Atari 400 Basic Reference Manual

ARITHMETIC
FUNCTIONS
ABS
CLOG
EXP
INT
6
FUNCTION
LIBRARY
This section describes the arithmetic, trigonometric, and special purpose func -
tions incorporated into the ATARI BASIC. A function performs a computation
and returns the result (usually a number) for either a print-out or additional
computational use. Included in the trigonometric functions are two statements,
radians (RAD) and degrees (DEG), that are frequently used with trigonometri c
functions. Each function described in this section may be used in either Direct
or Deferred mode. Multiple functions are perfectly legal.
The following functions and statements are described in this section:
ABS ATN ADR
CLOG cos
FRE
EXP SIN PEEK
INT DEG / RAD
POKE
LOG
USR
RND
SGN
SQR
Format: ABS(aexp)
Example:
100 AB = ABS (- 190)
Returns the absolute value of a number without regard to whether it is positive
or negative. The returned value is always positive.
Format: CLOG (aexp)
Example:
100 C = CLOG(83)
Returns the logarithm to the base 10 of the variable or expression in paren-
theses. CLOG(O) should give an error and CLOG(1) should be 0.
Format: EXP (aexp)
Example:
100 PRINT EXP(3)
Returns the value ofe (approximately 2.71828283), raised to the power specified
by the expression in parentheses. In the example given above , the number
returned is 20 .0855365. In some cases , EXP is accu r ate only to s ix signifi cant
digits.
Format: INT (aexp)
Examples: 100 I = INT(3.445)
100 X
= INT(- 14.66778)
(3 would be stored in I)
(-15 would be stored in X)
Function Li brary 33

Atari 400 Specifications

General

Manufacturer	Atari
Model	400
Type	Home Computer
Release Year	1979
CPU	MOS Technology 6502
CPU Speed	1.79 MHz
ROM	10 KB
Operating System	Atari OS
Keyboard	Membrane keyboard
RAM	8 KB (expandable to 48 KB)
Graphics	ANTIC and GTIA chips
Sound	4 channels
Display	RF output for connection to TV
Storage	Optional cassette tape drive or floppy disk drive
Ports	Cartridge
Display Resolution	320x192 (16 colors)