Vic Basic; The Language Of The Vic - Commodore VIC-20 Programmer's Reference Manual

VIC BASIC: THE LANGUAGE OF
THE VIC
The BASIC computing language is a powerful and easy-to-use
means of communicating instructions to your VIC 20 Personal
Computer. VIC BASIC is the same language used in the
Commodore PET.'CBM line of microcomputers, and is nearly
identical to the BASIC used in most other personal computers.
Learning BASIC now can prepare you to move up to a more
sophisticated computer in the future, and can also give you the
foundation you need to learn other "higher level'1 computing
languages.
If you're a first-time computerist, you'll be pleased to know you
can write your first BASIC program on the VIC within 15 minutes,
using the VIC 20 PERSONAL COMPUTER GUIDE which comes
with the machine. Additional self-teaching aids are available from
Commodore as part of the TEACH YOURSELF PROGRAMMING
SERIES, and classes offered by schools, computer centers and
retail stores can give you a solid grounding in the fundamentals of
BASIC within 4-6 hours.
The VIC BASIC instructions which follow will provide a valuable
reference as you learn to write BASIC, or as you put into practice
the techniques you've already learned. Each entry in the listing
explains how the instruction is used, with practical examples.
Additional programming tips are included in a separate "BASIC
PROGRAMMING TIPS" section.
BASIC has approximately 60 words in its vocabulary and is
surprisingly easy to learn. That doesn't mean you can't keep
improving, however. Like any language, BASIC has its own
''idioms'1 and complexities which you can use to write increasingly
sophisticated programs, VIC BASIC even has a sort ot "slang" in
that you can abbreviate most of the commands by typing the first
letter of the instruction and the SHIFTED second letter. Using
abbreviated commands to write programs makes programming the
VIC fast and convenient. (Note that if you LIST a program written in
abbreviated form, the full-length commands are displayed to help
you read your program.)
In BASIC, all instructions are commonly referred to as
'commands," although technically the BASIC instruction set can
be broken down into several areas . . . which is how we've grouped
them in the following VIC BASIC "vocabulary11 guide. We've
included separate sections on several types of BASIC instructions;
Commands, Statements, Input/Output Statements, Functions,
Numbers and Variables, and Operators.