Atari 400 Field Service Manual

Color Television
Interface
Adaptor
The
Color
Television
Interface Adaptor
(CTIA)
chip
retrieves
graphics
data
from
memory
vU the
ANTTC
DMA
process-
This
data
is routed
to
the
CTIA
eraohics
registers. Figure 1-5
illustrates the
pin
assignments
for
the
CTIA
and GTIA,
Address
Bus
Address
Bus
Ground
Data
Bus
Data Bus
Data
Bus
Data
Bus
Trigger
Trigger
1
Trigger
2
Trigger
3
Console
Sw
Console
Sw
1
Console
SW
2
Console
SW
3
PAL
Color
Delay
Color
Delay
Alphanum.
Data
Alphanum.
Data
1
Alphanum.
Data
2
Al
1
A^
2
V5S
3
D3
4
D2
5
Dl
6
00
7
T^
S
Tl
9
T2
10
T3
11
5^
12
SI
13
S2
1*
S3
13
PAL
16
DEL
17
ANO
IS
ANl
19
AN2
20
*0
A2
39
A3
38
A*
37
D*
36
D5
35
D6
3*
D7
33
R/W
321
C5I
31
CS2
30
PH2
29
FPHO
23
OSC
27
VDD
26
hAlT
25
-
CSYNC
21-
LUM2
23
LUM
1
22
LUM
2
21
COL
Address
Bus
Address
Bus
Address
Bus
Data
Bus
Data Bus
Data Bus
Data
Bus
Read/Write
Chip
Select
1
Chip
Select
2
Phase
2 Input
Clock
Out
Oscillator
Input
Power
HALT
Output
Sync
Luminance
2
Output
Luminance
1 Output
Luminance
Output
"Color
Figure
1-5.
CTTA/GTIA
Pin
Assignments
Graphics
Television
Interface
Adaptor
The
Graphic
Television
Interface
Adaptor
(GTIA)
is
an extended
capabilities
version
of
the CTIA,
having
additional
high-resolution
modes-
I/O
Decoder
The I/O
Decoder
integrated
circuit
(ZiOl)
is a
one-eight
decoder
demultiplexer.
The
Iv^?^®^®^
"
**
^"^*^
'^
*® *^°
^<^ 200' but is
labeled
ZlOl
in the
800
Console
and
Z1Q5
in
the
WO
Console.
Composite
Video
J^^.'tP^T
,^?
^.°°
Motherboards
route
the
Composite
video
signals
(COMP
CHROMA,
COMP
LUM,
MOD,
and COMP
VIDEO)
to
the Power
Supply
to build
the RF
videtJ
output.
ATARI
Home
Computers
1-10

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)