Atari 800 User Manual

120 User's Handbook to the Atari 400 /8 00 Computers
is 1, and the final value is 100. The counter is incremented by 1
each
time the loop is executed, so the loop will be executed 100
times. Lines 30 and 40 both appear inside the loop (between FOR
and NEXT). As a result, lines 30 and 40 are repeated 100 times.
Each time line 30 is executed, an integer between 0 and 255 is
assigned to the variable X. Line 40 prints the character that has
the ASCII code specified by X. Line 60 closes the I/ O channel.
GET is used with the disk in the same fashion as it is used with the
Program Recorder. However the OPEN statement must include a
file specification. The first argument of the OPEN statement is a
channel number. Any channel from 1 to 7 can be used if it is not
already open . The second argument is the operation being
performed. GET can be used with the disk if the OPEN statement
has a second argument of 4 (input) or 12 (input and output). For
example, OPEN #2, 12, O,"D:BUDGET" is a correct OPEN
statement for using GET with a disk. GET assigns the next byte
read
from the disk to the variable specified in the GET statement.
The
GET statement can also be used with the keyboard. An OPEN
statement must be executed before the GET statement is
encountered. The first argument of the OPEN statement is the
number of a channel that is not already OPEN. The channel
number must be a number from 1 to 7. The second argument of
the OPEN statement must be 4 (input). The third argument is
generally O. The device code "K" is the fourth argument.
With the keyboard, a GET statement causes the program to wait
for one keystroke. When a key (or combination of keys) is
pressed, the ASCII code of the character is assigned to the
variable in the GET statement.
EXAMPLE
10 OPEN #2, 4, 0, "K"
20 GET #2, X
30 PRINT X
40 CLOSE #2
RUN
(PRESS "S")
83

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