AUTHOR'S PREFACE



you find something I didn't, good! Please write and let me know.
You can't hurt the machine by POKEing about in memory, although
you may crash any program in memory, so SAVE your program first.
Usually you can salvage it by pushing RESET, hut you may have to
turn off the machine and reboot on occasion. You can learn a lot about
your machine by simply playing around with it.

ABOUT LANGUAGES
The majority of the information here concerns language-independent
locations and can be used regardless of the language you use for your
programming. When the location is language-dependent, such as the
BASIC or DOS areas, I have noted it in the proper section. You may
exert the same control over your Atari in FORTH, Pascal, LISP, or
whatever language you chose. You will obviously have to change the
commands PEEK and POKE to the proper commands of your
language.
BASIC is a good language to start with: you can use it to learn
programming, to explore your computer, to experiment with, and to
have fun with. However, when you are ready to go on, you will have to
learn a more efficient, faster language if you really want to make the
best use of your Atari. Many people choose 6502 machine language
because of its speed.
If you want to stay with a high-level language, I suggest you learn
FORTH. It has some of the speed of machine language code with the
ease of "higher level language" programming.
Computer languages, whichever you use, are quite exact in their
meaning, especially compared to English. Consider that in English, a
fat chance and a slim chance both mean the same thing. Yet POKE,
PUT, and PUSH have very different meanings in computerese.

TEXT KEY
Example: 912-927 390-39F IOCB5
The main memory map shows you the decimal and then the
hexadecimal location, the label (assigned by Atari and used by OS,
DOS or DUP routines), and then comments and description. The label
has no real function; it is merely a mnemonic convenience. Readers
are referred to Stan Kelly-Bootle's delightful book, The Devil's DP
Dictionary (McGraw-Hill Ryerson, 1981), for a full definition of the
word "label". The following abbreviations are also noted in the
comments:
(R)  Read
(W)  Write

Sometimes the functions are different in a particular location, so each
is noted.