Atari 800 Basic Reference Manual

LOG
RND
SGN
s~
Returns the greatest integer less than or equal to the value of the expression.
This is true whether the expression evaluates to a positive or negative number.
Thus, in our first example above, I is used to store the number 3. In the second
example, X is used to store the number- 15 (the first whole number that is less
than or equal to -14.66778). This INT function should not be confused with the
function used on calculators that simply truncates (cuts off) all decimal places.
Format:
LOG(aexp)
Example:
100 L = LOG(67.89/2.57)
Returns the natural logarithm of the number or expression in parentheses.
LOG(O) should give an error and LOG(1) should be 0.
Format:
RND(aexp)
Example:
10 A=RND (0)
Returns a hardware-generated random number between 0 and 1, but never
returns 1. The variable or expression in parentheses following RND is a dummy
and has no effect on the numbers returned. However, the dummy variable must
be used. Generally, the RND function is used in combination with other BASIC
statements or functions to return a number for games, decision making, and the
like. Here's a simple routine that returns a random number between 0 and 999.
1 0 :~~=~~NO( 0)
20 F.::x:=IHT< 1000:~~:;()
33 PRINT R?i
Format:
SGN(aexp)
Example:
100 X = SGN(-199}
(0 is dummy variabl e)
(-1 would be returned)
Returns a -1 ifaexp evaluates to a neg a tive numbe r; a 0 ifa exp evaluates to 0, or a
1
if aexp evaluates to a positive number.
Format:
SQR(aexp)
Example:
100 PRINT SQR(100) (10 would be printed)
Returns the square root of the aexp which must be positive.
TRIGONOMETRIC
FUNCTIONS
ATN
Format:
ATN(aexp)
Example: 100 X = ATN(65)
Returns the arctangent of the variable or expression in parentheses .
cos
Format: COS( ae xp)
Example: 100 C = COS(X+Y+Z)
Note: Presumes X, Y, Z previously defined !
Returns the trigonometric cosine of the expre ssion in parentheses.
34 F un ct ion Library

Atari 800 Specifications

General

Processor	MOS Technology 6502
Processor Speed	1.79 MHz
ROM	10 KB
Graphics	ANTIC and GTIA chips
Release Year	1979
Display Resolution	up to 320 x 192
Colors	128 colors
Sound	4 channels
Storage	Cartridge, cassette, floppy disk
Ports	Cartridge, serial, monitor
Operating System	Atari OS