Atari 400 Field Service Manual

Table
7-1
CLOCK
CIRCUIT
PIN
NUMBER
21
of JlOl
22
of JlQl
a
of 2.302
9 of 2302
10
of
2302
13
of 2302
37
of A303
S
of
2301
34
of A302
35
of A302
29
of A301
23
of A301
Collector
of
Q102
Collector
of Q104-
7
of
AlOl
25
of A102
BOARD
CPU
CPU
CPU
CPU
CPU
CPU
CPU
CPU
CPU
CPU
CPU
CPU
300
Main
Board
400
Main
Board
400/800
Main
Board
400/aOO
Main
Board
FREQUENCY
1
.789
1 .789
1 .789
1
.739
1
.789
1
.789
1 .140
1,.789
1.
.73
9
3..579
3.,5 79
3.,579
3..5 79
3.
5
79
1.
739
1.
789
SCOPE
CHART
#
*
1
2
2
1
2"
3
4
3
3
5
5
6
6
6
1
1
*
Use
Scope
Waveform
Legend
on
next
illustration
of
waveform.
page
to
see
ATARI
Home
Computer
7-36

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)