' L0DD2: DEFW L0DD4 ; 'code field' ; --- L0DD4: RST 18H ; pop word DE PUSH DE ; save on machine stack RST 18H ; pop word DE POP HL ; first number to HL ADD HL,DE ; the actual addition EX DE,HL ; result to DE RST 10H ; push word DE JP (IY) ; to 'next'. ; ------------ ; THE '-' WORD ; ------------ ; (n1, n2 -- n1-n2) ; flip the sign and do a plus. L0DDD: DEFB '-' + $80 ; 'name field' DEFW L0DD1 ; 'link field' L0DE0: DEFB $01 ; 'name length field' L0DE1: DEFW L0EC3 ; 'code field' - docolon ; --- L0DE3: DEFW L0DA9 ; negate DEFW L0DD2 ; + DEFW L04B6 ; exit ; ------------- ; THE 'D+' WORD ; ------------- ; (d1, d2 -- d1 + d2) ; double length integer addition. L0DE9: DEFB 'D' ; 'name field' DEFB '+' + $80 DEFW L0DE0 ; 'link field' L0DED: DEFB $02 ; 'name length field' L0DEE: DEFW L0DF0 ; 'code field' ; --- L0DF0: RST 18H ; pop word DE PUSH DE CALL L084E ; stk_to_bc RST 18H ; pop word DE PUSH DE RST 18H ; pop word DE EX DE,HL ADD HL,BC EX DE,HL RST 10H ; push word DE POP BC POP HL ADC HL,BC EX DE,HL RST 10H ; push word DE JP (IY) ; to 'next'. ; ------------- ; THE '1+' WORD ; ------------- ; (n -- n+1) L0E04: DEFB '1' ; 'name field' DEFB '+' + $80 DEFW L0DED ; 'link field' L0E08: DEFB $02 ; 'name length field' L0E09: DEFW L0E0B ; 'code field' ; --- L0E0B: RST 18H ; get word 'n' in DE JR L0E17 ; forward to increment and stack ; ------------- ; THE '2+' WORD ; ------------- ; (n -- n+2) L0E0E: DEFB '2' ; 'name field' DEFB '+' + $80 DEFW L0E08 ; 'link field' L0E12: DEFB $02 ; 'name length field' L0E13: DEFW L0E15 ; 'code field' ; --- L0E15: RST 18H ; get word 'n' in DE. INC DE ; increment n (4) ; -> L0E17: INC DE ; increment n (4) JR L0E2E ; forward to push word DE and exit ; ------------- ; THE '1-' WORD ; ------------- ; (n -- n-1) L0E1A: DEFB '1' ; 'name field' DEFB '-' + $80 DEFW L0E12 ; 'link field' L0E1E: DEFB $02 ; 'name length field' L0E1F: DEFW L0E21 ; 'code field' ; --- L0E21: RST 18H ; JR L0E2D ; ; ------------- ; THE '2-' WORD ; ------------- ; (n -- n-2) L0E24: DEFB '2' ; 'name field' L0E25: DEFB '-' + $80 L0E26: DEFW L0E1E ; 'link field' L0E28: DEFB $02 ; 'name length field' L0E29: DEFW L0E2B ; 'code field' ; --- ; L0E2B: RST 18H DEC DE ; -> L0E2D: DEC DE ; -> L0E2E: RST 10H ; push word DE JP (IY) ; to 'next'. ; ------------- ; THE 'OR' WORD ; ------------- ; (n1, n2 -- n1 OR n2) ; Bitwise Boolean operation. L0E31: DEFB 'O' ; 'name field' DEFB 'R' + $80 DEFW L0E28 ; 'link field' L0E35: DEFB $02 ; 'name length field' L0E36: DEFW L0E38 ; 'code field' ; --- L0E38: RST 18H ; pop word DE CALL L084E ; stk_to_bc LD A,E ; OR C ; OR low order bytes LD E,A ; LD A,D ; OR B ; OR high order bytes LD D,A ; RST 10H ; push word DE JP (IY) ; to 'next'. ; -------------- ; THE 'AND' WORD ; -------------- ; (n1, n2 -- n1 AND n2) ; Bitwise Boolean operation. L0E45: DEFM "AN" ; 'name field' DEFB 'D' + $80 DEFW L0E35 ; 'link field' L0E4A: DEFB $03 ; 'name length field' DEFW L0E4D ; 'code field' ; --- L0E4D: RST 18H CALL L084E ; stk_to_bc LD A,E ; AND C ; LD E,A ; LD A,D ; AND B ; LD D,A ; RST 10H ; push word DE JP (IY) ; to 'next'. ; -------------- ; THE 'XOR' WORD ; -------------- ; (n1, n2 -- n1 XOR n2) ; Bitwise Boolean XOR (exclusive or) L0E5A: DEFM "XO" ; 'name field' DEFB 'R' + $80 DEFW L0E4A ; 'link field' L0E5F: DEFB $03 ; 'name length field' L0E60: DEFW L0E62 ; 'code field' ; --- L0E62: RST 18H CALL L084E ; stk_to_bc LD A,E ; XOR C ; LD E,A ; LD A,D ; XOR B ; LD D,A ; RST 10H ; push word DE JP (IY) ; to 'next'. ; -------------- ; THE 'MAX' WORD ; -------------- ; (n1, n2 -- max (n1, n2)) ; Calculates the larger of two numbers. L0E72: DEFM "MA" ; 'name field' DEFB 'X' + $80 DEFW L0E5F ; 'link field' L0E74: DEFB $03 ; 'name length field' L0E75: DEFW L0EC3 ; 'code field' - docolon ; --- L0E77: DEFW L0912 ; over DEFW L0912 ; over DEFW L0C65 ; < DEFW L1271 ; branch L0E7F: DEFW $000F ; forward to L0E8F ; -------------- ; THE 'MIN' WORD ; -------------- ; (n1, n2 -- min (n1, n2)) ; Calculates the smaller of two numbers. L0E81: DEFM "MI" ; 'name field' DEFB 'N' + $80 DEFW L0E74 ; 'link field' L0E86: DEFB $03 ; 'name length field' DEFW L0EC3 ; 'code field' - docolon ; --- L0E89: DEFW L0912 ; over DEFW L0912 ; over DEFW L0C56 ; > ; -> L0E8F: DEFW L1283 ; ?branch L0E91: DEFW $0003 ; forward to L0995 DEFW L0885 ; swap L0995: DEFW L0879 ; drop DEFW L04B6 ; exit ; ------------------ ; THE 'DECIMAL' WORD ; ------------------ ; ( -- ) ; Sets the system number base to ten. L0E99: DEFM "DECIMA" ; 'name field' DEFB 'L' + $80 DEFW L0E86 ; 'link field' L0EA2: DEFB $07 ; 'name length field' DEFW L0EA5 ; 'code field' ; --- L0EA5: LD (IX+$3F),$0A ; update system variable BASE to 10 JP (IY) ; to 'next'. ; ------------ ; THE ':' WORD ; ------------ ; Introduces colon definitions. L0EAB: DEFB ':' + $80 ; 'name field' DEFW L0EA2 ; 'link field' L0EAE: DEFB $01 ; 'name length field' L0EAF: DEFW L1085 ; 'code field' - create and enclose ; --- L0EB1: DEFW L0EC3 ; do_colon DEFW L104B ; stk_data DEFB $0A ; ten marker byte? ; -> L0EB6: DEFW L1A0E ; end_forth L0EB8: LD HL,$3C3E ; FLAGS LD A,(HL) ; update bits 6 and 2. OR $44 ; signal in compile mode, definition ; incomplete. LD (HL),A ; update FLAGS. JP (IY) ; to 'next'. ; --- x0EC1 DEFB $E9 ;; x0Ec2 DEFB $FF ;; 0ec2 + ffe9 = 0eab = ':' ; ------------------------------- ; THE 'ENTER' or 'DOCOLON' action ; ------------------------------- ; L0EC3: EX DE,HL ; JP L04BA ; ; ----------------- ; THE 'CREATE' WORD ; ----------------- ; CREATE name ; ( -- ) ; Defines a new word with a header and an empty parameter field. ; When executed, the new word stacks its parameter field address. L0EC7: DEFM "CREAT" ; 'name field' DEFB 'E' + $80 DEFW L0EAE ; 'link field' L0ECF: DEFB $06 ; 'name length field' L0ED0: DEFW L0EC3 ; 'code field' - docolon ; --- L0ED2: DEFW L104B ; stk_data DEFB $20 ; a space delimiter DEFW L05AB ; word to pad DEFW L0EFB ; get-name in dict DEFW L0688 ; stk-zero link DEFW L0F4E ; , DEFW L0480 ; current DEFW L08B3 ; @ DEFW L086B ; dup DEFW L08B3 ; @ DEFW L0F4E ; , DEFW L0460 ; here DEFW L0885 ; swap DEFW L08C1 ; ! DEFW L0499 ; pad DEFW L0896 ; C@ fetch 1 byte DEFW L0F5F ; C, DEFW L1011 ; stack next word DEFW $0FEC ; ??? DEFW L0F4E ; , L0EF9: DEFW L04B6 ; exit ; ---------------------------- ; The 'get_name' Internal Word ; ---------------------------- ; Used only by the above CREATE thread. L0EFB: DEFW L0EFD ; headerless 'code field' ; --- L0EFD: CALL L0F2E ; blank stack RST 18H ; pop word DE LD A,(DE) DEC A ; zero becomes $FF CP $3F ; max length is 64 JR C,L0F09 ; forward if n range 1 - 64. RST 20H ; Error 6 DEFB $06 ; Name of new word too short or long. ; --- L0F09: ADD A,$08 ; allow for prev/len/addr 3 missing LD C,A ; LD B,$00 ; length to BC L0F0E: CALL L0F8C ; check free memory. x0f11 LD A,(DE) ; true length to A LD C,A ; and BC again LD HL,($3C37) ; STKBOT PUSH DE ; CALL L0F9E ; routine MAKE ROOM POP DE ; LD A,(DE) ; length of word in pad LD B,A ; transfer to counter. L0F1D: INC DE ; increase source LD A,(DE) ; fetch character CALL L0807 ; to_upper makes uppercase. LD (HL),A ; store in dictionary INC HL ; increase destination DJNZ L0F1D ; loop back for all letters. LD ($3C39),HL ; store this location in SPARE DEC HL ; step back to last letter of word. SET 7,(HL) ; and 'invert' it. JP (IY) ; to 'next'. ; --- L0F2E: BIT 2,(IX+$3E) ; test FLAGS incomplete definition ? JR Z,L0F36 ; forward if not. RST 20H ; Error 12 DEFB $0C ; Incomplete definition in dictionary. ; --- L0F36: LD HL,($3C37) ; fetch STKBOT LD DE,($3C39) ; fetch SPARE XOR A ; clear accumulator and carry flag SBC HL,DE ; subtract EX DE,HL ; LD (HL),E ; place low byte at next STACK slot. INC HL ; LD (HL),D ; place high byte LD H,A ; make HL zero LD L,A ; LD ($3C39),HL ; update system variable SPARE to zero RET ; return ; --------------------- ; ------------ ; THE ',' WORD ; ------------ ; ( n -- ) ; Encloses the single length integer in the dictionary. L0F4A: DEFB ',' + $80 ; 'name field' DEFW L0ECF ; 'link field' L0F4D: DEFB $01 ; 'name length field' L0F4E: DEFW L0EC3 ; 'code field' - docolon ; --- L0F50: DEFW L0F83 ; allot2 DEFW L0460 ; here DEFW L0E29 ; 2- DEFW L08C1 ; ! DEFW L04B6 ; exit ; ------------- ; THE 'C,' WORD ; ------------- ; ( n -- ) ; Encloses the less significant byte of n in the dictionary. L0F5A: DEFB 'C' ; 'name field' DEFB ',' + $80 DEFW L0F4D ; 'link field' L0F5E: DEFB $02 ; 'name length field' L0F5F: DEFW L0EC3 ; 'code field' - docolon ; --- L0F61: DEFW L104B ; stk-data DEFB $01 ; one DEFW L0F76 ; allot x0f66 DEFW L0460 ; here DEFW L0E1F ; 1- DEFW L08A5 ; C! DEFW L04B6 ; exit ; ---------------- ; THE 'ALLOT' WORD ; ---------------- ; (n -- ) ; Encloses n bytes in the dictionary, without initializing them. L0F6E: DEFM "ALLO" ; 'name field' DEFB 'T' + $80 DEFW L0F5E ; 'link field' L0F75: DEFB $05 ; 'name length field' L0F76: DEFW L0F78 ; 'code field' ; --- L0F78: CALL L084E ; stk_to_bc LD HL,($3C37) ; STKBOT CALL L0F9E ; routine MAKE ROOM JP (IY) ; to 'next'. ; -------------------------- ; The 'allot2' Internal Word ; -------------------------- ; Encloses 2 bytes in the dictionary, without initializing them. L0F83: DEFW L0EC3 ; headerless 'code field' - docolon ; --- L0F85: DEFW L104B ; stk_data DEFB $02 ; two bytes required DEFW L0F76 ; allot DEFW L04B6 ; exit ; ---------------------------------- ; THE 'DEFAULT MEMORY CHECK' ROUTINE ; ---------------------------------- ; called each cycle in slow mode to check free memory. L0F8C: LD HL,$001E ; Allow a thirty byte overhead. ; ---------------------------------- ; THE 'CHECK FREE MEMORY' SUBROUTINE ; ---------------------------------- L0F8F: PUSH BC ; save bytes to check. ADD HL,BC ; LD BC,($3C3B) ; SPARE ADD HL,BC ; carry indicates error - past 65535 POP BC ; restore number of bytes JR C,L0F9C ; forward with error SBC HL,SP ; now check against the return stack ; (machine stack) RET C ; return if value is less L0F9C: RST 20H ; Error 1 DEFB $01 ; Not enough memory ; -------------------------- ; THE 'MAKE ROOM' SUBROUTINE ; -------------------------- L0F9E: EX DE,HL ; first new location to DE LD HL,$0028 ; overhead 40 bytes. L0FA2: CALL L0F8F ; check free memory. ; now increase the two data stack pointers. LD HL,($3C37) ; fetch value of STKBOT ADD HL,BC ; add required room. LD ($3C37),HL ; update STKBOT. LD HL,($3C3B) ; fetch value of SPARE PUSH HL ; take a copy of 'old' value ADD HL,BC ; add required room. LD ($3C3B),HL ; update SPARE. EX (SP),HL ; new SPARE value to stack, ; old SPARE value to HL. PUSH HL ; push old SPARE value. AND A ; clear carry. SBC HL,DE ; get length of stack and 12 LD B,H ; LD C,L ; POP HL ; old spare POP DE ; new spare RET Z ; return if same. ; else new SPARE must be higher than old spare. DEC HL ; point to end of data stack DEC DE ; adjust destination. LDDR ; copy the Data Stack + gap upwards. L0FC2: INC HL ; point to first new location. RET ; return. ; ------------------- ; THE 'VARIABLE' WORD ; ------------------- ; VARIABLE name ; (n -- ) ; Sets up a variable with the given name, and initializes its value to n. L0FC4: DEFM "VARIABL" ; 'name field' DEFB 'E' + $80 DEFW L0F75 ; 'link field' L0FCE: DEFB $08 ; 'name length field' DEFW L1085 ; 'code field' - create and enclose ; --- L0FD1: DEFW L0FF0 ; push word DE DEFW L0F4E ; , DEFW L04B6 ; exit ; ------------------- ; THE 'CONSTANT' WORD ; ------------------- ; CONSTANT name ; (n -- ) ; Defines a constant with the given name and value n. L0FD7: DEFM "CONSTAN" ; 'name field' DEFB 'T' + $80 DEFW L0FCE ; 'link field' L0FE1: DEFB $08 ; 'name length field' L0FE2: DEFW L1085 ; 'code field' - create and enclose ; --- L0FE4: DEFW L0FF5 ; pad?? DEFW L0F4E ; , DEFW L04B6 ; exit ; --- ; ??? x0fea DEFB $DC ;; x0feb DEFB $FE ;; 0feb + fedc = 0Ec7 = CREATE ; -> L0FEC: JR L0FF0 ; skip forward x0fee DEFB $D5 ;; x0fef DEFB $FF ;; 0fef + ffd5 = 0fc4 = VARIABLE ; --- L0FF0: RST 10H ; push word DE JP (IY) ; to 'next'. ; --- x0FF3 DEFB $E3 ;; x0ff4 DEFB $FF ;; 0ff4 + ffe3 = 0fd7 = CONSTANT ; --> pad L0FF5: EX DE,HL LD E,(HL) INC HL LD D,(HL) RST 10H ; push word DE JP (IY) ; to 'next'. ; ------------------ ; THE 'LITERAL' WORD ; ------------------ ; (n -- ) ; Compiles the top of the stack into a word definition as a literal. ; Compiles integers. decimal 4102 = $1006. c.f. $1055 L0FFC: DEFM "LITERA" ; 'name field' DEFB 'L' + $80 DEFW L0FE1 ; 'link field' L1005: DEFB $47 ; 'name length field' L1006: DEFW L1108 ; 'code field' - compile ; --- L1008: DEFW L1011 ; stack next word DEFW L0F4E ; , DEFW L04B6 ; exit ; --- x100E: DEFB $02 ;; x100f DEFB $FF ;; 100f + ff02 = 0f11 nah! x1010 DEFB $FF ;; ; ----------------------------------- ; The 'Stack Next Word' Internal Word ; ----------------------------------- L1011: DEFW L1013 ; headerless 'code field' ; --- L1013: LD B,$01 ; counter - one word to push L1015: POP HL ; drop the 'Next Word' pointer. LD E,(HL) ; low byte to E. INC HL ; increment pointer. LD D,(HL) ; high byte to D. ; -> E B=1 (one byte op) L1019: INC HL ; increment the 'Next Word' pointer L101A: PUSH HL ; the 'Next Word' pointer goes to ; the Return Stack. RST 10H ; stack Data Word DE DJNZ L1015 ; loop back if more than one. L101E: JP (IY) ; to 'next'. ; ---------------- ; THE 'ASCII' WORD ; ---------------- ; Takes the next word from the input buffer, and yields the ASCII code ; of its first character. If compiling, then compiles this as a literal. ; ; e.g. :STARS 0 DO ASCII * EMIT LOOP ; ; (--ASCII code) (if interpreting) ; (--) (if compiling) L1020: DEFM "ASCI" ; 'name field' DEFB 'I' + $80 DEFW L1005 ; 'link field' L1027: DEFB $45 ; 'name length field' (immediate mode) L1029: DEFW L0EC3 ; 'code field' - docolon ; ---------------- L102A: DEFW L104B ; stk_data DEFB $20 ; space delimiter DEFW L05AB ; word to pad DEFW L0E09 ; 1+ DEFW L0896 ; C@ DEFW L1A0E ; end-forth. BIT 6,(IX+$3E) ; FLAGS JR Z,L101E ; back to a jp (iy) CALL L04B9 ; forth L103E: DEFW L1011 ; stack next word DEFW L104B ; (stk_data) DEFW L0F4E ; , DEFW L0F5F ; c, DEFW L04B6 ; exit ; --- x1048 DEFB $01 ;; ? x1049 DEFB $D6 ;; ? x104a DEFB $FF ;; ? 104a + ffd6 = 1020 = ASCII ; ---------------------------- ; The 'stk-data' Internal Word ; ---------------------------- ; used succinctly to stack the following byte as a word. L104B: DEFW L104D ; headerless 'code field' ; --- L104D: POP HL ; retrieve the 'Next Word' pointer. LD E,(HL) ; fetch the single byte from there. LD D,$00 ; set high order byte to zero. LD B,$01 ; set counter to 1. JR L1019 ; back to stack one word and ; put the incremented pointer back on ; the Return Stack. ; -------------------------- ; The 'stk_fp' Internal Word ; -------------------------- ; stack and enclose a floating point number - two words. L1055: DEFW L1108 ; headerless 'code field' - compile ; --- DEFW L1064 ; stack two words. DEFW L0885 ; swap DEFW L0F4E ; , DEFW L0F4E ; , DEFW L04B6 ; exit ; --- x1061 DEFB $04 ;; x1062 DEFB $FF ;; 1062 + ff04 = 0f66 XX x1063 DEFB $FF ;; ; ----------------------------------- ; The 'STACK TWO WORDS' Internal Word ; ----------------------------------- L1064: DEFW L1066 ; headerless 'code field' ; --- L1066: LD B,$02 ; set counter to two JR L1015 ; back to stack 2 words ; ----------------- ; THE 'DEFINER' WORD ; ----------------- ; Used with 'DOES>' to define new defining words. i.e. words that themselves ; define new words. ; The format is ; DEFINER name ; defining routine ; DOES> ; action routine ; ; ; name is the name of the new defining word; when executed it will set up ; the header of a new word and use its defining routine to set up the ; parameter field. When this new word in its turn is executed, its parameter ; field will be put on the stack and the action routine will be executed. L106A: DEFM "DEFINE" ; 'name field' DEFB 'R' + $80 DEFW L1027 ; 'link field' L1073: DEFB $07 ; 'name length field' L1074: DEFW L1085 ; 'code field' - create and enclose ; --- L1076: DEFW L1085 ; create and enclose DEFW L0460 ; here DEFW L104B ; stk-data DEFB $0C ; 12 marker byte DEFW L0F83 ; allot2 DEFW L1276 ; branch L1081: DEFW $FE34 ; back to L0EB6 ; --- x1083 DEFB $E6 ;; x1084 DEFB $FF ;; 1084 + ffe6 = 106a = DEFINER ; --- ;; createe and fill ; ---- ; used seven times as a code word. L1085: CALL L0FF0 ; push word DE (save addr nxt wrd on DS) DEFW L0ED0 ; create DEFW L086B ; dup DEFW L08B3 ; @ DEFW L0460 ; here DEFW L0E29 ; 2- DEFW L08C1 ; ! L1094: DEFW L0E13 ; 2+ DEFW L109A ; pop DE DEFW L04B6 ; exit ; ----------- ; pop word DE ; ----------- ; branch to addr on stack??? L109A: DEFW L109C ; headerless 'code field' ; --- L109C: RST 18H ; unstack Data Word DE JP L0EC3 ; start new thread. ; --------------- ; THE 'CALL' WORD ; --------------- ; (address -- ) ; Executes Z80 machine code at address on the stack. The code is terminated ; by a jp (iy) ; e.g. in hex ; DEFINER CODE DOES> CALL ; ; CODE EI FB C, FD C, E9 C, ; The word EI will enable interrupts. L10A0: DEFM "CAL" ; 'name field' DEFB 'L' + $80 DEFW L1073 ; 'link field' L10A6: DEFB $04 ; 'name length field' L10A7: DEFW L10A9 ; 'code field' ; --- L10A9: RST 18H EX DE,HL JP (HL) ; ---------------- ; THE 'DOES>' WORD ; ---------------- ; See DEFINER. L10AC: DEFM "DOES" ; 'name field' DEFB '>' + $80 DEFW L10F4 ; 'link field' L10B3: DEFB $45 ; 'name length field' (immediate mode) L10B4: DEFW L1108 ; 'code field' - compile L10B6: DEFW L10E8 ; exit DEFW L12D8 ; check?? DEFB $0C ; 12 DEFW L10CD ; DEFW L104B ; stk_data DEFB $CD ; data call ? DEFW L0F5F ; C, DEFW L1011 ; stack next word DEFW L0FF0 ; (push word DE) DEFW L0F4E ; , DEFW L104B ; stk-data DEFB $0A ; ten marker byte. DEFW L04B6 ; exit ; ----------------------- ; The '???' Internal Word ; ----------------------- L10CD: DEFW L0EC3 ; headerless 'code field' - docolon ; --- DEFW L086B ; dup DEFW L0E29 ; 2- DEFW L15B5 ; namefield DEFW L0460 ; here DEFW L0DE1 ; - DEFW L0E1F ; 1- DEFW L0F4E ; , DEFW L0460 ; here DEFW L0885 ; swap DEFW L08C1 ; ! DEFW L04B6 ; exit ; --- x10e5 DEFB $05 ;; x10e6 DEFB $C5 ;; x10e7 DEFB $FF ;; 10e7 + ffc5 = 10ac = DOES> ; --- L10E8: DEFW L04B8 ; exit? ; ------------------- ; THE 'COMPILER' WORD ; ------------------- ; Used with 'RUNS>' for defining new compiling words, i.e. words that are ; used within word definitions to give an immediate effect of compiling ; some information into the dictionary. ; (This is traditionally done with IMMEDIATE, but COMPILER...RUNS> works ; better with EDIT etc.) L10EA: DEFM "COMPILE" ; 'name field' DEFB 'R' + $80 DEFW L10A6 ; 'link field' L10F4: DEFB $08 ; 'name length field' L10F5: DEFW L1085 ; 'code field' - create and enclose ; --- DEFW L1108 ; compile DEFW L1160 ; immediate DEFW L0460 ; here DEFW L104B ; stk_data L10FF: DEFB $0B ; 11 marker byte DEFW L0F83 ; allot2 DEFW L1276 ; branch L1104: DEFW $FDB1 ; back to L0EB6 ; --- x1106 DEFB $E3 ;; x1107 DEFB $FF ;; 1107 + ffe3 = 10ea = COMPILER ; --------------------- ; THE 'COMPILE' ROUTINE ; --------------------- ; Instead of executing code words as they are encountered, lay them down in ; the dictionary along with any parameters. L1108: BIT 6,(IX+$3E) ; test FLAGS - compiler mode ? JR NZ,L1110 ; skip error if so. RST 20H ; Error 4. DEFB $04 ; Compiling word used in interpret mode. L1110: CALL L0FF0 ; push word DE (then jp (iy)) DEFW L086B ; dup DEFW L08B3 ; @ DEFW L0F4E ; , DEFW L1276 ; branch L111B: DEFW $FF78 ; to L1094 - definer code ; ---------------- ; THE 'RUNS>' WORD ; ---------------- ; See COMPILER L111D: DEFM "RUNS" ; 'name field' DEFB '>' + $80 DEFW L10B3 ; 'link field' L1124: DEFB $45 ; 'name length field' (immediate mode) L1125: DEFW L1108 ; 'code field' - compile ; --- L1127: DEFW L1140 ; vv DEFW L12D8 ; check-for DEFB $0B ; 11 marker byte. DEFW L0885 ; swap DEFW L0F5F ; c, DEFW L10CD ; ? DEFW L1011 ; stack next word DEFW L1142 DEFW L0F4E ; , DEFW L104B ; stk-data DEFB $0A ; ten. marker byte. DEFW L04B6 ; exit ; --- x113d DEFB $05 ;; x113e DEFB $DE ;; x113f DEFB $FF ;; 113f + ffde = 111d = RUNS> ; --- L1140: DEFW L04B8 L1142: POP HL PUSH DE EX DE,HL RST 10H ; push word DE LD B,D LD C,E POP DE PUSH DE DEC DE DEC DE CALL L159E ; POP DE PUSH BC JP L0EC3 ; ; -------------------- ; THE 'IMMEDIATE' WORD ; -------------------- ; ( -- ) ; The most recent word in the current vocabulary is made immediate, so that ; it will execute even in compile mode. L1154: DEFM "IMMEDIAT" ; 'name field' DEFB 'E' + $80 DEFW L1124 ; 'link field' L115F: DEFB $09 ; 'name length field' L1160: DEFW L0EC3 ; 'code field' - docolon ; --- L1162: DEFW L0480 ; current DEFW L08B3 ; @ DEFW L08B3 ; @ DEFW L1A0E ; end-forth. L116A: RST 18H ; pop word DE EX DE,HL SET 6,(HL) JP (IY) ; to 'next'. ; --------------------- ; THE 'VOCABULARY' WORD ; --------------------- ; ( -- ) ; Defines a new vocabulary with the given name. L1170: DEFM "VOCABULAR" ; 'name field' DEFB 'Y' + $80 DEFW L115F ; 'link field' L117C: DEFB $0A ; 'name length field' L117D: DEFW L1085 ; 'code field' - create and enclose ; --- L117F: DEFW L11B5 ; set context DEFW L0480 ; current DEFW L08B3 ; @ DEFW L0E13 ; 2+ DEFW L0F4E ; , DEFW L0688 ; stk-zero DEFW L0F5F ; C, DEFW L0460 ; here DEFW L1011 ; stack next word DEFW $3C35 ; (VOCLNK) DEFW L086B ; dup DEFW L08B3 ; @ DEFW L0F4E ; , DEFW L08C1 ; ! DEFW L04B6 ; exit ; ---------------------- ; THE 'DEFINITIONS' WORD ; ---------------------- ; ( -- ) ; The CONTEXT vocabulary is made the CURRENT vocabulary as well. L119D: DEFM "DEFINITION" ; 'name field' DEFB 'S' + $80 DEFW L117C ; 'link field' L11AA: DEFB $0B ; 'name length field' L11AB: DEFW L11AD ; 'code field' ; --- L11AD: LD HL,($3C33) ; CONTEXT LD ($3C31),HL ; CURRENT JP (IY) ; to 'next'. ; --- L11B5: LD ($3C33),DE ; CONTEXT JP (IY) ; to 'next'. ; --- ; ------------- ; THE 'IF' WORD ; ------------- ; (n -- ) ; Used in the form ; IF ... THEN ; or ; IF ... ELSE ... THEN ; In the first form, if n is non-zero then the words between IF and THEN ; are executed; otherwise they are skipped over. ; In the second form, if n is non-zero then the words between IF and ELSE ; are executed and those between ELSE and THEN are skipped over, while if ; n is zero then the words between IF and ELSE are skipped over and those ; between ELSE and THEN are executed. L11BB: DEFB 'I' ; 'name field' DEFB 'F' + $80 DEFW L13E0 ; 'link field' L11BF: DEFB $42 ; 'name length field' (immediate word) DEFW L1108 ; 'code field' - compile ; --- DEFW L1283 ; ?branch DEFW L0460 ; here DEFW L104B ; stk_data DEFB $02 ; 2 locations required for jump length DEFW L0F83 ; allot2 DEFW L04B6 ; exit ; ---------------- ; THE 'WHILE' WORD ; ---------------- ; (n -- ) ; Used in BEGIN ... WHILE ... REPEAT. If n = 0 then skips over to just past ; REPEAT. L11CD: DEFM "WHIL" ; 'name field' DEFB 'E' + $80 DEFW L11BF ; 'link field' L11D4: DEFB $45 ; 'name length field' (immediate mode) L11D5: DEFW L1108 ; 'code field' - compile ; --- DEFW L1288 ; ?branch DEFW L12D8 ; check-for DEFB $01 ; 1 DEFW L0460 ; here DEFW L104B ; stk-data DEFB $04 ; four DEFW L0F83 ; allot DEFW L04B6 ; exit ; --------------- ; THE 'ELSE' WORD ; --------------- ; ( -- ) ; Used with IF and THEN. L11E5: DEFM "ELS" ; 'name field' DEFB 'E' + $80 DEFW L11D4 ; 'link field' L11EB: DEFB $44 ; 'name length field' (immediate mode) L11EC: DEFW L1108 ; 'code field' - compile ; --- DEFW L1271 ; branch DEFW L12D8 ; check-for DEFB $02 ; two DEFW L0F83 ; allot2 DEFW L1225 ; ? DEFW L0460 ; here DEFW L0E29 ; 2- DEFW L104B ; stk-data DEFB $02 ; two DEFW L04B6 ; exit ; --------------- ; THE 'THEN' WORD ; --------------- ; Used with IF. L1200: DEFM "THE" ; 'name field' DEFB 'N' + $80 DEFW L11EB ; 'link field' L1206: DEFB $44 ; 'name length field' (immediate mode) L1207: DEFW L1108 ; 'code field' - compile ; --- DEFW L12A4 ; end? DEFW L12D8 ; check-for DEFB $02 DEFW L1225 ; ? DEFW L04B6 ; exit ; --------------- ; THE 'BEGIN' WORD ; --------------- ; ( -- ) ; Used with either UNTIL or WHILE...REPEAT. L1212: DEFM "BEGI" ; 'name field' DEFB 'N' + $80 DEFW L1206 ; 'link field' L1219: DEFB $45 ; 'name length field' (immediate mode) L121A: DEFW L1108 ; 'code field' - compile ; --- DEFW L129F DEFW L0460 ; here DEFW L104B ; stk_data DEFB $01 ; 1 DEFW L04B6 ; exit ; ----------------------- ; The '???' Internal Word ; ----------------------- L1225: DEFW L0EC3 ; headerless 'code field' - docolon ; --- DEFW L086B ; dup DEFW L0460 ; here DEFW L0885 ; swap DEFW L0DE1 ; - DEFW L0E1F ; 1- DEFW L0885 ; swap DEFW L08C1 ; ! DEFW L04B6 ; exit ; ----------------------- ; The '???' Internal Word ; ----------------------- L1237: DEFW L0EC3 ; headerless 'code field' - docolon ; --- DEFW L0460 ; here DEFW L0DE1 ; - DEFW L0E1F ; 1- DEFW L0F4E ; , DEFW L04B6 ; exit ; ----------------- ; THE 'REPEAT' WORD ; ----------------- ; ( -- ) ; Used in construction BEGIN ... WHILE .. REPEAT. ; Causes a jump back to just after BEGIN. L1243: DEFM "REPEA" ; 'name field' DEFB 'T' + $80 DEFW L1219 ; 'link field' L124B: DEFB $46 ; 'name length field' (immediate mode) L124C: DEFW L1108 ; 'code field' - compile ; --- L124E DEFW L1276 ; branch L1250: DEFW L12D8 ; check_for DEFB $04 ; four DEFW L0885 ; swap DEFW L1237 ; ? DEFW L1225 ; ? DEFW L04B6 ; exit ; ---------------- ; THE 'UNTIL' WORD ; ---------------- ; (n -- ) ; Used in BEGIN ... UNTIL. ; Loops back to BEGIN if n = 0 L125B: DEFM "UNTI" ; 'name field' DEFB 'L' + $80 DEFW L124B ; 'link field' L1262: DEFB $45 ; 'name length field' (immediate mode) L1263: DEFW L1108 ; 'code field' - compile ; --- DEFW L128D ; ?branch DEFW L12D8 ; check_for DEFB $01 ; DEFW L1237 ; ? DEFW L04B6 ; exit ; --- x126E DEFB $02 ;; x126F DEFB $75 ;; x1270 DEFB $FF ;; 1270 + ff75 = 11e5 = ELSE ; --- L1271: DEFW L1278 ; ? ; --- x1273 DEFB $02 ;; x1274 DEFB $CE ;; x1275 DEFB $FF ;; 1275 + ffce = 1243 = REPEAT ; -------------------------- ; The 'branch' Internal Word ; -------------------------- L1276: DEFW L1278 ; headerless 'code field' ; --- L1278: POP HL ; drop next word pointer LD E,(HL) ; read the 16-bit offset INC HL ; that is LD D,(HL) ; stored there. L127C: ADD HL,DE ; add to current address. JP L04BA ; jump back into address loop so that ; a new address gets stacked as IP. ; --- x1280 DEFB $02 ;; x1281 DEFB $39 ;; x1282 DEFB $FF ;; 1282 + ff39 = 11bb = IF ; --- L1283: DEFW L128F ; from IF, convert, line, min, etc. ; --- x1285 DEFB $02 ;; x1286 DEFB $46 ;; x1287 DEFB $FF ;; 1287 + ff46 = 11cd = WHILE ; --- L1288: DEFW L128F ; from WHILE ; --- x128A DEFB $02 ;; x128B DEFB $CF ;; x128C DEFB $FF ;; 128c + ffcf = 125b = UNTIL ; --------------------------- ; The '?branch' Internal Word ; --------------------------- L128D: DEFW L128F ; headerless 'code field' ; --- L128F: CALL L084E ; stk_to_bc LD A,B ; test for OR C ; zero ; -> from +loop L1294: JR Z,L1278 ; make the jump to "branch" if zero. POP HL ; else drop the pointer. INC HL ; step over. INC HL ; the jump bytes JP L04BA ; jump back into address loop so that ; a new address gets stacked as IP. ; --- x129C DEFB $00 ;; x129D DEFB $74 ;; x129E DEFB $FF ;; 129e + ff74 = 1212 = BEGIN ; --- L129F: DEFW L04B9 ; forth ; --- x12A1 DEFB $00 ;; x12A2 DEFB $5D ;; x12A3 DEFB $FF ;; 12a3 + ff5d = 1200 = THEN ; --- L12A4: DEFW L04B9 ; ------------- ; THE 'DO' WORD ; ------------- ; (limit, initial value -- ) ; Sets up a DO loop, initializing the loop counter to the initial value. ; The limit and loop counter are stored on the return stack. ; See LOOP and +LOOP. L12A6: DEFB 'D' ; 'name field' DEFB 'O' + $80 DEFW L1262 ; 'link field' L12AA: DEFB $42 ; 'name length field' (immediate mode) L12AB: DEFW L1108 ; 'code field' - compile ; --- DEFW L1323 ; shuffle DEFW L0460 ; here DEFW L104B ; stk_data DEFB $03 ; 3 marker byte. DEFW L04B6 ; exit ; --------------- ; THE 'LOOP' WORD ; --------------- ; ( -- ) ; Like +LOOP (below) but the number added onto the loop counter is 1. L12B6: DEFM "LOO" ; 'name field' DEFB 'P' + $80 DEFW L12AA ; 'link field' L12BC: DEFB $44 ; 'name length field' (immediate mode) L12BD: DEFW L1108 ; 'code field' - compile ; --- DEFW L1332 ; shuffle more L12C1: DEFW L12D8 ; check-for DEFB $03 ; 3 marker byte DEFW L1237 ; ? DEFW L04B6 ; exit ; ---------------- ; THE '+LOOP' WORD ; ---------------- ; (n -- ) ; Used with DO. Adds n to the loop counter, and loops back if the loop counter ; is now less than the limit (if n >= 0) or greater than the limit (if n < 0). L12C8: DEFM "+LOO" ; 'name field' DEFB 'P' + $80 DEFW L12BC ; 'link field' L12CF: DEFB $45 ; 'name length field' (immediate mode) L12D0: DEFW L1108 ; 'code field' - compile ; --- L12D2: DEFW L133C ; ? DEFW L1276 ; branch L12D6: DEFW $FFEA ; back to L12C1 ; ----------------------------- ; The 'check-for' Internal Word ; ----------------------------- ; Checks for expected marker byte which indicates stack is balanced and that ; a previous mandatory word was present. L12D8: DEFW L12DA ; headerless 'code field' ; --- L12DA: RST 18H ; pop word DE POP HL ; LD A,(HL) ; INC HL ; PUSH HL ; SUB E ; OR D ; JR Z,L132D ; to next via jp (iy). ; else... RST 20H ; Error 5 DEFB $05 ; Word is not properly structured. ; ------------ ; THE 'I' WORD ; ------------ ; ( -- loop counter) ; Copies the top of the return stack to the data stack. This will be either ; the loop counter for the innermost DO...LOOP, or the number most recently ; transferred by >R. L12E5: DEFB 'I' + $80 ; 'name field' DEFW L11AA ; 'link field' L12E8: DEFB $01 ; 'name length field' L12E9: DEFW L12EB ; 'code field' ; --- L12EB: POP BC ; pop return address POP DE ; pop the loop counter to DE. PUSH DE ; now restore the stack PUSH BC ; exactly as it was. RST 10H ; push Data Word DE - inner loop counter JP (IY) ; to 'next'. ; ------------- ; THE 'I'' WORD ; ------------- ; ( -- limit) ; Copies the second number down on the return stack to the data stack ; (so in a DO loop it copies the limit of the loop). L12F2: DEFB 'I' ; 'name field' DEFB $A7 ; "'" + $80 DEFW L12E8 ; 'link field' L12F6: DEFB $02 ; 'name length field' L12F7: DEFW L12F9 ; 'code field' ; --- L12F9: LD HL,$0004 ; two bytes per entry. JR L1307 ; forward to use the 'J' indexing ; routine ; ------------ ; THE 'J' WORD ; ------------ ; ( -- loop counter) ; Copies the third entry on the return stack to the data stack. ; This will be either the loop counter for the second innermost DO loop ; or the number put on the return stack by the most recent >R. L12FE: DEFB 'J' + $80 ; 'name field' DEFW L12F6 ; 'link field' L1301: DEFB $01 ; 'name length field' L1302: DEFW L1304 ; 'code field' ; --- L1304: LD HL,$0006 ; two bytes per entry ; -> I' joins here with HL=4 L1307: ADD HL,SP ; index the stack pointer. LD E,(HL) ; low order byte to E INC HL ; address high byte. LD D,(HL) ; DE now holds a copy of the required ; entry from the Return Stack RST 10H ; stack Data Word DE JP (IY) ; to 'next'. ; ---------------- ; THE 'LEAVE' WORD ; ---------------- ; ( -- ) ; Forces termination of a DO loop at the next LOOP or +LOOP by setting the ; loop counter equal to the limit. L130E: DEFM "LEAV" ; 'name field' DEFB 'E' + $80 DEFW L1301 ; 'link field' L1315: DEFB $05 ; 'name length field' L1316: DEFW L1318 ; 'code field' ; --- L1318: POP BC ; pop return address to BC. POP HL ; pop the loop counter. POP HL ; now the limit. PUSH HL ; push unaltered limit. PUSH HL ; push counter - now limit. PUSH BC ; restore return address. JP (IY) ; to 'next'. ; --- x1320 DEFB $00 ;; x1321 DEFB $84 ;; x1322 DEFB $FF ;; 1322 + ff84 = 12a6 = DO ; ----------------------- ; The '???' Internal Word ; ----------------------- L1323: DEFW L1325 ; headerless 'code field' ; --- L1325: CALL L084E ; stk_to_bc RST 18H ; pop word DE POP HL PUSH DE L132B: PUSH BC PUSH HL L132D: JP (IY) ; to 'next'. ; --- x132F DEFB $02 ;; x1330 DEFB $85 ;; x1331 DEFB $FF ;; 1331 + ff85 = 12b6 = LOOP ; ----------------------- ; The '???' Internal Word ; ----------------------- L1332: DEFW L1334 ; headerless 'code field' ; --- L1334: LD DE,$0001 JR L133F ; forward => ; --- x1339 DEFB $02 x133A DEFB $8D x133B DEFB $FF ; ----------------------- ; The '???' Internal Word ; ----------------------- ; loop counter + n ; Note. ADC HL,DE is used in preference to ADD HL,DE as affects P/O flag L133C: DEFW L133E ; headerless 'code field' ; --- L133E: RST 18H ; pop word DE - number to be added (n) ; => L133F: POP BC ; pop return address to BC. POP HL ; loop counter to HL. AND A ; clear carry. ADC HL,DE ; add the number specified. LD A,D ; save MSB of (n) in A. POP DE ; now pop the limit to DE. SCF ; set carry. JP PE,L1358 ; jump forward with overflow. PUSH DE ; push limit PUSH HL ; push adjusted counter. RLCA ; now test sign of number (n) JR NC,L1350 ; EX DE,HL L1350: CALL L0C99 ; CCF JR NC,L1358 ; POP HL POP HL L1358: PUSH BC SBC A,A JP L1294 ; jump to branch on zero. ; ------------ ; THE '(' WORD ; ------------ ; Starts a comment terminated by ')' L135D: DEFB '(' + $80 ; 'name field' DEFW L13D4 ; 'link field' L1360: DEFB $41 ; 'name length field' (immediate mode) L1361: DEFW L1108 ; 'code field' - compile ; --- L1363: DEFW L1379 ; DEFW L104B ; stk_data DEFB $29 ; character ')' - delimiter L1368: DEFW L0460 ; here DEFW L0885 ; swap DEFW L0F83 ; allot2 DEFW L139F ; find) DEFW L0885 ; swap DEFW L08C1 ; ! DEFW L04B6 ; exit ; --- x1376 DEFB $FF ;; x1377 DEFB $E5 ;; x1378 DEFB $FF ;; 1378 + ffe5 = 135d = '(' ; ----------------------- ; The '???' Internal Word ; ----------------------- L1379: DEFW L137B ; headerless 'code field' ; --- L137B: POP HL LD E,(HL) INC HL LD D,(HL) INC DE JP L127C ; ; ------------- ; THE '."' WORD ; ------------- ; ( -- ) ; Prints the following string terminated by ". L1383: DEFB '.' ; 'name field' DEFB '"' + $80 DEFW L1360 ; 'link field' L1387: DEFB $42 ; 'name length field' (immediate mode) L1388: DEFW L1108 ; 'code field' - compile ; --- L138A: DEFW L1396 ; pr_embedded string. DEFW L104B ; stk_data DEFB $22 ; '"' - delimiter DEFW L1276 ; branch L1391: DEFW $FFD6 ; back to 1368 (1392+$FFD6) ; same routine as for matching comments ; --- x1393 DEFB $FF ;; x1394 DEFB $EE ;; x1395 DEFB $FF ;; 1395 + ffee = 1383 = ." ; ----------------------- ; The '???' Internal Word ; ----------------------- ; print string embedded in Dictionary L1396: DEFW L1398 ; headerless 'code field' ; --- L1398: POP DE CALL L0979 ; pr_string1 PUSH DE JP (IY) ; to 'next'. ; ----------------------- ; The '???' Internal Word ; ----------------------- ; enclose comment ; comments may be multiple ; e.g. : SV ( system) ( variables) CLS BEGIN 0 0 AT 15360 80 TYPE 0 UNTIL ; L139F: DEFW L13A1 ; headerless 'code field' ; --- L13A1: RST 18H ; pop word DE PUSH DE ; save delimiter. CALL L05E1 ; find the ')' delimiter LD H,D LD L,E ADD HL,BC LD A,(HL) POP HL ; pop the delimiter. CP L JR Z,L13B8 ; forward with a match. =-> EX DE,HL ; RST 10H ; push word DE LD DE,$0578 ; addr retype? CALL L1815 ; pr2 JR L13A1 ; loop back ; --- ; =-> L13B8: PUSH DE PUSH BC LD HL,($3C37) ; STKBOT CALL L0F9E ; routine MAKE ROOM POP BC POP DE PUSH DE PUSH BC EX DE,HL LDIR ; copy comment to dictionary. POP BC LD D,B LD E,C RST 10H ; push word DE POP DE CALL L07DA ; JP (IY) ; to 'next'. ; ------------ ; THE '[' WORD ; ------------ ; ( -- ) ; Enters interpret mode. L13D1: DEFB '[' + $80 ; 'name field' DEFW L12CF ; 'link field' L13D4: DEFB $41 ; 'name length field' (immediate mode) L13D5: DEFW L13D7 ; 'code field' ; --- L13D7: RES 6,(IX+$3E) ; FLAGS JP (IY) ; to 'next'. ; ------------ ; THE ']' WORD ; ------------ ; ( -- ) ; Enters compile mode. L13DD: DEFB ']' + $80 ; 'name field' DEFW L1315 ; 'link field' L13E0: DEFB $01 ; 'name length field' L13E1: DEFW L13E3 ; 'code field' ; --- L13E3: SET 6,(IX+$3E) ; FLAGS JP (IY) ; to 'next'. ; --------------- ; THE 'EXIT' WORD ; --------------- ; ( -- ) ; Exits immediately from the word in whose definition it is contained. ; Cannot be used between DO and LOOP or +LOOP, nor between >R and R>. L13E9: DEFM "EXI" ; 'name field' DEFB 'T' + $80 DEFW L1387 ; 'link field' L13EF: DEFB $04 ; 'name length field' L13F0: DEFW L04B8 ; 'code field' ; ------------------- ; THE 'REDEFINE' WORD ; ------------------- ; REDEFINE name ; ( -- ) ; Takes word 'name' and replaces it with the most recent word in the ; dictionary. Updates entire dictionary to take changes into account. ; Most commonly used as ; EDIT name ; REDEFINE name L13F2: DEFM "REDEFIN" ; 'name field' DEFB 'E' + $80 DEFW L13EF ; 'link field' L13FC: DEFB $08 ; 'name length field' L13FD: DEFW L13FF ; 'code field' ; --- L13FF: CALL L0F2E ; blank stack LD HL,($3C31) ; CURRENT LD E,(HL) INC HL LD D,(HL) EX DE,HL ; transfer value to HL INC HL LD ($2705),HL ; store in pad PUSH HL ; (*) CALL L15C0 ; get 'name field' address LD ($270D),HL ; name field addr LD ($2707),BC ; parameter field addr LD ($270B),DE ; length field value LD HL,($3C37) ; STKBOT SBC HL,DE JP NZ,L14DA ; forward if not matched to Error 11. POP DE ; (*) RST 10H ; push word DE CALL L04B9 ; forth L1429: DEFW L1610 ; prvcur DEFW L063D ; find DEFW L1A0E ; end-forth. ; --- L1425: RST 18H ; pop word DE LD HL,$C3AF ADD HL,DE JP NC,L14CF ; EX DE,HL LD ($2703),HL CALL L15C0 ; get 'name field' address LD ($2701),HL L1441: PUSH HL LD ($2709),DE LD A,B OR C LD DE,($2707) JR Z,L1452 ; LD A,D OR E JR Z,L14CF ; L1452: POP HL LD BC,($270D) SBC HL,BC EX DE,HL ADD HL,DE LD ($2707),HL LD HL,($270B) ADD HL,DE LD BC,($2709) AND A SBC HL,BC LD ($270B),HL LD BC,$002E ; 46d ADD HL,BC BIT 7,H JR NZ,L147F ; LD BC,($3C3B) ; SPARE ADD HL,BC JR C,L14CF ; SBC HL,SP JR NC,L14CF ; L147F: LD HL,($2703) PUSH HL DEC HL DEC HL LD B,(HL) DEC HL LD C,(HL) LD HL,($2705) PUSH HL DEC HL DEC HL LD (HL),B DEC HL LD (HL),C POP HL ADD HL,DE POP BC AND A SBC HL,BC LD ($2705),HL LD DE,($2701) LD HL,($2709) AND A SBC HL,DE LD B,H LD C,L PUSH DE PUSH BC CALL L14DC ; RECLAIM LD HL,($270B) POP BC ADD HL,BC LD B,H LD C,L POP HL PUSH BC CALL L0F9E ; routine MAKE ROOM EX DE,HL ; LD HL,($270D) ; LD BC,($270B) ; ADD HL,BC ; POP BC ; PUSH BC ; PUSH HL ; LDIR ; POP DE POP BC CALL L14DC ; RECLAIM CALL L14F8 ; JP (IY) ; to 'next'. ; --- L14CF: LD HL,($3C31) ; CURRENT LD DE,($2705) DEC DE LD (HL),E INC HL LD (HL),D L14DA: RST 20H ; Error 11 DEFB $0B ; Error in REDEFINE or FORGET ; --------------------------- ; THE 'RECLAIMING' SUBROUTINE ; --------------------------- L14DC: LD HL,($3C37) ; fetch STKBOT AND A ; clear carry flag SBC HL,BC ; subtract number of bytes to reclaim. LD ($3C37),HL ; update STKBOT LD HL,($3C3B) ; fetch SPARE SBC HL,BC ; subtract number of bytes to reclaim. LD ($3C3B),HL ; update SPARE SBC HL,DE ; subtract RET Z ; return if same address. PUSH BC ; LD B,H ; LD C,L ; POP HL ; ADD HL,DE ; LDIR ; RET ; ; --- ; ; --- L14F8: LD BC,$3C31 ; CURRENT CALL L1557 ; CALL L1557 ; LD BC,$3C40 ; addr. of "FORTH" in RAM. L1504: LD HL,($3C37) ; STKBOT SCF ; SBC HL,BC ; RET C ; L150B: LD A,(BC) ; RLA ; INC BC ; JR NC,L150B ; INC BC ; INC BC ; CALL L1557 ; INC BC ; CALL L1557 ; L1519: CALL L15FB ; routine INDEXER ; ------------------------------------------------------- DEFW L0EC3 ; DE value L151E: DEFB $1C ; to L153A DEFW L1085 ; DE value L1521: DEFB $16 ; to L1537 DEFW L1108 ; DE value L1524: DEFB $13 ; to L1537 DEFW L11B5 ; DE value L1527: DEFB $18 ; to L153F DEFW $0000 ; zero end marker ; ------------------------------------------------------- L152A: LD HL,$FFF9 ADD HL,BC LD C,(HL) INC HL LD B,(HL) DEC HL ADD HL,BC LD B,H LD C,L JR L1504 ; ; ------------------------------------------------------- L1537: CALL L1557 ; ; -> L153A: CALL L1548 ; JR L1504 ; ; --- L153F: CALL L1557 ; INC BC ; CALL L1557 ; JR L1504 ; ; ------------------------------------------------------- ; XXX? L1548: CALL L1557 ; LD HL,L04B6 ; AND A ; SBC HL,DE ; RET Z ; CALL L159E ; JR L1548 ; ; --- ; often called twice ; --- L1557: LD A,(BC) ; lo byte LD E,A ; INC BC ; LD A,(BC) ; hi byte LD D,A ; DEC BC ; BC now unchanged, DE contents CALL L1568 ; routine below. header? EX DE,HL ; value to DE LD A,E ; LD (BC),A ; lo byte INC BC ; LD A,D ; LD (BC),A ; hi byte INC BC ; RET ; to next - BC+=2 ; --- L1568: LD HL,($2701) ; first bytes of pad. AND A ; SBC HL,DE ; subtract the DE value read from ; memory LD H,D ; LD L,E ; transfer that DE to HL as well RET NC ; return if HL was higher than DE LD HL,($2709) ; tape header SBC HL,DE JR NC,L1584 ; forward if higher to LD HL,($270D) SBC HL,DE JR C,L1592 ; forward if lower to LD HL,($270B) ; ADD HL,DE RET ; return ; --- L1584: LD HL,($2703) SBC HL,DE LD HL,($2707) RET C LD HL,($2705) ADD HL,DE RET ; --- L1592: LD HL,($2701) ADD HL,DE LD DE,($270D) AND A SBC HL,DE RET ; --- L159E: DEC DE LD A,(DE) RLA RET NC L15A2: DEC DE DEC DE LD A,(DE) LD L,A ; low byte LD H,$00 ; make high byte zero INC A ; test offset for $FF. JR NZ,L15B1 ; forward if not. LD A,(BC) LD L,A INC BC LD A,(BC) LD H,A INC BC L15B1: ADD HL,BC LD B,H LD C,L RET ; --- ; ; --- L15B5: DEFW L15B7 ; --- L15B7: RST 18H ; pop word DE EX DE,HL CALL L15E7 ; WORDSTART1 EX DE,HL RST 10H ; push word DE JP (IY) ; to 'next'. ; --- ; ; --- L15C0: PUSH HL LD E,(HL) INC HL LD D,(HL) L15C4: CALL L15FB ; routine INDEXER ; ------------------------------------------------------- DEFW L1108 L15C9: DEFB $0B ; to L15D4 - find parameter field DEFW L1085 L15CC: DEFB $08 ; to L15D4 - find parameter field DEFW $0000 ; zero end_marker. ; ------------------------------------------------------- L15CF: LD BC,$0000 ; zero indicates no parameter field. JR L15DB ; forward to consider total length. ; ------------------------------------------------------- L15D4: POP HL ; retrieve the code field address PUSH HL ; save it again INC HL ; step past the INC HL ; address word LD C,(HL) ; and get following address INC HL ; which if in RAM could be the LD B,(HL) ; parameter field to BC. ; -> L15DB: POP HL ; retrieve the code field address PUSH HL ; and save it again DEC HL ; the name length field DEC HL ; link field high order byte DEC HL ; link field low order byte DEC HL ; possible length field high LD D,(HL) ; save in D DEC HL ; possible length field low LD E,(HL) ; save in E ADD HL,DE ; add this length EX DE,HL ; and save result in DE. POP HL ; retrieve code field address ; -> ; indexes the header information of a FORTH word L15E7: DEC HL ; point to name length field ; => L15E8: LD A,H ; fetch high order byte of the ; header address. CP $3C ; compare to RAM location LD A,(HL) ; fetch length byte. RES 6,A ; reset the immediate mode bit JR C,L15F2 ; forward if definition is in ROM. ADD A,$02 ; else add extra for 'length field' L15F2: DEC HL ; step past the DEC HL ; link to previous word. L15F4: DEC HL ; now address last letter on name. DEC A ; decrement the length JR NZ,L15F4 ; loop back until at first letter HL. RET ; return. ; ------- ; INDEXER ; ------- ; indexerloop L15F9: INC HL ; step past the PUSH HL ; offset byte. ; -> Call Entry point L15FB: POP HL ; drop return address - points to byte ; after the call. LD A,(HL) ; read low-order byte INC HL ; increment address once PUSH HL ; push return address LD H,(HL) ; read high-order byte. LD L,A ; now HL holds the read word OR H ; test for two zeros. RET Z ; two zeros - return ; (ret addr is second NOP) SBC HL,DE ; compare to value passed in DE POP HL ; now increment the INC HL ; return address on machine stack. JR NZ,L15F9 ; loop back if read word is not ; equal to DE PUSH DE ; else preserve DE LD D,$00 ; a 1 byte relative jump. LD E,(HL) ; read one-byte offset. ADD HL,DE ; add to read address. POP DE ; restore DE JP (HL) ; >>> ; --- L1610: DEFW L0EC3 ; 'code field' - docolon DEFW L0E1F ; 1- DEFW L0E29 ; 2- DEFW L08B3 ; @ DEFW L0480 ; current DEFW L08B3 ; @ DEFW L08C1 ; ! DEFW L04B6 ; exit ; --------------------------------- ; THE 'FIND WORD IN RAM' SUBROUTINE ; --------------------------------- ; This subroutine is used by FORGET, EDIT and LIST. ; First use the standard FORTH word find to get address of word (in pad). ; If word does not exist then returned value will be zero. ; The lowest word in RAM is the FORTH word at L3C51 so a check is made ; against this address. L1620: CALL L04B9 ; forth DEFW L063D ; find L1625: DEFW L1A0E ; end-forth. RST 18H ; pop word DE LD HL,$C3AF ; i.e $0000 - $3C51 ADD HL,DE ; add to test value. RET C ; carry signals that word exists in RAM. ; return the address in DE. ; else generate an error code. RST 20H ; Error 13 DEFB $0D ; Error word not found or is in ROM. ; ----------------- ; THE 'FORGET' WORD ; ----------------- ; FORGET name. ; Erases the word 'name' and all subsequently defined names from the dictionary. L162F: DEFM "FORGE" ; 'name field' DEFB 'T' + $80 DEFW L13FC ; 'link field' L1637: DEFB $06 ; 'name length field' L1638: DEFW L163A ; 'code field' ; --- L163A: LD HL,($3C31) ; CURRENT LD DE,($3C33) ; CONTEXT AND A SBC HL,DE JP NZ,L14DA ; CALL L1620 ; findramword LD HL,$FFFB ADD HL,DE LD ($3C39),HL ; SPARE SET 2,(IX+$3E) ; FLAGS RST 20H ; Invoke error routine. DEFB $FF ; No error ; --------------- ; THE 'EDIT' WORD ; --------------- ; EDIT name ; Lists word 'name' at bottom of the screen to be edited. Lists 18 lines at ; a time, then waits for editing until ENTER is pressed. ; A new version of the word is entered at the end of the dictionary. ; While editing, cursor up and cursor down are needed to move the cursor ; from one line to another. DELETE LINE deletes one line. L1657: DEFM "EDI" ; 'name field' DEFB 'T' + $80 DEFW L1637 ; 'link field' L165D: DEFB $04 ; 'name length field' L165E: DEFW L1660 ; 'code field' ; --- L1660: CALL L1620 ; findramword SET 3,(IX+$3E) ; update FLAGS output -> input buffer JR L1675 ; forward to list routine the difference ; being that the listing will go to the ; lower screen. ; --------------- ; THE 'LIST' WORD ; --------------- ; LIST name ; ( -- ) ; Lists word 'name' on the screen. It must have been defined by :, DEFINER, ; or COMPILER. Lists about 18 lines at a time and waits for key depression ; (shifted space breaks). L1669: DEFM "LIS" ; 'name field' DEFB 'T' + $80 DEFW L165D ; 'link field' L166F: DEFB $04 ; 'name length field' L1670: DEFW L1672 ; 'code field' ; --- L1672: CALL L1620 ; findramword ; edit path joins here but carriage returns are printed as zeros. L1675: LD A,$0D ; prepare a carriage return. RST 08H ; print_ch BIT 3,(IX+$3E) ; test FLAGS output->input buffer? PUSH DE CALL NZ,L02D8 ; call if so to initialize buffer POP BC ; LD DE,(BC) LD A,(BC) LD E,A INC BC LD A,(BC) LD D,A DEC BC CALL L15FB ; routine INDEXER ; ------------------------------------------------------- L168A: DEFW L0EC3 ; DE value L168C: DEFB $0B ; offset to L1697 L168D: DEFW L1108 ; DE value L168F: DEFB $0D ; offset to L169C L1690: DEFW L1085 ; DE value L1692: DEFB $1F ; offset to L16B1 DEFW $0000 ; zero end-marker ; ------------------------------------------------------- L1695: RST 20H ; Error 14 DEFB $0E ; Word unlistable. ; Only words defined by ':', 'DEFINER' or 'COMPILER' are listable. ; ------------------------------------------------------- ; ':' L1697: LD HL,$0002 JR L16B4 ; ; --- L169C: PUSH DE LD HL,$0002 ADD HL,BC LD A,(HL) INC HL LD H,(HL) LD L,A DEC HL DEC HL DEC HL LD L,(HL) LD A,L RLCA SBC A,A LD H,A CALL L180E ; pr_int_hl? POP DE L16B1: LD HL,$0004 L16B4: ADD HL,BC PUSH HL PUSH BC CALL L17E4 ; POP DE POP BC CALL L17E4 ; LD (IX+$14),$01 ; LISTWSx L16C3: LD (IX+$16),$10 ; LISTWSx L16C7: CALL L1708 ; index_table JR C,L16D2 ; DEC (IX+$16) ; LISTWSx JP P,L16C7 ; L16D2: BIT 3,(IX+$3E) ; FLAGS JR NZ,L16E8 ; branch forward =-> JR C,L1702 ; LD HL,$3C26 ; KEYCOD LD (HL),$00 ; L16DF: LD A,(HL) ; AND A ; JR Z,L16DF ; loop back while zero CALL L04E4 ; check break JR L16C3 ; loop back ; =-> L16E8: PUSH AF RES 3,(IX+$3E) ; FLAGS PUSH BC CALL L04B9 ; forth DEFW L0578 ; retype - allow user to retype DEFW L0506 ; line - interpret buffer DEFW L1A0E ; end-forth. SET 3,(IX+$3E) ; FLAGS CALL L02D8 ; POP BC POP AF JR NC,L16C3 ; L1702: RES 3,(IX+$3E) ; FLAGS JP (IY) ; to 'next'. ; ------------------------------------------------------- ; called once L1708: LD A,($3C14) ; LISTWS2 LD ($3C15),A ; LISTWS3 LD (IX+$13),$05 ; LISTWS L1712: LD A,(BC) LD E,A INC BC LD A,(BC) LD D,A INC BC L1718: CALL L15FB ; routine INDEXER ; ------------------------------------------------------- L171B: DEFW L1283 ; L171D: DEFB $40 ; offset to L175D L171E: DEFW L1271 ; L1720: DEFB $44 ; offset to L1764 L1721: DEFW L12A4 ; L1723: DEFB $48 ; offset to L176B L1724: DEFW L129F ; L1726: DEFB $37 ; offset to L175D L1727: DEFW L128D ; L1729: DEFB $42 ; offset to L176B L172A: DEFW L1288 ; L172C: DEFB $38 ; offset to L1764 L172D: DEFW L1276 ; L172F: DEFB $3C ; offset to L176B L1730: DEFW L1323 ; L1732: DEFB $2B ; offset to L175D L1733: DEFW L1332 ; L1735: DEFB $36 ; offset to L176B L1736: DEFW L133C ; L1738: DEFB $33 ; offset to L176B L1739: DEFW L10E8 ; L173B: DEFB $29 ; offset to L1764 L173C: DEFW L1140 ; L173E: DEFB $26 ; offset to L1764 L173F: DEFW L1011 ; L1741: DEFB $3B ; offset to L177C L1742: DEFW L1064 ; L1744: DEFB $47 ; offset to L178B L1745: DEFW L104B ; L1747: DEFB $51 ; offset to L1798 L1748: DEFW L1379 ; L174A: DEFB $62 ; offset to L17AC L174B: DEFW L1396 ; L174D: DEFB $63 ; offset to L17B0 L174E: DEFW L04B6 ; L1750: DEFB $54 ; offset to L17A4 L1751: DEFW $0000 ; zero end-marker ; ------------------------------------------------------- ; default action L1753: CALL L17E1 ; L1756: DEC (IX+$13) ; LISTWS JR NZ,L1712 ; AND A RET ; --- L175D: LD HL,($3C14) ; LISTWS2 LD H,L INC L JR L1770 ; ; --- L1764: LD HL,($3C14) ; LISTWS2 LD H,L DEC H JR L1770 ; ; --- L176B: LD HL,($3C14) ; LISTWS2 DEC L LD H,L L1770: LD ($3C14),HL ; LISTWS2 LD (IX+$13),$01 ; LISTWS DEC (IX+$16) ; LISTWSx JR L1753 ; ; --- L177C: CALL L17DA ; RST 10H ; push word DE LD DE,$09B3 ; '.' addr L1783: CALL L17C1 ; routine INDENT CALL L1815 ; pr2 JR L1756 ; ; --- L178B: CALL L17DA ; RST 10H ; push word DE CALL L17DA ; RST 10H ; push word DE LD DE,$0AAF ; 'F.' addr JR L1783 ; ; --- L1798: LD A,(BC) PUSH AF CALL L17E1 ; POP AF RST 08H ; print_ch LD A,$20 ; a space character RST 08H ; print_ch JR L1756 ; ; --- L17A4: CALL L1808 ; pr_inline DEFB $0D ; newline DEFB ';' ; ; DEFB $8D ; inverted newline SCF ; RET ; ; --- L17AC: LD A,$29 ; character ')' - end of comment. JR L17B2 ; L17B0: LD A,$22 ; character '"' - quote L17B2: PUSH AF PUSH BC CALL L17E1 ; POP DE CALL L0979 ; pr_string1 LD B,D LD C,E POP AF RST 08H ; print_ch AND A RET ; ------------------------------------------------------- L17C1: LD A,($3C15) ; LISTWS3 AND A RET M PUSH BC ; preserve BC LD B,A ; transfer count to B LD A,$0D ; carriage return. RST 08H ; print_ch INC B ; test indentation. DEC B ; JR Z,L17D4 ; L17CF: LD A,$20 ; a space character RST 08H ; print_ch DJNZ L17CF ; L17D4: LD (IX+$15),$FF ; LISTWS3 POP BC ; restore BC RET ; return. ; --- L17DA: LD A,(BC) LD E,A INC BC LD A,(BC) LD D,A L17DF: INC BC RET ; --- L17E1: CALL L17C1 ; routine INDENT L17E4: EX DE,HL DEC HL LD A,(HL) BIT 7,A JR NZ,L17F0 ; CALL L15E8 ; routine WORDSTART JR L17FB ; ; --- L17F0: EX DE,HL CALL L15A2 ; INC DE LD A,(DE) LD L,A INC DE LD A,(DE) LD H,A ADD HL,DE ; pr_string_sp L17FB: LD A,(HL) AND $7F RST 08H ; print_ch BIT 7,(HL) INC HL JR Z,L17FB ; LD A,$20 RST 08H ; print_ch RET ; --------------------------------------- ; THE 'INLINE PRINT STRING SPACE' ROUTINE ; --------------------------------------- ; L1808: EX (SP),HL CALL L17FB ; pr_string_sp EX (SP),HL RET ; --------------------------- ; THE 'PRINT INTEGER' ROUTINE ; --------------------------- ; in HL ; -> called twice L180E: LD DE,$09B3 ; '.' addr PUSH DE ; but save it as we need DE? EX DE,HL ; transfer HL to DE. RST 10H ; push word DE, was HL, on Data Stack. POP DE ; restore L09B3 again ; -> called twice. L1815: PUSH BC ; preserve BC. CALL L04BF ; executes '.' word ; the '.' exits so expects another word here L1819: DEFW L181B L181B: DEFW L181D L181D POP BC ; POP BC ; restore BC. RET ; return. ; --------------------------------- ; THE 'CASSETTE INTERFACE' ROUTINES ; --------------------------------- ; --- ; tape??? ; --- L1820: PUSH IY PUSH HL POP IY LD HL,L1892 PUSH HL LD HL,$E000 BIT 7,C JR Z,L1832 ; LD H,$FC L1832: INC DE DEC IY DI XOR A L1837: LD B,$97 L1839: DJNZ L1839 ; OUT ($FE),A XOR $08 INC L JR NZ,L1843 ; INC H L1843: JR NZ,L1837 ; LD B,$2B L1847: DJNZ L1847 ; OUT ($FE),A LD L,C LD BC,$3B08 L184F: DJNZ L184F ; LD A,C OUT ($FE),A LD B,$38 JP L188A ; L1859: LD A,C BIT 7,B L185C: DJNZ L185C ; JR NC,L1864 ; LD B,$3D L1862: DJNZ L1862 ; L1864: OUT ($FE),A LD B,$3A JP NZ,L1859 ; DEC B XOR A L186D: RL L JP NZ,L185C ; DEC DE INC IY LD B,$2E LD A,$7F IN A,($FE) RRA RET NC LD A,D CP $FF RET NC OR E JR Z,L188F ; LD L,(IY+$00) L1887: LD A,H XOR L LD H,A L188A: XOR A SCF JP L186D ; JUMP back ; --- L188F: LD L,H JR L1887 ; L1892: POP IY ; restore the original IY value so that ; words can be used gain. EX AF,AF' ;; LD B,$3B ; L1897: DJNZ L1897 ; self-loop for delay. XOR A OUT ($FE),A LD A,$7F ; read the port $7FFE IN A,($FE) ; keyrows SPACE to V. RRA EI ; Enable Interrupts. JP NC,L04F0 ; jump if SPACE pressed to Error 3 ; 'BREAK pressed'. EX AF,AF' ;; RET ; return. ; --- ; READ BYTES FROM TAPE ; --- L18A7: DI PUSH IY PUSH HL POP IY LD HL,L1892 PUSH HL LD H,C EX AF,AF' ; save carry XOR A LD C,A L18B5: RET NZ L18B6: LD L,$00 L18B8: LD B,$B8 CALL L1911 ; JR NC,L18B5 ; LD A,$DF CP B JR NC,L18B6 ; INC L JR NZ,L18B8 ; L18C7: LD B,$CF CALL L1915 ; JR NC,L18B5 ; LD A,B CP $D8 JR NC,L18C7 ; CALL L1915 ; RET NC CALL L18FC ; RET NC CCF RET NZ JR L18F0 ; ; --- L18DF: EX AF,AF' JR NC,L18E7 ; LD (IY+$00),L JR L18EC ; ; --- L18E7: LD A,(IY+$00) XOR L RET NZ L18EC: INC IY DEC DE EX AF,AF' L18F0: CALL L18FC ; RET NC LD A,D OR E JR NZ,L18DF ; LD A,H CP $01 L18FB: RET ; --- L18FC: LD L,$01 L18FE: LD B,$C7 CALL L1911 ; RET NC LD A,$E2 CP B RL L JP NC,L18FE ; LD A,H XOR L LD H,A SCF RET ; --- L1911: CALL L1915 ; RET NC L1915: LD A,$14 L1917: DEC A JR NZ,L1917 ; AND A L191B: INC B RET Z LD A,$7F IN A,($FE) RRA RET NC XOR C AND $10 JR Z,L191B ; LD A,C CPL LD C,A SCF RET ; --------------- ; THE 'SAVE' WORD ; --------------- ; SAVE name. ; Saves entire dictionary in RAM on a dictionary type cassette file with the ; given name. Makes a noise on the internal loudspeaker. L192D: DEFM "SAV" ; 'name field' DEFB 'E' + $80 DEFW L166F ; 'link field' L1933: DEFB $04 ; 'name length field' L1934: DEFW L0EC3 ; 'code field' - docolon ; --- DEFW L1A10 ; word to pad DEFW L1A4F ; prep some sort of header? DEFW L04B6 ; exit ; ---------------- ; THE 'BSAVE' WORD ; ---------------- ; BSAVE name ; (m, n -- ) ; Save n bytes to bytes type cassette file 'name' starting at ; address m. ; L193C: DEFM "BSAV" ; 'name field' DEFB 'E' + $80 DEFW L1933 ; 'link field' L1943: DEFB $05 ; 'name length field' L1944: DEFW L0EC3 ; 'code field' - docolon ; --- L1946: DEFW L1A3D ; prep_header DEFW L1A4F ; prep some sort of header? DEFW L04B6 ; exit ; ---------------- ; THE 'BLOAD' WORD ; ---------------- ; BLOAD name ; (m, n -- ) ; Load at most n bytes of bytes type cassette file 'name' starting at ; address m. ERROR 10 if the file has more than m bytes. ; L194C: DEFM "BLOA" ; 'name field' DEFB 'D' + $80 DEFW L1943 ; 'link field' L1953: DEFB $05 ; 'name length field' L1954: DEFW L0EC3 ; 'code field' - docolon ; --- DEFW L1A3D ; prep_header DEFW L1A74 ; ld-bytes?? DEFW L1AB8 ; tapeFF DEFW L04B6 ; exit ; ----------------- ; THE 'VERIFY' WORD ; ----------------- ; VERIFY name ; ( -- ) ; Verifies dictionary on tape against dictionary in RAM. L195E: DEFM "VERIF" ; 'name field' DEFB 'Y' + $80 DEFW L1953 ; 'link field' L1966: DEFB $06 ; 'name length field' L1967: DEFW L0EC3 ; 'code field' - docolon ; --- L1969: DEFW L1A10 ; word to pad DEFW L1271 ; branch L196D: DEFW $000F ; 15 bytes forward to L197D ; ------------------ ; THE 'BVERIFY' WORD ; ------------------ ; BVERIFY name ; (m, n -- ) ; Verify at most n bytes of bytes type cassette file 'name' against ; RAM starting at address m. ERROR 10 if the file has more than m bytes. ; For BLOAD and BVERIFY, if m = 0, then starts at the address the bytes ; were saved from. If n = 0, then doesn't care about the length. ; L196F: DEFM "BVERIF" ; 'name field' DEFB 'Y' + $80 DEFW L1966 ; 'link field' L1978: DEFB $07 ; 'name length field' L1979: DEFW L0EC3 ; 'code field' - docolon ; --- L197B: DEFW L1A3D ; prep_header ; -> L197D: DEFW L1A74 ; ld_bytes DEFW L1ABE ; tape00 DEFW L04B6 ; exit ; --------------- ; THE 'LOAD' WORD ; --------------- ; LOAD name ; ( -- ) ; Searches for a dictionary cassette file 'name' and loads it in, adding it ; to end of old dictionary. Writes to the screen all files found on tape. ; For best results turn the tone control on the tape recorder right down ; (as bass as possible) and the volume control to about three-quarters ; maximum. L1983: DEFM "LOA" ; 'name field' DEFB 'D' + $80 DEFW L1978 ; 'link field' L1989: DEFB $04 ; 'name length field' L198A: DEFW L0EC3 ; 'code field' - docolon ; --- L198C: DEFW L1A10 ; word to pad DEFW L1A0E ; end-forth. LD HL,($3C37) ; STKBOT LD ($230E),HL EX DE,HL LD HL,$FFCC ADD HL,SP AND A SBC HL,DE LD ($230C),HL CALL L04B9 ; forth L19A4: DEFW L1A74 ; ld_bytes DEFW L1AB8 ; tapeFF DEFW L1A0E ; end-forth. LD BC,($3C37) ; STKBOT LD HL,$3C50 LD ($2701),HL INC HL LD ($2709),HL LD HL,($2325) ADD HL,BC LD ($3C37),HL ; STKBOT LD HL,$C3AF ADD HL,BC LD ($270B),HL LD DE,($2329) ADD HL,DE LD DE,($3C4C) LD ($3C4C),HL PUSH BC PUSH DE L19D4: LD ($270D),SP CALL L1504 ; POP BC POP HL L19DD: BIT 7,(HL) INC HL JR Z,L19DD ; INC HL INC HL LD (HL),C INC HL LD (HL),B LD HL,($3C37) ; STKBOT LD BC,$000C ; allow twelve bytes for underflow. ADD HL,BC LD ($3C3B),HL ; SPARE JP (IY) ; to 'next'. ; --- L19F3: DEFW L0EC3 ; 'code field' - docolon DEFW L104B ; stk_data DEFB $20 ; a space delimiter DEFW L05AB ; word (to pad) DEFW L1A0E ; end-forth. ; --- L19FC: CALL L0F2E ; blank stack L19FF: RST 18H ; pop word DE LD A,$20 ; LD (DE),A ; LD DE,$270C ; LD HL,$27FF ; CALL L07FA ; routine SPACE_FILL JP (IY) ; to 'next'. ; --- L1A0E: DEFW L18FB ; location of RET instruction. ; --- L1A10: DEFW L0EC3 ; 'code field' - docolon DEFW L19F3 ; word to pad DEFW L1A0E ; end-forth. XOR A ; LD ($2301),A ; LD HL,$3C51 ; LD ($230E),HL ; EX DE,HL ; LD HL,($3C37) ; STKBOT AND A ; SBC HL,DE LD ($230C),HL LD HL,($3C4C) LD ($2310),HL LD HL,$3C31 ; CURRENT LD DE,$2312 LD BC,$0008 ; LDIR ; JP (IY) ; to 'next'. ; --- L1A3D: DEFW L0EC3 ; 'code field' - docolon DEFW L19F3 ; word to pad DEFW L1011 ; stack next word DEFW $230C ; header location DEFW L08C1 ; ! store int at address DEFW L1011 ; stack next word DEFW $230E ; header location DEFW L08C1 ; ! store int at address DEFW L04B6 ; exit ; --- L1A4F: DEFW L1A51 L1A51: LD A,($2302) ; length of word in pad AND A JR Z,L1AB6 ; forward if null. LD HL,($230C) LD A,H OR L JR Z,L1AB6 ; PUSH HL LD DE,$0019 ; LD HL,$2301 ; pad using ROM priority LD C,D ; CALL L1820 ; POP DE LD HL,($230E) ; LD C,$FF CALL L1820 ; JP (IY) ; to 'next'. ; --- ; ld_bytes ; --- L1A74: DEFW L1A76 L1A76: LD DE,$0019 LD HL,$231A LD C,D SCF CALL L18A7 ; JR NC,L1A76 ; loop back until read LD DE,$231A LD A,(DE) AND A JR NZ,L1A95 ; CALL L1808 ; pr_inline ; --- L1A8D: DEFB $0D ; newline DEFM "Dict" DEFB ':' + $80 ; L1A93: JR L1A9F ; ; --- L1A95: CALL L1808 ; pr_inline L1A98: DEFB $0D ; newline DEFM "Bytes" DEFB ':' + $80 ; ; --- L1A9F: LD HL,$2301 LD BC,$0B0B JR L1AA9 ; ; --- L1AA7: LD A,(DE) RST 08H ; print_ch L1AA9: LD A,(DE) CP (HL) JR NZ,L1AAE ; DEC C L1AAE: INC HL INC DE DJNZ L1AA7 ; JR NZ,L1A76 ; JP (IY) ; to 'next'. ; --- L1AB6: RST 20H ; Error 10 DEFB $0A ; Tape error ; --- ; ; --- L1AB8: DEFW L1ABA ; headerless 'code field' L1ABA: LD B,$FF JR L1AD0 ; forward to +-> ; --- ; ; --- L1ABE: DEFW L1AC0 ; headerless 'code field' L1AC0: LD HL,$2312 LD DE,$232B LD B,$08 L1AC8: LD A,(DE) INC DE CP (HL) INC HL JR NZ,L1AB6 ; back to tape error DJNZ L1AC8 ; back for all 8 ; common code - B is $00 from above or $FF from previous. L1AD0: LD HL,($230C) LD DE,($2325) LD A,H OR L JR Z,L1ADF ; skip if zero SBC HL,DE JR C,L1AB6 ; back to tape error L1ADF: LD HL,($230E) LD A,H OR L JR NZ,L1AE9 ; skip if zero LD HL,($2327) L1AE9: LD C,$FF RR B CALL L18A7 ; JR NC,L1AB6 ; back to report tape error JP (IY) ; to 'next'. ; ========================================================== ; THE 'FLOATING POINT ARITHMETIC' ROUTINES ; ========================================================== ; --------------------- ; THE 'PREP_FP' ROUTINE ; --------------------- ; ( f1, f2 -- m1, m2 ) ; -> from add/mult/div ; Entered with two floating point numbers on the stack. ; The exponents are stored in the first two bytes of FP_WS and the third byte ; is loaded with the manipulated result sign. ; the two exponent locations on the Data Stack are blanked leaving just the ; binary coded mantissas. ; Begin by clearing the first part of the workspace. L1AF4: LD BC,$3C0F ; byte 15 of the 19 bytes at FP_WS XOR A ; clear accumulator. L1AF8: LD (BC),A ; clear the workspace. DEC C ; decrement low byte of address. JR NZ,L1AF8 ; and back until at $3C00 ; LD HL,($3C3B) ; fetch end of data stack+1 from SPARE. LD DE,$FFFC ; prepare -4 DEC HL ; point to last byte of stack. LD C,(HL) ; sign/exponent of (f2) to C. LD (HL),A ; replace with zero to take overflow. ADD HL,DE ; subtract four from address ; update system variable SPARE - this could be deferred. INC HL ; point to location after (f1). LD ($3C3B),HL ; update system variable SPARE DEC HL ; point to exponent of (f1) LD B,(HL) ; sign/exponent of (f1) to B. LD (HL),A ; replace with zero. ; At this stage we have the sign/exponent of (f1) in B and the sign/exponent ; of (f2) in C. The next section places the sign bit of (f1) in but 7 of A ; and the sign bit of (f2) in bit 6 of A. The other bits are of no importance. LD A,C ; transfer C to A. RRCA ; rotate sign bit to bit 6. XOR B ; XOR B AND $7F ; mask off bits to restore XOR B ; bit 6 as it was, bit 7 of B to A. L1B13 LD ($3C02),A ; FP_WS_02 see L1C2F RES 7,B ; make both numbers RES 7,C ; positive LD ($3C00),BC ; store the exponents at start of FP_WS INC HL ; point to (f2) again. EX DE,HL ; transfer f2 pointer to DE, HL now -4 ADD HL,DE ; subtract four to point HL at (f1) RET ; return. ; On exit, HL -> (f1), DE -> (f2), B = exponent of (f1), C = exponent of (f2). ; ----------------------------- ; THE 'SHIFT_ADDEND' SUBROUTINE ; ----------------------------- L1B22: LD A,$09 CP B JR NC,L1B28 ; LD B,A ; set shift counter to nine. i.e clear. L1B28: LD C,$04 ; four bytes INC HL INC HL INC HL ; point to highest byte XOR A ; prepare to start with a blank nibble. L1B2E: RRD ; A=0000 XXXX --> 7654->3210 =(HL) ; \_____<-______/ DEC HL ; point to next lower byte on Data Stack DEC C ; decrement the byte counter. JR NZ,L1B2E ; loop for all 4 bytes = 1 nibble shift INC HL ; set pointer to start of number again DJNZ L1B28 ; decrement the shift counter and loop. ADD A,$FB ; add minus five to last nibble lost ; will set the carry flag if 5 or more. PUSH HL ;; preserve pointer to start of addend. L1B3A: LD A,(HL) ; fetch the pair of BCD nibbles. ADC A,B ; increment if carry set (B = 0) DAA ; Decimal Adjust Accumulator ; ($99 becomes $00 with carry set). LD (HL),A ; put nibbles back. INC HL ; point to next significant pair of ; binary coded decimal digits. JR C,L1B3A ; and ripple any rounding through. POP HL ;; retrieve the pointer to start. RET ; return. ; --------------------------- ; THE 'BCD NEGATE' SUBROUTINE ; --------------------------- ; Negates the four byte, 8 nibble, binary coded decimal on the Data Stack. ; For example -123.456 ; is prepared as $00 $12 $34 $56 ; and negated as $99 $87 $65 $34 L1B43: PUSH BC ; preserve the two PUSH HL ; main registers used. LD B,$04 ; set byte counter to four. AND A ; clear carry. L1B48: LD A,$00 ; set to zero without disturbing carry. SBC A,(HL) ; subtract pair of digits DAA ; Decimal Adjust Accumulator ; adjusts as if from 100 setting carry LD (HL),A ; place adjusted decimals back. INC HL ; next location on Data Stack. DJNZ L1B48 ; loop for all 4 bytes. POP HL ; restore the POP BC ; saved registers. RET ; return. ; ------------------------------ ; THE 'BCD OPERATION' SUBROUTINE ; ------------------------------ ; This versatile routine performs the binary coded decimal addition of ; two floating point values with C = 1. ; The second entry point is used in multiplication. ; -> L1B53: LD C,$01 ; signal the operation is addition. ; -> (with c!=0) L1B55: PUSH HL ; preserve the PUSH DE ; three main PUSH BC ; registers. LD A,C ; treat C as a binary coded decimal. AND $0F ; isolate the right-hand nibble. LD B,A ; transfer R.H. nibble to B XOR C ; A now has L.H. nibble. LD C,A ; place in C. ; this next magical routine converts the two BCD digits to binary. ; imagine we started with ninety-nine so C = 1001 0000 and B = 0000 1001 RRCA ; 0100 1000 RRCA ; 0010 0100 ADD A,C ; 1011 0100 RRCA ; 0101 1010 ADD A,B ; 0110 0011 = 99 binary LD C,A ; binary multiplier in C ; note that for simple addition C is unchanged and still contains 1. LD B,$04 ; four bytes to consider XOR A ; clear accumulator ensuring no initial ; carry is fed into the loop. ; loop L1B67: PUSH BC ; push the counters. PUSH DE ; push the (f2) pointer PUSH HL ; push the (f1) pointer. ADD A,(HL) ; add any running carry to (f1) cell. DAA ; Decimal Adjust Accumulator ; possibly setting carry. LD L,A ; result to L LD A,(DE) ; fetch (f2) cell value. LD H,$00 ; set high bytes H and D to LD D,H ; zero without disturbing carry RL H ; now pick up any carry in H. AND A ; test (f2) cell value. JR Z,L1B91 ; skip forward to just store the carry ; result if the addend value is zero. LD E,A ; else DE now holds cell value. L1B77: SRL C ; shift counter C 0->76543210->C JR NC,L1B83 ; skip addition if no carry. ; else perform HL=HL+DE in BCD. LD A,L ; fetch low byte of (f1) cell. ADD A,E ; add to low byte of (f2) cell. DAA ; DAA. LD L,A ; result in L and carry. LD A,H ; fetch high byte possibly 1 from carry ADC A,D ; add in any carry from above (D=0) DAA ; comes into play with multiplication. LD H,A ; result to H. L1B83: INC C ; test the counter for zero. DEC C ; (will be if addition) JR Z,L1B91 ; forward when zero -> ; else is BCD multiplication - double the DE value. LD A,E ; ADD A,A ; DAA ; LD E,A ; LD A,D ; ADC A,A ; DAA ; LD D,A ; JR L1B77 ; back to continue multiplying by C. ; --- ; -> L1B91: EX DE,HL ; transfer result to DE. POP HL ; pop (f1) cell pointer LD (HL),E ; insert result. LD A,D ; transfer any carry to A POP DE ; pop the (f2) pointer POP BC ; pop the counter, and initial C value. INC DE ; increment (f2) cell pointer. INC HL ; increment (f1) cell pointer. DJNZ L1B67 ; loop back for all 4 bytes. POP BC ; restore the POP DE ; three main POP HL ; registers. RET ; return. ; ------------- ; THE 'F-' WORD ; ------------- ; ( f1, f2 -- f1-f2 ) ; Subtracts top two floating point numbers. ; ; just flip the sign and then do floating point addition. L1B9F: DEFB 'F' ; 'name field' DEFB '-' + $80 DEFW L1989 ; 'link field' L1BA3: DEFB $02 ; 'name length field' L1BA4: DEFW L0EC3 ; 'code field' - docolon ; --- L1BA6: DEFW L1D0F ; fnegate DEFW L1A0E ; end-forth. JR L1BB3 ; forward to floating point addition. ; ------------- ; THE 'F+' WORD ; ------------- ; ( f1, f2 -- f1+f2 ) ; Adds top two floating point numbers. L1BAC: DEFB 'F' ; 'name field' DEFB '+' + $80 DEFW L1BA3 ; 'link field' L1BB0: DEFB $02 ; 'name length field' L1BB1: DEFW L1BB3 ; 'code field' ; --- L1BB3: CALL L1AF4 ; PREP_FP LD A,C ; take exponent of second number (f2). SUB B ; subtract exponent of first (f1). PUSH AF ; save result flags. JR NC,L1BC1 ; forward if second number >= first. EX DE,HL ; else swap the pointers. NEG ; negate negative result. LD (IX+$00),B ; place B in FP_WS_0 (was C). L1BC1: LD B,A ; put positive subtraction result in B. CALL NZ,L1B22 ; routine SHIFT_ADDEND aligns digits if ; exponents are not equal. POP AF ; retrieve subtraction result flags. JR NC,L1BC9 ; forward is second number was >= first. EX DE,HL ; else switch the pointers back. L1BC9: LD B,$02 ; two floating point numbers to consider LD C,(IX+$02) ; FP_WS_02 L1BCE: RL C ; test sign bit first bit 7 then bit 6. CALL C,L1B43 ; routine BCD neg if carry EX DE,HL ; switch number pointers. DJNZ L1BCE ; decrement counter and loop if second ; number still to do. CALL L1B53 ; the BCD ADDITION routine. ; The routine preserves main registers so HL->(f1), DE->(f2) and B is zero. DEC DE ; point to highest byte of result which ; could be $99 if one negative number ; involved or $98 if two negatives. LD A,(DE) ; fetch the result sign byte. ADD A,$68 ; add $68 causing carry if negative. RR B ; pick up carry in bit 7 of B, which ; was zero so zero flag now set if none. LD (IX+$02),B ; place result sign in FP_WS_02 CALL NZ,L1B43 ; routine BCD_NEGATE if negative result. ; if the L1BE5: LD A,(DE) ; AND A ; JR NZ,L1C02 ; ; else A is zero. DEC (IX+$00) ; decrement the result exponent FP_WS_00 DEC (IX+$00) ; as two nibbles will be moved at a time PUSH DE ; save pointer to 4th byte LD H,D ; make HL LD L,E ; equal to DE DEC HL ; minus one. LD BC,$03FF ; counter for three bytes. The $FF ; value ensures B is not affected by ; the LDD instruction. Also A is 0. L1BF6: OR (HL) ; (detects if the three bytes are zero) LDD ; copy HL contents one location higher ; to that addressed by DE. Also dec bc. DJNZ L1BF6 ; repeat for all 3 bytes EX DE,HL ; make HL address lowest location LD (HL),B ; and insert a zero into vacated byte. POP DE ; restore the pointer to the 4th byte. JR NZ,L1BE5 ; jump back to the end test if something ; was being shifted through. ; else all four bytes are zero - i.e. the result of the addition is zero. JP (IY) ; to 'next'. ; --- ; The branch was to here, from the end test above, when the 4th byte had been ; filled. ; Before joining common code, ensure that the initial block move will be ; ineffective. L1C02: LD D,H ; make DE the same as HL - the source LD E,L ; and the destination are the same. ; -> common code from mult and above. L1C04: PUSH DE ; save start location. LD BC,$0004 ; 4 bytes to consider. LDIR ; block move sets DE to one past dest. POP HL ; restore start of source. DEC DE ; DE now addresses 4th byte. L1C0C: LD A,(DE) ; load the 4th byte to accumulator. AND A ; test for zero. JR Z,L1C21 ; skip forward if so. CP $10 ; test if one or two nibbles populated ; setting carry for a single nibble. SBC A,A ; $00 for two nibbles, $FF for one. INC A ; $01 $00 INC A ; $02 for two nibbles, $01 for one :-) LD B,A ; nibble count to B. ADD A,(IX+$00) ; add count to FP_WS_00 the result LD ($3C00),A ; exponent and place back in FP_WS_00. CALL L1B22 ; routine 'shift_addend' moves all the ; nibbles to the right. JR L1C0C ; back to pick up byte and then to ; next routine. ; --- ; now test for a result that is too large or too small. ; Note. these results may have arisen from multiplication or addition. L1C21: LD A,($3C00) ; fetch result exponent from FP_WS_00 DEC A ; decrement? CP $BF ; compare lower limit INC A ; increment? JR NC,L1C3D ; forward if less to ZERO_RSLT CP $80 ; compare upper limit JR NC,L1C3B ; forward to Error 8 - Overflow LD B,A ; save unsigned exponent in B. ; now combine result sign and the exponent. ; for addition then FP_WS_02 contains either $80 or $00 and most of what ; follows does not apply. ; for multiplication then bit 7 is sign of (f1) bit 6 is sign of (f2). L1C2F LD A,($3C02) ; FP_WS_02 see L1B13 LD C,A ; save a copy in C RLA ; rotate bit 6 to 7 XOR C ; XOR bit 7 - minus * minus = a plus. AND $80 ; only interested in bit 7. XOR B ; combine with exponent. LD (DE),A ; and place in sign/exp on Data Stack. JP (IY) ; to 'next'. ; --- L1C3B: RST 20H ; Error 8. DEFB $08 ; Overflow in floating-point arithmetic. ; ------------------------------------ ; THE 'ZERO RESULT' TERMINATING BRANCH ; ------------------------------------ L1C3D: LD BC,$0400 ; count 4 bytes, fill byte is zero. L1C40: LD (HL),C ; insert a zero. INC HL ; next location. DJNZ L1C40 ; repeat for all 4 bytes. JP (IY) ; to 'next'. ; ------------- ; THE 'F*' WORD ; ------------- ; (f1, f2 -- f1*f2) ; Multiplies top two floating point numbers and leaves result on the stack. L1C46: DEFB 'F' ; 'name field' DEFB '*' + $80 DEFW L1BB0 ; 'link field' L1C4A: DEFB $02 ; 'name length field' L1C4B: DEFW L1C4D ; 'code field' ; --- L1C4D: CALL L1AF4 ; routine PREP_FP prepares the two ; numbers on the Data Stack placing the ; exponents and signs in FP_WS. XOR A ; set accumulator to zero. CP B ; compare to exponent of (f1). SBC A,A ; $00 if zero or $FF AND C ; combine with exponent of (f2). JR Z,L1C3D ; back if zero to exit via ZERO_RSLT. PUSH HL ; save pointer to first number - result. LD BC,$3C02 ; set BC to location before free ; workspace set to zero by PREP_FP. PUSH BC ; push onto machine stack. LD B,$03 ; count three bytes - six nibbles. L1C5D: LD C,(HL) ; fetch BCD pair to C INC HL ; address more significant pair. EX (SP),HL ; Data Stack pointer to machine stack, ; workspace pointer to HL. INC HL ; increment workspace pointer. CALL L1B55 ; routine BCD_OP multiplies C by each ; of the 4 bytes of (f2) laying the ; result down in workspace at HL EX (SP),HL ; swap in multiplier pointer to HL, ; workspace pointer to machine stack. DJNZ L1C5D ; repeat for all three bytes. LD BC,($3C00) ; fetch raw exponents from FP_WS_00/01 LD A,B ; add the exponents ADD A,C ; together. SUB $42 ; adjust for sign LD ($3C00),A ; put the result back in FP_WS_00. POP HL ; pop workspace pointer to HL. POP DE ; pop result pointer to DE. JR L1C04 ; back to common code to copy the 4 ; bytes from the workspace to the ; Data Stack and then set exponent ; and sign. ; ------------- ; THE 'F/' WORD ; ------------- ; ( f1, f2 -- f1/f2 ) ; Divides two floating point numbers. L1C76: DEFB 'F' ; 'name field' DEFB '/' + $80 DEFW L1C4A ; 'link field' L1C7A: DEFB $02 ; 'name length field' L1C7B: DEFW L1C7D ; 'code field' ;--- L1C7D: CALL L1AF4 ; routine PREP_FP prepares the two ; numbers (f1) and (f2) placing the ; raw exponents in the first two ; locations of workspace, the signs in ; the next location and clearing the ; sixteen remaining locations. ; This must be the one that uses them ; all. XOR A ; set accumulator to zero. CP B ; compare to exponent of dividend (f1). JR Z,L1C3D ; forward if zero to ZERO_RSLT. CP C ; compare to exponent of divisor (f2). JR Z,L1C3B ; back if zero to Error 8 - Overflow. ; division by zero. ; HL points to first number on stack, DE to second. INC DE ; INC DE ; LD A,(DE) ; get first two digits to A DEC DE ; DEC DE ; back to first ADD A,$01 ; add one (e.g. 99 would give 9A) DAA ; adjust (e.g. $9A would be $00 carry) EX AF,AF' ; save the flags EX DE,HL ; HL now points to divisor CALL L1B43 ; routine BCD negate the divisor EX DE,HL ; point back again. PUSH HL ; save pointer to first - the result. LD DE,$3C10 ; destination FP_WS_10 LD BC,$0004 ; four bytes LDIR ; copy to end of FP_WS ; (+ one byte of list_ws) EX DE,HL ; HL points to last cell plus one. DEC HL ; Now points to last byte copied. LD B,$05 ; count 5. ; loop L1CA2: PUSH DE ; LD A,(HL) ; DEC HL ; LD E,(HL) ; EX AF,AF' ; LD C,A ; EX AF,AF' ; INC C ; DEC C ; JR NZ,L1CB0 ; LD E,A ; JR L1CCB ; ; --- L1CB0: PUSH BC ; LD B,$02 ; L1CB3: LD D,$10 ; L1CB5: SLA E ; RLA ; RL D ; JR NC,L1CB5 ; INC D ; L1CBD: SUB C ; DAA ; INC E ; JR NC,L1CBD ; DEC D ; JR NZ,L1CBD ; ADD A,C ; DAA ; DEC E ; DJNZ L1CB3 ; POP BC ; L1CCB: LD C,E ; POP DE ; INC C ; DEC C ; JR Z,L1CE8 ; PUSH HL ; DEC HL ; DEC HL ; CALL L1B55 ; bcd_op mult PUSH DE ; LD DE,$FFFB ; -4 ADD HL,DE ; LD DE,$3C03 ; FP_WS_03 LD A,C ; LD (DE),A ; CALL L1B53 ; bcd_op add POP DE ; POP HL ; INC HL ; INC B ; L1CE8: DJNZ L1CA2 ; LD HL,($3C00) ; FP_WS LD A,H ; SUB L ; ADD A,$40 ; LD HL,$3C08 ; FP_WS LD B,A ; LD A,($3C0B) ; AND A ; JR NZ,L1CFE ; DEC B ; DEC B ; DEC HL ; L1CFE: LD (IX+$00),B ; POP DE ; JP L1C04 ; back to common code to copy the 4 ; bytes from the workspace to the ; Data Stack and then set exponent ; and sign. ; ------------------ ; THE 'FNEGATE' WORD ; ------------------ ; ( f -- -f ) ; Floating point negation. ; Toggle the sign bit unless the number is zero (four zero bytes). L1D05: DEFM "FNEGAT" ; 'name field' DEFB 'E' + $80 DEFW L1C7A ; 'link field' L1D0E: DEFB $07 ; 'name length field' L1D0F: DEFW L1D11 ; 'code field' ; --- L1D11: RST 18H ; pop word from data stack to DE. LD A,D ; exponent byte to A. AND A ; test for zero. JR Z,L1D18 ; forward if so to leave undisturbed. XOR $80 ; else toggle the sign bit L1D18: LD D,A ; exponent byte to D. RST 10H ; push word DE on data stack. JP (IY) ; to 'next'. ; -------------- ; THE 'INT' WORD ; -------------- ; (f -- n) ; Converts signed floating point number to signed single length integer. ; Truncates towards zero. ; Result in range -32768 to 32767 L1D1C: DEFM "IN" ; 'name field' DEFB 'T' + $80 DEFW L1D0E ; 'link field' L1D21: DEFB $03 ; 'name length field' L1D22: DEFW L1D24 ; 'code field' ; --- L1D24: LD HL,($3C3B) ; fetch value from SPARE. DEC HL ; now points to end of data stack. LD DE,$0000 ; initialize 16-bit result. L1D2B: LD A,(HL) ; fetch the exponent byte. RLCA ; double exponent moving sign bit to 0. CP $82 ; compare exponent to plus 1. JR C,L1D45 ; forward if number is smaller than 1 ; to return the result DE. ; else the number is >= 1.0 XOR A ; clear accumulator. DEC HL ; point to the first pair of BCD digits. CALL L0732 ; call shift_fp INC HL ; point to exponent. EX DE,HL ; pointer to DE, integer to HL. ; before adding in the nibble from the mantissa, multiply any previous result ; by ten. LD B,H ; make a copy of HL in BC. LD C,L ; ADD HL,HL ; * 2 ADD HL,HL ; * 4 ADD HL,BC ; * 5 ADD HL,HL ; * 10 LD C,A ; leftmost nibble from mantissa to C. LD B,$00 ; prepare to add just the nibble. ADD HL,BC ; add into the result. EX DE,HL ; switch back to DE JR L1D2B ; back to loop. ; --- L1D45: DEC HL ; skip redundant components of Floating DEC HL ; Point number addressing the ; lower two bytes on the data stack. LD (HL),D ; insert high-order byte first. DEC HL ; point to location beneath. LD (HL),E ; insert low-order byte. LD DE,L0D94 ; 'pos' addr. JP L04BF ; exit via 'pos' routine. ; ----------------- ; THE 'UFLOAT' WORD ; ----------------- ; (un -- f) ; Converts unsigned single length integer to floating point. ; e.g. 65535 16 bit number converted to 32-bit float 8-bit sign/exponent ; 6-nibble BCD mantissa. $45 6 5 5 3 5 0 L1D50: DEFM "UFLOA" ; 'name field' DEFB 'T' +$80 DEFW L1D21 ; 'link field' L1D58: DEFB $06 ; 'name length field' L1D59: DEFW L1D5B ; 'code field' ; --- L1D5B: RST 18H ; pop word off stack to DE EX DE,HL ; now HL LD BC,$1000 ; count 16 bits, set C to zero. LD D,C LD E,C ; initialize DE to zero. L1D62: ADD HL,HL ; double LD A,E ; ADC A,A ; add carry to low byte DAA ; adjust LD E,A ; LD A,D ; ADC A,A ; add carry to high byte DAA ; adjust LD D,A ; RL C ; pick up overflow DJNZ L1D62 ; loop back for 16 bits RST 10H ; DE to Data stack. LD D,$46 ; exponent byte +6 LD E,C ; low byte RST 10H ; higher word of float to stack. DEC HL ; point to DEC HL ; lower on stack CALL L0740 ; normalize routine. JP (IY) ; to 'next'. ; ------------------- ; THE 'CHARACTER SET' ; ------------------- ; The 96 ASCII character bitmaps are copied to RAM during initialization and ; the 8x8 characters can afterwards be redefined by the user. ; Some ROM space is saved by supplying the blank top line of most characters ; and in case of the middle range (capitals with no descenders) the bottom ; line as well. Only the final copyright symbol is held in ROM as an 8x8 ; character. ; $20 - Character: ' ' CHR$(32) L1D7B: DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 ; $21 - Character: '!' CHR$(33) DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00000000 DEFB %00010000 DEFB %00000000 ; $22 - Character: '"' CHR$(34) DEFB %00100100 DEFB %00100100 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 ; $23 - Character: '#' CHR$(35) DEFB %00100100 DEFB %01111110 DEFB %00100100 DEFB %00100100 DEFB %01111110 DEFB %00100100 DEFB %00000000 ; $24 - Character: '$' CHR$(36) DEFB %00001000 DEFB %00111110 DEFB %00101000 DEFB %00111110 DEFB %00001010 DEFB %00111110 DEFB %00001000 ; $25 - Character: '%' CHR$(37) DEFB %01100010 DEFB %01100100 DEFB %00001000 DEFB %00010000 DEFB %00100110 DEFB %01000110 DEFB %00000000 ; $26 - Character: '&' CHR$(38) DEFB %00010000 DEFB %00101000 DEFB %00010000 DEFB %00101010 DEFB %01000100 DEFB %00111010 DEFB %00000000 ; $27 - Character: ''' CHR$(39) DEFB %00001000 DEFB %00010000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 ; $28 - Character: '(' CHR$(40) DEFB %00000100 DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00000100 DEFB %00000000 ; $29 - Character: ')' CHR$(42) DEFB %00100000 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00100000 DEFB %00000000 ; $2A - Character: '*' CHR$(42) DEFB %00000000 DEFB %00010100 DEFB %00001000 DEFB %00111110 DEFB %00001000 DEFB %00010100 DEFB %00000000 ; $2B - Character: '+' CHR$(43) DEFB %00000000 DEFB %00001000 DEFB %00001000 DEFB %00111110 DEFB %00001000 DEFB %00001000 DEFB %00000000 ; $2C - Character: ',' CHR$(44) DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00001000 DEFB %00001000 DEFB %00010000 ; $2D - Character: '-' CHR$(45) DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00111110 DEFB %00000000 DEFB %00000000 DEFB %00000000 ; $2E - Character: '.' CHR$(46) DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00011000 DEFB %00011000 DEFB %00000000 ; $2F - Character: '/' CHR$(47) DEFB %00000000 DEFB %00000010 DEFB %00000100 DEFB %00001000 DEFB %00010000 DEFB %00100000 DEFB %00000000 ; $30 - Character: '0' CHR$(48) DEFB %00111100 DEFB %01000110 DEFB %01001010 DEFB %01010010 DEFB %01100010 DEFB %00111100 DEFB %00000000 ; $31 - Character: '1' CHR$(49) DEFB %00011000 DEFB %00101000 DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00111110 DEFB %00000000 ; $32 - Character: '2' CHR$(50) DEFB %00111100 DEFB %01000010 DEFB %00000010 DEFB %00111100 DEFB %01000000 DEFB %01111110 DEFB %00000000 ; $33 - Character: '3' CHR$(51) DEFB %00111100 DEFB %01000010 DEFB %00001100 DEFB %00000010 DEFB %01000010 DEFB %00111100 DEFB %00000000 ; $34 - Character: '4' CHR$(52) DEFB %00001000 DEFB %00011000 DEFB %00101000 DEFB %01001000 DEFB %01111110 DEFB %00001000 DEFB %00000000 ; $35 - Character: '5' CHR$(53) DEFB %01111110 DEFB %01000000 DEFB %01111100 DEFB %00000010 DEFB %01000010 DEFB %00111100 DEFB %00000000 ; $36 - Character: '6' CHR$(54) DEFB %00111100 DEFB %01000000 DEFB %01111100 DEFB %01000010 DEFB %01000010 DEFB %00111100 DEFB %00000000 ; $37 - Character: '7' CHR$(55) DEFB %01111110 DEFB %00000010 DEFB %00000100 DEFB %00001000 DEFB %00010000 DEFB %00010000 DEFB %00000000 ; $38 - Character: '8' CHR$(56) DEFB %00111100 DEFB %01000010 DEFB %00111100 DEFB %01000010 DEFB %01000010 DEFB %00111100 DEFB %00000000 ; $39 - Character: '9' CHR$(57) DEFB %00111100 DEFB %01000010 DEFB %01000010 DEFB %00111110 DEFB %00000010 DEFB %00111100 DEFB %00000000 ; $3A - Character: ':' CHR$(58) DEFB %00000000 DEFB %00000000 DEFB %00010000 DEFB %00000000 DEFB %00000000 DEFB %00010000 DEFB %00000000 ; $3B - Character: ';' CHR$(59) DEFB %00000000 DEFB %00010000 DEFB %00000000 DEFB %00000000 DEFB %00010000 DEFB %00010000 DEFB %00100000 ; $3C - Character: '<' CHR$(60) DEFB %00000000 DEFB %00000100 DEFB %00001000 DEFB %00010000 DEFB %00001000 DEFB %00000100 DEFB %00000000 ; $3D - Character: '=' CHR$(61) DEFB %00000000 DEFB %00000000 DEFB %00111110 DEFB %00000000 DEFB %00111110 DEFB %00000000 DEFB %00000000 ; $3E - Character: '>' CHR$(62) DEFB %00000000 DEFB %00010000 DEFB %00001000 DEFB %00000100 DEFB %00001000 DEFB %00010000 DEFB %00000000 ; $3F - Character: '?' CHR$(63) DEFB %00111100 DEFB %01000010 DEFB %00000100 DEFB %00001000 DEFB %00000000 DEFB %00001000 ; $40 - Character: '@' CHR$(64) DEFB %00111100 DEFB %01001010 DEFB %01010110 DEFB %01011110 DEFB %01000000 DEFB %00111100 ; $41 - Character: 'A' CHR$(65) DEFB %00111100 DEFB %01000010 DEFB %01000010 DEFB %01111110 DEFB %01000010 DEFB %01000010 ; $42 - Character: 'B' CHR$(66) DEFB %01111100 DEFB %01000010 DEFB %01111100 DEFB %01000010 DEFB %01000010 DEFB %01111100 ; $43 - Character: 'C' CHR$(67) DEFB %00111100 DEFB %01000010 DEFB %01000000 DEFB %01000000 DEFB %01000010 DEFB %00111100 ; $44 - Character: 'D' CHR$(68) DEFB %01111000 DEFB %01000100 DEFB %01000010 DEFB %01000010 DEFB %01000100 DEFB %01111000 ; $45 - Character: 'E' CHR$(69) DEFB %01111110 DEFB %01000000 DEFB %01111100 DEFB %01000000 DEFB %01000000 DEFB %01111110 ; $46 - Character: 'F' CHR$(70) DEFB %01111110 DEFB %01000000 DEFB %01111100 DEFB %01000000 DEFB %01000000 DEFB %01000000 ; $47 - Character: 'G' CHR$(71) DEFB %00111100 DEFB %01000010 DEFB %01000000 DEFB %01001110 DEFB %01000010 DEFB %00111100 ; $48 - Character: 'H' CHR$(72) DEFB %01000010 DEFB %01000010 DEFB %01111110 DEFB %01000010 DEFB %01000010 DEFB %01000010 ; $49 - Character: 'I' CHR$(73) DEFB %00111110 DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00111110 ; $4A - Character: 'J' CHR$(74) DEFB %00000010 DEFB %00000010 DEFB %00000010 DEFB %01000010 DEFB %01000010 DEFB %00111100 ; $4B - Character: 'K' CHR$(75) DEFB %01000100 DEFB %01001000 DEFB %01110000 DEFB %01001000 DEFB %01000100 DEFB %01000010 ; $4C - Character: 'L' CHR$(76) DEFB %01000000 DEFB %01000000 DEFB %01000000 DEFB %01000000 DEFB %01000000 DEFB %01111110 ; $4D - Character: 'M' CHR$(77) DEFB %01000010 DEFB %01100110 DEFB %01011010 DEFB %01000010 DEFB %01000010 DEFB %01000010 ; $4E - Character: 'N' CHR$(78) DEFB %01000010 DEFB %01100010 DEFB %01010010 DEFB %01001010 DEFB %01000110 DEFB %01000010 ; $4F - Character: 'O' CHR$(79) DEFB %00111100 DEFB %01000010 DEFB %01000010 DEFB %01000010 DEFB %01000010 DEFB %00111100 ; $50 - Character: 'P' CHR$(80) DEFB %01111100 DEFB %01000010 DEFB %01000010 DEFB %01111100 DEFB %01000000 DEFB %01000000 ; $51 - Character: 'Q' CHR$(81) DEFB %00111100 DEFB %01000010 DEFB %01000010 DEFB %01010010 DEFB %01001010 DEFB %00111100 ; $52 - Character: 'R' CHR$(82) DEFB %01111100 DEFB %01000010 DEFB %01000010 DEFB %01111100 DEFB %01000100 DEFB %01000010 ; $53 - Character: 'S' CHR$(83) DEFB %00111100 DEFB %01000000 DEFB %00111100 DEFB %00000010 DEFB %01000010 DEFB %00111100 ; $54 - Character: 'T' CHR$(84) DEFB %11111110 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00010000 ; $55 - Character: 'U' CHR$(85) DEFB %01000010 DEFB %01000010 DEFB %01000010 DEFB %01000010 DEFB %01000010 DEFB %00111110 ; $56 - Character: 'V' CHR$(86) DEFB %01000010 DEFB %01000010 DEFB %01000010 DEFB %01000010 DEFB %00100100 DEFB %00011000 ; $57 - Character: 'W' CHR$(87) DEFB %01000010 DEFB %01000010 DEFB %01000010 DEFB %01000010 DEFB %01011010 DEFB %00100100 ; $58 - Character: 'X' CHR$(88) DEFB %01000010 DEFB %00100100 DEFB %00011000 DEFB %00011000 DEFB %00100100 DEFB %01000010 ; $59 - Character: 'Y' CHR$(89) DEFB %10000010 DEFB %01000100 DEFB %00101000 DEFB %00010000 DEFB %00010000 DEFB %00010000 ; $5A - Character: 'Z' CHR$(90) DEFB %01111110 DEFB %00000100 DEFB %00001000 DEFB %00010000 DEFB %00100000 DEFB %01111110 ; $5B - Character: '[' CHR$(91) DEFB %00001110 DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00001110 ; $5C - Character: '\' CHR$(92) DEFB %00000000 DEFB %01000000 DEFB %00100000 DEFB %00010000 DEFB %00001000 DEFB %00000100 ; $5D - Character: ']' CHR$(93) DEFB %01110000 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %01110000 ; $5E - Character: '^' CHR$(94) DEFB %00010000 DEFB %00111000 DEFB %01010100 DEFB %00010000 DEFB %00010000 DEFB %00010000 ; $5F - Character: '_' CHR$(95) DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %11111111 ; $60 - Character: £ CHR$(96) DEFB %00011100 DEFB %00100010 DEFB %01111000 DEFB %00100000 DEFB %00100000 DEFB %01111110 DEFB %00000000 ; $61 - Character: 'a' CHR$(97) DEFB %00000000 DEFB %00111000 DEFB %00000100 DEFB %00111100 DEFB %01000100 DEFB %00111110 DEFB %00000000 ; $62 - Character: 'b' CHR$(98) DEFB %00100000 DEFB %00100000 DEFB %00111100 DEFB %00100010 DEFB %00100010 DEFB %00111100 DEFB %00000000 ; $63 - Character: 'c' CHR$(99) DEFB %00000000 DEFB %00011100 DEFB %00100000 DEFB %00100000 DEFB %00100000 DEFB %00011100 DEFB %00000000 ; $64 - Character: 'd' CHR$(100) DEFB %00000100 DEFB %00000100 DEFB %00111100 DEFB %01000100 DEFB %01000100 DEFB %00111110 DEFB %00000000 ; $65 - Character: 'e' CHR$(101) DEFB %00000000 DEFB %00111000 DEFB %01000100 DEFB %01111000 DEFB %01000000 DEFB %00111100 DEFB %00000000 ; $66 - Character: 'f' CHR$(102) DEFB %00001100 DEFB %00010000 DEFB %00011000 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00000000 ; $67 - Character: 'g' CHR$(103) DEFB %00000000 DEFB %00111100 DEFB %01000100 DEFB %01000100 DEFB %00111100 DEFB %00000100 DEFB %00111000 ; $68 - Character: 'h' CHR$(104) DEFB %01000000 DEFB %01000000 DEFB %01111000 DEFB %01000100 DEFB %01000100 DEFB %01000100 DEFB %00000000 ; $69 - Character: 'i' CHR$(105) DEFB %00010000 DEFB %00000000 DEFB %00110000 DEFB %00010000 DEFB %00010000 DEFB %00111000 DEFB %00000000 ; $6A - Character: 'j' CHR$(106) DEFB %00000100 DEFB %00000000 DEFB %00000100 DEFB %00000100 DEFB %00000100 DEFB %00100100 DEFB %00011000 ; $6B - Character: 'k' CHR$(107) DEFB %00100000 DEFB %00101000 DEFB %00110000 DEFB %00110000 DEFB %00101000 DEFB %00100100 DEFB %00000000 ; $6C - Character: 'l' CHR$(108) DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00001100 DEFB %00000000 ; $6D - Character: 'm' CHR$(109) DEFB %00000000 DEFB %01101000 DEFB %01010100 DEFB %01010100 DEFB %01010100 DEFB %01010100 DEFB %00000000 ; $6E - Character: 'n' CHR$(110) DEFB %00000000 DEFB %01111000 DEFB %01000100 DEFB %01000100 DEFB %01000100 DEFB %01000100 DEFB %00000000 ; $6F - Character: 'o' CHR$(111) DEFB %00000000 DEFB %00111000 DEFB %01000100 DEFB %01000100 DEFB %01000100 DEFB %00111000 DEFB %00000000 ; $70 - Character: 'p' CHR$(112) DEFB %00000000 DEFB %01111000 DEFB %01000100 DEFB %01000100 DEFB %01111000 DEFB %01000000 DEFB %01000000 ; $71 - Character: 'q' CHR$(113) DEFB %00000000 DEFB %00111100 DEFB %01000100 DEFB %01000100 DEFB %00111100 DEFB %00000100 DEFB %00000110 ; $72 - Character: 'r' CHR$(114) DEFB %00000000 DEFB %00011100 DEFB %00100000 DEFB %00100000 DEFB %00100000 DEFB %00100000 DEFB %00000000 ; $73 - Character: 's' CHR$(115) DEFB %00000000 DEFB %00111000 DEFB %01000000 DEFB %00111000 DEFB %00000100 DEFB %01111000 DEFB %00000000 ; $74 - Character: 't' CHR$(116) DEFB %00010000 DEFB %00111000 DEFB %00010000 DEFB %00010000 DEFB %00010000 DEFB %00001100 DEFB %00000000 ; $75 - Character: 'u' CHR$(117) DEFB %00000000 DEFB %01000100 DEFB %01000100 DEFB %01000100 DEFB %01000100 DEFB %00111100 DEFB %00000000 ; $76 - Character: 'v' CHR$(118) DEFB %00000000 DEFB %01000100 DEFB %01000100 DEFB %00101000 DEFB %00101000 DEFB %00010000 DEFB %00000000 ; $77 - Character: 'w' CHR$(119) DEFB %00000000 DEFB %01000100 DEFB %01010100 DEFB %01010100 DEFB %01010100 DEFB %00101000 DEFB %00000000 ; $78 - Character: 'x' CHR$(120) DEFB %00000000 DEFB %01000100 DEFB %00101000 DEFB %00010000 DEFB %00101000 DEFB %01000100 DEFB %00000000 ; $79 - Character: 'y' CHR$(121) DEFB %00000000 DEFB %01000100 DEFB %01000100 DEFB %01000100 DEFB %00111100 DEFB %00000100 DEFB %00111000 ; $7A - Character: 'z' CHR$(122) DEFB %00000000 DEFB %01111100 DEFB %00001000 DEFB %00010000 DEFB %00100000 DEFB %01111100 DEFB %00000000 ; $7B - Character: '{' CHR$(123) DEFB %00001110 DEFB %00001000 DEFB %00110000 DEFB %00110000 DEFB %00001000 DEFB %00001110 DEFB %00000000 ; $7C - Character: '|' CHR$(124) DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00001000 DEFB %00000000 ; $7D - Character: '}' CHR$(125) DEFB %01110000 DEFB %00010000 DEFB %00001100 DEFB %00001100 DEFB %00010000 DEFB %01110000 DEFB %00000000 ; $7E - Character: '~' CHR$(126) DEFB %00110010 DEFB %01001100 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 DEFB %00000000 ; $7F - Character: © CHR$(127) DEFB %00111100 DEFB %01000010 DEFB %10011001 DEFB %10100001 DEFB %10100001 DEFB %10011001 DEFB %01000010 L1 FFB: DEFB %00111100 ; --------------- ; THE 'SPARE' ROM ; --------------- L1FFC: DEFB $FF ; unused ; ---------- ; THE 'LINK' ; ---------- ; The FORTH word copied to RAM links back to L1FFF L1FFD: DEFW L1D58 ; pointer to prev - UFLOAT L1FFF: DEFB $00 ; length of dummy word zero .END ; ----------- ; ; ----------- ; ---------------------- ; THE 'SYSTEM VARIABLES' ; ---------------------- ; "Here is a list of system variables. We have given them all names, but that ; is just for ease of reference. The Ace will not recognize these names, ; except for a few, like 'BASE', that are FORTH words. I've written these ; FORTH words in bold type in the usual way." ; ; ; FP_WS $3C00 (15360) 19 bytes used as work space for floating point ; arithmetic. ; ; LISTWS $3C13 (15379) 5 bytes used as workspace by 'LIST' and 'EDIT'. ; ; RAMTOP $3C18 (15384) 2 bytes - the first address past the last ; address in RAM. ; ; HLD $3C1A (15386) 2 bytes. The address of the latest character ; held in the pad by formatted output. ; ('#', 'HOLD' and so on). ; ; SCRPOS $3C1C (15388) 2 bytes. The address of the place in video RAM ; where the next character is to be printed ; (i.e. the 'print position'). ; ; INSCRN $3C1E (15390) 2 bytes. The address of the start of the ; current 'logical line' in the input buffer. ; ; CURSOR $3C20 (15392) 2 bytes. The address of the cursor in the ; input buffer. ; ; ENDBUF $3C22 (15394) 2 bytes. The address of the end of the current ; logical line in the input buffer. ; ; L_HALF $3C24 (15396) 2 bytes. The address of the start of the the ; input buffer. The input buffer itself is stored ; in the video RAM, where you see it. ; ; KEYCOD $3C26 (15398) 1 byte. The ASCII code of the last key pressed. ; ; KEYCNT $3C27 (15399) 1 byte. Used by the routine that reads the ; keyboard. ; ; STATIN $3C28 (15400) 1 byte. Used by the routine that reads the ; keyboard. ; ; EXWRCH $3C29 (15401) 2 bytes. This is normally 0 but it can be ; changed to allow printing to be sent to some ; device other than the screen. ; ; FRAMES $3C2B (15403) 4 bytes. These four bytes form a double length ; integer that counts the time since the Ace was ; switched on in 50ths of a second. ; ; XCOORD $3C2F (15407) 1 byte. The x-coordinate last used by 'PLOT'. ; ; YCOORD $3C30 (15408) 1 byte. The y-coordinate last used by 'PLOT'. ; ; CURRENT $3C31 (15409) 2 bytes. The parameter field address for the ; vocabulary word of the current vocabulary. ; ; CONTEXT $3C33 (15411) 2 bytes. The parameter field address for the ; vocabulary word of the context vocabulary. ; ; VOCLNK $3C35 (15413) 2 bytes. The address of the fourth byte in the ; parameter field - the vocabulary linkage - of ; the vocabulary word of the most recently ; defined vocabulary. ; ; STKBOT $3C37 (15415) 2 bytes. The address of the next byte into ; which anything will be enclosed in the ; dictionary, i.e. one byte past the present end ; of the dictionary. ; 'HERE' is equivalent to 15415 @. ; ; DICT $3C39 (15417) 2 bytes. The address of the length field in the ; newest word in the dictionary. If that length ; field is correctly filled in then DICT may ; be 0. ; ; SPARE $3C3B (15419) 2 bytes. The address of the first byte past the ; top of the stack. ; ; ERR_NO $3C3D (15421) 1 byte. This is usually 255, meaning "no error". ; If 'ABORT' is used, and ERR_NO is between 0 and ; 127, then "ERROR" will be printed out, followed ; by the error number ERR_NO. ; ; FLAGS $3C3E (15422) 1 byte. Shows the state of various parts of the ; system, each bit showing whether something ; particular is happening or not. Some of these ; may be useful. ; ; Bit 2, when 1, shows that there is an incomplete ; definition at the end of the dictionary. ; ; Bit 3, when 1, shows that output is to fed into ; the input buffer. ; ; Bit 4, when 1, shows that the Ace is in ; invisible mode. ; ; Bit 6, when 1, shows that the Ace is in compile ; mode. ; ; BASE $3C3F (15423) 1 byte. The system number base. ; ; ; ; ----------------------------------------------------------------------------- ; --------- ; ------------------------------------------- ; ------------ -------------------------------------------- ; ACE KEYBOARD --------- ; ------------ --------- ; ;+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ ;| ! | | @ | | # | | $ | | % | | & | | ' | | ( | | ) | | _ | ;| 1 []| | 2 []| | 3 []| | 4 []| | 5 []| | 6 []| | 7 []| | 8 | | 9 | | 0 []| ;+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ ; DELETE CAPS INV <= ^ v => GRAPHIC DELETE ; LINE LOCK VIDEO ;+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ ;| | | | | | | < | | > | | [ | | ] | | © | | ; | | " | ;| Q | | W | | E | | R | | T | | Y | | U | | I | | O | | P | ;+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ ; ;+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ ;| ~ | | | | | \ | | { | | } | | ^ | | - | | + | | = | | | ;| A | | S | | D | | F | | G | | H | | J | | K | | L | |ENTER| ;+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ ; ;+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ ;| | | : | | £ | | ? | | / | | * | | , | | . | | SYM | | | ;|SHIFT| | Z | | X | | C | | V | | B | | N | | M | |SHIFT| |SPACE| ;+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ ; ; ; [] mosaic graphic £ currency symbol ; ; ----------------------------------------------------------------------------- |