Atari 400 Basic Reference Manual page 9

TERMINOLOGY
1
GENERAL
INFORMATION
This section explains BASIC terminology, special notations, and abbreviations
used in this manual, and the special keys on the AT ARI 400™ and AT ARI 800™
Personal Computer Systems keyboard.
It
also points to other sections where
BASIC commands deal with specific applications.
BASIC: Beginner's All-purpose Symbolic Instruction Code.
BASIC Keyword: Any reserved word "legal" in the BASIC language. May be
used in a statement, as a command, or for any other purpose. (See Appendix A
for a list of all "reserved words" or keywords in AT ARI BASIC.)
BASIC Statement: Usually begins with a keyword, like LET, PRINT, or
RUN.
Constant: A constant is a value expressed as a number rather than represented
by a variable name. For example, in the statement X
=
100, X is a v ariable and
100 is a constant. (See Variable.)
Command String:
Multiple commands (or progra m statem ents) placed on the
same numbered line separated by colons.
Expression: An expression is imy legal combina tion of variables, constants,
operators, and functions used together to compute a value. Expressions can be
either arithmetic, logical, or string.
Function: A function is a computation built into the computer so that it can be
called for by the user's program. A function is NOT a statement; it is part of an
expression.
It
is r eally a subroutine used to compute a value which is then
"returned" to the main program when the subroutine returns. COS (Cosine),
RND (random), FRE (unused memory space), and INT (integer) are examples of
functions . In many cases the value is simply assigned to a variable (stor ed in a
variable) for later use. In other cases it may b e printed out on the screen im-
mediately. See Section 6 for more on functions. Examples of functions as they
might appear in programs are:
10 PF.:HH
F.l[l( 0)
(print out the random
number returned)
(add the value re-
returned to 100 a nd
store t he total in
variable X)
General Info rmatio n
1