IBM HD Controller Pinouts

IBM DBA-ESDI Connector (Model 50, 55, 70, P70, 90, 5560)
IBM SCSI Pinouts (Most later PS/2s)

XT-Bus (8-bit) IDE Connector
IBM XT Bus IDE Connector (Model 25 and 30)
ATA Connector (Lacuna, 9533, 9553)


XT-Bus (8-bit) IDE Connector

PinSignalPinSignal
1-RESET2Ground
3Data Bit 74Ground
5Data Bit 66Ground
7Data Bit 58Ground
9Data Bit 410Ground
11Data Bit 312Ground
13Data Bit 214Ground
15Data Bit 116Ground
17Data Bit 018Ground
19Ground20Key (Missing pin)
21AEN22Ground
23-IOW24Ground
25-IOR26Ground
27-DACK 328Ground
29DRQ 330Ground
31IRQ 532Ground
33Address Bit 134Ground
35Address Bit 036Ground
37-CS1FX38Ground
39-Drive Active40Ground


IBM XT-Bus IDE Connector (PS/2 Model 25 and 30)

PinSignalPinSignal
1-RESET2-Disk Installed
3Data Bit 04Ground
5Data Bit 16Ground
7Data Bit 28Ground
9Data Bit 310Ground
11Data Bit 412Ground
13Data Bit 514Ground
15Data Bit 616Ground
17Data Bit 718Ground
19-IOR20Ground
21-IOW22Ground
23-CS1FX24Ground
25Address Bit 026Ground
27Address Bit 128Ground
29Address Bit 230+5 Vdc
31Reserved32+5 Vdc
33-DACK 334Ground
35DRQ 336Ground
37IRQ 538Ground
39I/O CH RDY40+12 Vdc
41Spare42+12 Vdc
43Spare44+12 Vdc


ATA Connector (Lacuna, 9533, 9553)

PinSignalPinSignal
1-RESET2Ground
3Data Bit 74Data Bit 8
5Data Bit 66Data Bit 9
7Data Bit 58Data Bit 10
9Data Bit 410Data Bit 11
11Data Bit 312Data Bit 12
13Data Bit 214Data Bit 13
15Data Bit 116Data Bit 14
17Data Bit 018Data Bit 15
19Ground20Key (Missing pin)
21DRQ 322Ground
23-IOW24Ground
25-IOR26Ground
27I/O CH RDY28SPSYNC:CSEL
29-DACK 330Ground
31IRQ1432-IOCS16
33Address Bit 134-PDIAG
35Address Bit 036Address Bit 2
37-CS1FX38-CS3FX
39-DA/SP40Ground
41+5 Vdc (Logic)42+5 Vdc (Motor)
43Ground44-Type (0=ATA)

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Louis F. Ohland, Peter H. Wendt, David L. Beem, William R. Walsh, Tatsuo Sunagawa, Tomáš Slavotínek, Jim Shorney, Tim N. Clarke, Kevin Bowling, and many others.

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Last update: 20 Jan 2024 - Changelog | About | Legal & Contact