Atari 800 User Manual

158 User's Handbook to the Atari 400/ 800 Computers
EXAMPLE
POINT #3 , SECT, BYTE
In the preceding example, the file pointer for the disk file
opened through channel #3 is moved to the sector specified by
the variable, SECT, and byte within that sector specified by the
variable, BYTE.
POKE (pOK.)
The POKE statement is used to store one byte of information in a
particular memory location.
CONFIGURATION
POKE a, b
The first argument of a POKE statement is the memory location.
If a POKE statement specifies a memory location that does not
exist, the POKE statement has no effect. Also, if a POKE
statement specifies a memory location that is part of the ROM ,
the POKE statement has no effect.
The second argument
of a POKE statement is the value that is to
be stored at the specified memory location. The value of the
second
argument represents one byte. As a result, the value must
be an integer between 0 and 255.
If either of the arguments of a POKE statement is not an integer,
it is rounded off. A value error occurs if the memory location
specified is greater than 65535 or the value of the second
argument exceeds
255. A value error also results if either of these
arguments are negative.
If the POKE statement is not used carefully, it can seriously
disrupt the operation of the computer.
Appendix E contains information regarding commonly used
memory locations.

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