Atari 400 Hardware Manual

Use of Player/Missile Graphics
with BASIC, cont.
4. Each player (and its missile) has a color register which
determines its color. These registers can be controlled by
poking to the following locations:
ADDRESS
704
705
706
707
711
COLOR OF
P/M 0
P/M
1
P/M 2
P/M 3
fifth player (if enabled)
Thus a POKE 706,200 will color player 2 green.
5. The P/M bit information (those bytes which actually describe
the shape of the playe~) must be stored in an area where it
will not interfere with BASIC or the operating system. It
must also start at a 2K memory boundary if single line
resolution players are used, or a lK boundary for double line
resolution players.
6. The page number {i.e. number of 256 byte sections of memory)
for the starting address of the P/M information obtained in
step 5 is poked into location 54279.
7. Enable the P/M DMA by a POKE 53277,3.
8. The starting address of each player is obtained by multiplying
the number obtained in step 6 by 256 and then adding the
offset indicated in P/M memory configuration table.
9. The vertical position of the player is determined by its
location in memory. After the initial offset is obtained in
step 8, its height may be defined. Its range on the playfield
is from 32 to 223 in single line resolution and from 16 to 111
in double line resolution. By adding the desired height to
the initial offset, the absolute address of each player is
found. The appropriate bit information for the player can now
be poked into this address.
A-2-

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)