Atari XL User Manual

156
The Ateri XL Handbook
15397
60
15413
2
15398
2
15414
2
15399 2
15415
2
15400
2
15416
2
15401 2
15417
2
15402
2 15418
2
15403
2
15419
2
15404 2
15420
2
15405
2
15421
65
15406 2
15422 32
15407 2
15423 60
The ANTIC processor reads the display list from
top to bottom and the instructions in it control the
display in that order.
The three 112 instructions at the start of the list
instruct ANTIC to generate three eight-line
display blocks of border colour.
Of the next three bytes, only the first (66) is an
instruction; this tells ANTIC that display memory
starts at the location given in the next two bytes of
the display list. In a 16k machine these numbers
will be as shown and tell ANTIC that display
memory starts at
64 + 256*60 or 15424.
To see that this is the start of display memory, stop
the program and type: -
POKE 15424, 1 (or whatever the address is for
your machine)
You will see an exclamation mark (!) appear in the
top left hand corner of the screen.

Atari XL Specifications

General

Release Year	1983
CPU	MOS Technology 6502C
Graphics	ANTIC, GTIA
Sound	POKEY (4 channels)
Storage	Cassette tape
Ports	Cartridge
Operating System	Atari BASIC
CPU Speed	1.79 MHz
RAM	64 KB