Contents
Introduction
Chapter 1
 SETTING UP THE ACE
Chapter 2
 SETTING UP THE ACE
Chapter 3
 LOADING PROGRAMS FROM TAPE
Chapter 4
 DEFINING NEW WORDS
Chapter 5
 SIMPLE ARITHMETIC
Chapter 6
 DEFINING NEW ARITHMETIC WORDS
Chapter 7
 ALTERING WORD DEFINITIONS
Chapter 8
 WORDS THAT ARE REALLY NUMBERS
Chapter 9
 MAKING DECISIONS
Chapter 10
 REPEATING
Chapter 11
 SOUND
Chapter 12
 THE CHARACTER SET
Chapter 13
 PLOTTING GRAPHS
Chapter 14
 SAVING PROGRAMS ON TAPE
Chapter 15
 FRACTIONS AND DECIMAL POINTS
Chapter 16
 READING THE KEYBOARD
Chapter 17
 OTHER WAYS OF COUNTING
Chapter 18
 BOOLEAN OPERATIONS
Chapter 19
 MORE ADVANCED ARITHMETIC
Chapter 20
 INSIDE THE DICTIONARY
Chapter 21
 STRINGS AND ARRAYS
Chapter 22
 VOCABULARIES
Chapter 23
 INSIDE COLON DEFINITIONS
Chapter 24
 HOW THE MEMORY IS LAID OUT
Chapter 25
 MACHINE CODE
Chapter 26
 EXTENDING THE ACE
Appendix A
 QUICK GUIDE FOR 'FORTH' ENTHUSIASTS
Appendix B
 ERRORS
Appendix C
 THE JUPITER ACE - FOR REFERENCE
Appendix D
 QUICK GUIDE FOR 'FORTH' ENTHUSIASTS
INDEX

Chapter 1

SETTING UP THE ACE

This manual is delivered with a few accessories, which you should check:

1. A Jupiter Ace computer.

2. A mains adaptor, which converts mains electricity into a low voltage suitable for the Ace. It will work properly only in certain countries (normally including the one to which the Ace was delivered), so if you take your Ace abroad you may need a different mains adaptor. The mains adaptor is a heavy plastic box, three or four inches in size, and extending from it is a lead with a jack plug at the end.

3. A video lead. This is a single coaxial lead with a phono plug at one end and an aerial plug at the other. It is used to connect the Ace to a television.

4. A pair of leads with jack plugs at both ends, used to connect the Ace to a cassette tape recorder. The plugs are colour-coded, so that you can tell the two leads apart.

You will need to provide for yourself a mains electricity supply and a television, which must work on a 625 line 50Hz UHF system. (This is how most televisions in Britain work, but there are some older ones that don't. If your television can receive BBC2 then it should work with the Ace.)
 Later you will need a cassette tape recorder and tape, but these aren't immediately necessary.  Having collected all these, plug the mains adaptor into the mains and switch on there, and plug its jack plug into the socket on the left-hand side of the Ace marked (underneath) 'POWER'. There is no switch on the Ace, so as soon as you do this it starts working. However, you won't know what it's doing until you connect it to the television, so that's the next step.
 Somewhere at the back of the television there should be a socket where the aerial plugs in; but instead of the usual aerial, you must plug in the video lead from the computer. Only one end will fit properly; the other end plugs in to the socket on the right-hand side of the Ace marked 'TV'
 Now plug the television into the mains (unless it uses batteries, of course), switch it on, turn its volume right down, and tune it to channel 36 UHF. (If it uses buttons to select the different channels, you'll have to pick one of these and find a way of tuning it in to the computer.)
 When you've tuned it just right the screen will be a uniform dark grey, except for a small white square near the bottom left-hand corner.

(Now you've set it up, you can start pressing a few keys at random on the Ace keyboard, just to see what happens. You can always get back to the starting position by momentarily disconnecting the power supply from the Ace.)
 The Ace understands a powerful computing language called FORTH. FORTH was invented around 1970 by Charles Moore, and was chosen for the Ace because of its speed, its economical use of computer memory, and the way a few simple concepts give an elegant power to the whole language.  If you already know about FORTH then you will use this manual largely for reference. Chapter 2 describes the input buffer, and Appendix D describes the principle features unique to Ace FORTH.
 If you know nothing about FORTH but you want to learn how to use it, then this manual is for you. Start at the beginning and work right the way through. The exercises at the end of each chapter often make interesting points that the main part of the chapter doesn't cover so don't overlook them even if you don't feel like doing them.
 There remains a third group of Ace owners who aren't interested at all in programming it, but who have bought other people's programs on cassette tape and want to be able to run them. If you're in this third group, Chapters 2 and 3 should be enough to get you going.