Jupiter Ace Resource Site - Software Listing Music

Music

on Jupiter Ace

To start the music program, you must define a variable to set the length of the notes. In this program all notes will be the same length. The variable Qua will be used:

200 VARIABLE QUA
Now you can define the word, Music as: DEFINER MUSIC , DOES> @ QUA @ BEEP ;

This enables you to store the data for the notes in a very efficient way. Now the boring bit - the data is put in as variables thus:

478 music C
426 music D
379 music E
358 music F
319 music G
284 music A
268 music BB (stands for B flat)
239 music C+ (an octave above the other C)
213 music D+
201 music EB+
179 music F+
190 music E+

You can of course define further notes, but these should be sufficient for an example program. Next, a word Part 1 is defined:

: PART1 F G A C+ BB BB D+ C+ C+ F+ E+ F+ C+ A F G A ;
Next a word Part 2:
: PART2 PART1 BB C+ D+ C+ BB A G A F E F G C E G BB A G ;
And a third word:
: PART3 PART2 APART1 D C+ BB AG F C F E F A C+ F+ C+ A F A C+ ;

The word to run this demonstration program is Bach;

: BACH PART3 179 QUA @ 3 * BEEP ;

Typing in Bach should now run the program. If any problems are encountered then a word Scale should solve them.

: SCALE C D E F G A B C+ D+ E+ F+ SCALE ;

which is a clever way of producing an infinite loop (instead of Begin 0 Until, as suggested by the Ace manual) by getting the word to call itself. Scale just gives a repeating scale of notes (until you press Break, so not use Fast mode) so you can decide if a note is badly defined.

This method is more efficient in memory terms than that suggested by the manual and is a useful addition to games. The words can be used inside words as well as in immediate mode.

The program can be slowed down to a more sedate speed by

300 QUA !

which resets the variable Qua.

Music
by Martin Sudworth

Note:

Update the definition of SCALE, when first printed in the magazine the word SCALE called itself and fills up the memory with return addresses. The correct definition of SCALE is:-

: SCALE C D E F G A B C+ D+ E+ F+ R> DROP SCALE ;