Atari 520ST

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Hard Disk
1
—
Data
0
2
—
Data 1
3
—
Data 2
4
—
Data
3
5
—
Data 4
6
—
Data
5
7
—
Data
6
8
—
Data 7
9
—
Chip Select
10
—
Interrupt Request
1 1
—
Ground
1 2
—
Reset
1
3
—
Ground
10 987654321
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19 18 17 16 15 14 13 12 11
14
—
Acknowledge
1
5
—
Ground
16
—
A1
17
—
Ground
18
—
Read/Write
1
9
—
Data Request
Cartridge
1
3 5 7 9
It
13 15
17
19 21
23
25
27 29 31 33 35 37 39
2 4
6 8 10 12
14 16 18
20 22 24
26 28 30 32 34
36 38 40
1
—
+ 5 VDC 20
—
Address
1
5
2
—
+ 5 VDC
21
—
Address 8
3
—
Data 1
4
22
—
Address
14
4
—
Data 1
5
23
—
Address 7
5
—
Data
1
2
24
—
Address
9
6
—
Data 1
3
25
—
Address
6
7
—
Data 10
26
—
Address 10
8
—
Data
1
1
27
—
Address
5
9
—
Data
8
28
—
Address 12
1
0
—
Data
9
29
—
Address 1
1
1 1
—
Data
6
30
—
Address 4
1
2
—
Data 7
31
—
ROM
Select
3
1
3
—
Data 4
32
—
Address
3
1 4
—
Data
5
33
—
ROM Select
4
1
5
—
Data 2
34
—
Address
2
16
—
Data
3
35
—
Upper
Data Strobe
1
7
—
Data
0
36
—
Address 1
1
8
—
Data 1
37
—
Lower
Data Strobe
19
—
Address
13 38-40
—
Ground