Atari 800 User Manual

94 User's Handb ook to the Atari 400/800 Computers
Example
10 X = 3
20 IF X 1\ 2 AND 3 - X THEN END
30 PRINT "X IS EITHER 3 OR 0"
RUN
X
IS EITHER 3 OR 0
This example uses AND in an IF /T HEN statement that ends the
program if X squared and 3 - X both are n ot equal to zero. Since X
is assigned the value 3, the first part of the AND statement equals
3 squared. This
is a logical 1 because 3 squared is non-zero.
However, the second expression, 3 - X, is equal to zero, which is
the logical O. Since EX1 =1 and EX2 =0, the AND state ment is false,
and the next statement is executed (line 30).
ASC
The ASC function returns the ASCII code for the first character of
a string. The argument of ASC ca n be a string variable or
constant.
ATN
CONFIGURATION
X = ASC(a$)
EXAMPLE
10 DIM B$(10)
20 B$ = "ZEBRA"
30 PRINT ASC( B$)
RUN
90
The ATN function returns the arctange nt of the a rgum ent. The
result will be in radians unl ess degrees are specified.

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