Atari 400 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 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)