XT-Bus (8-bit) IDE Connector
IBM XT Bus IDE Connector (Model 25 and 30)
MCA DBA (Direct Bus Attachment) Hard Drive Connector (Model 50 and 70)
ATA Connector (Lacuna 9577, 9533, 9553)
XT-Bus (8-bit) IDE Connector
Pin | Signal | Pin | Signal |
1 | -RESET | 2 | Ground |
3 | Data Bit 7 | 4 | Ground |
5 | Data Bit 6 | 6 | Ground |
7 | Data Bit 5 | 8 | Ground |
9 | Data Bit 4 | 10 | Ground |
11 | Data Bit 3 | 12 | Ground |
13 | Data Bit 2 | 14 | Ground |
15 | Data Bit 1 | 16 | Ground |
17 | Data Bit 0 | 18 | Ground |
19 | Ground | 20 | Key (Missing pin) |
21 | AEN | 22 | Ground |
23 | -IOW | 24 | Ground |
25 | -IOR | 26 | Ground |
27 | -DACK 3 | 28 | Ground |
29 | DRQ 3 | 30 | Ground |
31 | IRQ 5 | 32 | Ground |
33 | Address Bit 1 | 34 | Ground |
35 | Address Bit 0 | 36 | Ground |
37 | -CS1FX | 38 | Ground |
39 | -Drive Active | 40 | Ground |
IBM XT-Bus IDE Connector (PS/2 Model 25 and 30)
Pin | Signal | Pin | Signal |
1 | -RESET | 2 | -Disk Installed |
3 | Data Bit 0 | 4 | Ground |
5 | Data Bit 1 | 6 | Ground |
7 | Data Bit 2 | 8 | Ground |
9 | Data Bit 3 | 10 | Ground |
11 | Data Bit 4 | 12 | Ground |
13 | Data Bit 5 | 14 | Ground |
15 | Data Bit 6 | 16 | Ground |
17 | Data Bit 7 | 18 | Ground |
19 | -IOR | 20 | Ground |
21 | -IOW | 22 | Ground |
23 | -CS1FX | 24 | Ground |
25 | Address Bit 0 | 26 | Ground |
27 | Address Bit 1 | 28 | Ground |
29 | Address Bit 2 | 30 | +5 Vdc |
31 | Reserved | 32 | +5 Vdc |
33 | -DACK 3 | 34 | Ground |
35 | DRQ 3 | 36 | Ground |
37 | IRQ 5 | 38 | Ground |
39 | I/O CH RDY | 40 | +12 Vdc |
41 | Spare | 42 | +12 Vdc |
43 | Spare | 44 | +12 Vdc |
MCA DBA (Direct Bus Attachment) Hard Drive Connector (Model 50 and 70)
This is a subset of the standard Micro
Channel slot (16-bit version).
Pin | Signal | Pin | Signal |
A1 | -CD SETUP | B1 | Address Bit 15 |
A2 | Address Bit 13 | B2 | Address Bit 14 |
A3 | Ground | B3 | Ground |
A4 | Address Bit 11 | B4 | OSC (14.3 MHz) |
A5 | Address Bit 10 | B5 | Ground |
A6 | Address Bit 9 | B6 | Address Bit 12 |
A7 | +5 Vdc | B7 | -CMD |
A8 | Address Bit 8 | B8 | -CD SFDBK |
A9 | Address Bit 7 | B9 | Ground |
A10 | Address Bit 6 | B10 | Data Bit 1 |
A11 | Ground | B11 | Data Bit 3 |
A12 | Address Bit 5 | B12 | Data Bit 4 |
A13 | Address Bit 4 | B13 | Ground |
A14 | Address Bit 3 | B14 | CHRESET |
A15 | +5 Vdc | B15 | Data Bit 8 |
A16 | Address Bit 2 | B16 | Data Bit 9 |
A17 | Address Bit 1 | B17 | Ground |
A18 | Address Bit 0 | B18 | Data Bit 12 |
A19 | +12 Vdc | B19 | Data Bit 14 |
A20 | -ADL | B20 | Data Bit 15 |
A21 | -PREEMPT | B21 | Ground |
A22 | -BURST | B22 | Data Bit 0 |
A23 | +5 Vdc | B23 | Data Bit 2 |
A24 | ARB 0 | B24 | Data Bit 5 |
A25 | ARB 1 | B25 | Ground |
A26 | ARB 2 | B26 | Data Bit 6 |
A27 | +12 Vdc | B27 | Data Bit 7 |
A28 | ARB 3 | B28 | Data Bit 10 |
A29 | +ARB/-GRANT | B29 | Ground |
A30 | -TC | B30 | Data Bit 11 |
A31 | +5 Vdc | B31 | Data Bit 13 |
A32 | -S0 | B32 | -SBHE |
A33 | -S1 | B33 | Ground |
A34 | +M/-IO | B34 | -CD DS 16 |
A35 | Ground | B35 | -IRQ 14 |
A36 | CD CHRDY | B36 | Ground |
Ed.
Tom: Pin A11 was listed as +5 V DC instead of Ground (see Model 70 TR).
I have measured this on my Model 70, and pin A11 indeed is tied to the ground.
Scott Mueller's Upgrading and Repairing PCs has this error as well!
ATA Connector (Lacuna, 9533, 9553)
Pin | Signal | Pin | Signal |
1 | -RESET | 2 | Ground |
3 | Data Bit 7 | 4 | Data Bit 8 |
5 | Data Bit 6 | 6 | Data Bit 9 |
7 | Data Bit 5 | 8 | Data Bit 10 |
9 | Data Bit 4 | 10 | Data Bit 11 |
11 | Data Bit 3 | 12 | Data Bit 12 |
13 | Data Bit 2 | 14 | Data Bit 13 |
15 | Data Bit 1 | 16 | Data Bit 14 |
17 | Data Bit 0 | 18 | Data Bit 15 |
19 | Ground | 20 | Key (Missing pin) |
21 | DRQ 3 | 22 | Ground |
23 | -IOW | 24 | Ground |
25 | -IOR | 26 | Ground |
27 | I/O CH RDY | 28 | SPSYNC:CSEL |
29 | -DACK 3 | 30 | Ground |
31 | IRQ14 | 32 | -IOCS16 |
33 | Address Bit 1 | 34 | -PDIAG |
35 | Address Bit 0 | 36 | Address Bit 2 |
37 | -CS1FX | 38 | -CS3FX |
39 | -DA/SP | 40 | Ground |
41 | +5 Vdc (Logic) | 42 | +5 Vdc (Motor) |
43 | Ground | 44 | -Type (0=ATA) |
|