Commodore Plus 4 - Page 8

vi Preface
announced the Commodore 16, which is compatible with the Plus/4. The Com
modore 16 has only 16 K RAM and no built-in software. The two new computers
are compatible, so all Commodore 16 software and peripherals are compatible
with the Plus/4.
About This Book
The Programmer's Reference Guide for the Commodore Plus/4 is a reference
book for programmers of all levels. The book provides information for both
BASIC and machine language programmers. The authors assume that readers
are familiar with the general operations of the Plus/4 and understand all the
keyboard functions. Neither BASIC nor machine language is taught in this book,
but extensive information is provided on programming in both languages. Pro
grammers of either BASIC or machine language will find the information they
need to write programs for themselves or for commercial distribution.
The authors have written and tested all the programs in this book. (Please note
that the programs are copyrighted and cannot be used for commercial purposes.)
Cyndie Merten, programmer and mathematician, is a founding member of
Dyadic Software Associates, a group of microcomputer consultants. Sarah
Meyer is a free-lance technical writer who has published another book about the
Plus/4. Together they have published several articles about Commodore comput
ers. The authors combine their perspectives as programmer and writer to produce
a book that is thorough, technically accurate, and clearly written. Please note that
Commodore Business Machines, Inc. has not been involved in the preparation of
this book. The authors bear responsibility for the accuracy of the material
presented here.
The Programmer's Reference Guide for the Commodore Plus/4 is divided into
six chapters. The chapters cover BASIC, the built-in software, programming
techniques, machine language, graphics, and peripheral devices. Memory maps
and other technical information are covered in the appendixes.
Chapter 1, The BASIC Language, provides complete descriptions of all 75+
commands, 36 functions, and the system variables that constitute BASIC 3.5. To
simplify looking up BASIC keywords, the elements of BASIC 3.5 are presented
in alphabetical order, with commands, functions, and system variables inter
mixed. For each keyword, the following information is given:
1. The abbreviation (when there is one).
2. A complete syntax, so you can quickly review the order of parameters.
3. A description of all uses for the command or function.
4. An explanation and range of possible values for each parameter.
5. Examples.