Atari 400 Hardware Manual

Player-Missile Base Address (PMBASE) = MSB of address.
Resolution is controlled by bit 4 of DMACTL.
ADDRESS
Two-line
resolution
(hex)
+180
+200
+280
+300
+380
+400
OFFSET
One-line
resolution
(hex)
+300
PMBASE*100(hex)
M
+400
----~~ J-.....;;;lL..-....&...--1~ /
PO
+400
P1
+600
P2
+700
P3
+800
Player-Missile
Vertical screen
map in memory
Missile
Number
TV SCREEN
/
/
/
/
/1
-
POl
I I
I I I
I I I I
... II
M2 •
I I
MO
-
P2
• W'
I I
I I
•
1 P1
~
M1
P31 M3
- - - :--r-1 .;:;..;.....--=~------'
I
I
I
1 Horizontal position
~~for each object is set
independently by 8
horizontal position
registers.
Each section of memory maps directly
onto total height of TV screen.
Object vertical position is determined
only by its location in its section
of memory. One byte of memory equals
1 or 2 television lines vertically.
Figure II. 2
P L A Y E R - M I S S I L E D M A
II.6

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)