Atari 800XL Technical Service Data

1C PINOUTS & TERMINAL GUIDES
SN74LS138N
SELECT
ENABLE
1
2
3
4
5
.6
OUTPUT 7
8
A
VCC
-I
B
B A
YO
YO.
C
C
Y1
Y1
A2A
G2A
Y2
Y2
G2B
G2B
Y3
Y3
G1
G1
- V4
V7 n
Y7 Y6
Y5
Y5
GND
t
Y6
DATA OUTPUTS
DECODER/DEMULTIPLEXER
TOP VIEW
SN74LS158N
SELECT
INPUTS
3r
INPUTS
OUTPUT 4
5
6
OUTPUT 7
8
GNO
1A
S
G
IB 4A
1Y 4B
2A
4Y
2B 3A
2Y
3Y
3B
VCC
STROBE
1
1
14
13
12 OUTPUT
INPUTS
INPUT
9 OUTPUT
U26, U27
RAM ADDRESS MULTIPLEXER
TOP VIEW
NCR2364-30
BASIC ROM
TOP VIEW
SN74LS37SN
M38128A43
1
VPP
VCC
2
A12
PGM
3
A7
A13
4
A6
AS
5 A5
A9
6 A4
All
7
A3
OE
8
A2
A10
9
A1 CE
10
A0
D7
11
DO
D6
12
01
D5
13
D2
04
14
GND
03
U5
OPERATING SYSTEM ROM
TOP VIEW
_D1_
VCC
_Ql_
~n
D4
Oi_
04
El. 2
Q4
Q2
E3. 4
02
_03
02
_03_
GND
_T_J
—
U28
LATCH
TOP VIEW
6502C
f- "L/ -—-
•
nooio-oi
1100084)1
R6520E
1
VCC
RES
40
1
GNO
02
40
1
A1
A2
40
l GND
CAl
40
2
RDY
02 OUT
39
2 D3
01
39 2
A0
A3
39
2
PAO
CA2
39
3
01 OUT
SO
38
3
D4
D0
38
3
GND
A4
38
3
PA!
IRQA
38
4
IRQ
0 OIN
37
4 05 AUDIO
37 4
D3
D4
37
4
PA2
iRQl
37
5
NC m 36
5
D6 A0 36 5
D2 D5 36
5
PA3
Al
36
6
NMi
HALT
35
6
07 A1 35 6
D1
D6
35
6
PA4
AO
35
7
SYNC
NC
34
7
02
A2 34
7 00 D7 34
7
PAS
RES 34
S, VCC DO 33
8
PS A3
33
8
T0
R/W 33
*1 PAfi
DO
33
9
AO
D1 32
9
P7
R/W
32
9
T]
CS
32
9
PA7
D1 32
10
A1
D2
31
10
P4
CS1 31
10
T2
LUM3
3!
10
PBO
D2
31
11 A2
D3
30
11
P5 CS0
30
11
T3
02 30
11
PBl
D3 30
12
A3
04
29
12
P2
iRQ
29 12
S0 F0O 29
12
PB2
D4
29
13
A4
05
28
13
P3
SOD
28 13
Si
OSC
28
13
PB3
D5 28
14 A5
D6
27
14
P0
ACLK
27
14
S2
VCC
27
14
PB4
D6
27
15
A6 D7
26
15
PI
BCLK
26
15
S3
HALT
26
15
PBS
D7 26
16 A7 A15 25
16
KR2 KR!
25 16
PAL
C SYNC
25
16
PB6
02
25
17
A8
A14
24
17
VCC SID
24 17
CADJ
LUM 2
24
17
PB7
CS1 24
18
A9
A13
23
18
K5.
K0
23
18
AN0
LUM 1
23
18 CB1
CS2
23
19
A10
A12 22
19
K4
iTi 22
19
AN1
LUM 0
22
19
CB2
CSO
22
20
All
GND
21
20
K3
K2
21
20
AN2
COL
2 1
20
VCC
R/W
21
III!
CPU
TOP VIEW
U22
POKEY
TOP VIEW
U17
GTIA
TOP VIEW
U23
PIA
TOP VIEW
HD74LS51P
AND/OR INVERT GATE
TOP VIEW
3 37
336
335
334
333
P n
[17
TOP VIEW
TOP VIEW
P 5
U1
TOP VIEW
2 4 6 8 10 1 ?
^7
6 7 16
J5, J6
FRONT VIEW
1 3 5 7 i) II 13
11
FRONT VIEW
ill!
•m — w — ■ m
2 4 6 8
J9
EDGE VIEW
2
J2
FRONT VIEW
2
77
FRONT VIEW
IS 14 13 12 )1 10 5 8 7 6 5 4 3 ? 1
- i —
SRPN. MLKJHFE DC e*
74
TOP VIEW
E BC
Q! THRU Q5
QT, Q8, Q9
U7
BOTTOM VIEW
6
7 Cl
PD14
12
e:
1729
TOP VIEW
]
2
3
4
5
6
7
E
ID
11
12
0
14
15
16
17
li
14
2D
21
22
23
2*
” 1
78
TOP VIEW
HM4864P2
“' LJ_
NC GNO
DIN
CAS
WE
DOUT
RAS A6
AO
A3
A2
A4
Al
A5
VDO
A7
U9 THRU U16
RAM
TOP VIEW
MC14051BCP
IN/OUT
IN/OUT
Y4 --
_l_
Y6
2
m
V
y a
Y5
Y3
E
■
VEE
■
—i—
H
L GH0 ■ —
U24, U25
KEYBOARD MULTIPLEXER
TOP VIEW
IN/OUT

Atari 800XL Specifications

General

Manufacturer	Atari
Type	Home computer
Release year	1983
CPU	MOS Technology 6502C
RAM	64 KB
ROM	24 KB
Operating System	Atari OS
CPU Speed	1.79 MHz (NTSC) / 1.77 MHz (PAL)
Graphics	ANTIC and GTIA chips
Display resolution	160×192 to 320×192 pixels
Sound	POKEY chip
Storage	Cassette tape, floppy disk
Ports	Serial, parallel, monitor, joystick ports