IDE cables

These three types of AT Attachment Interface connectors are widely used:

To provide better signal integrity, the 80 wire cable is mandatory for systems using DMA/66 mode. Every even wire is connected to the ground pins in each connector. Used connectors are same as in 40 wire cable.

40pin connector

PinDescription PinDescription
3Data bit 7 4Data bit 8
5Data bit 6 6Data bit 9
7Data bit 5 8Data bit 10
9Data bit 4 10Data bit 11
11Data bit 3 12Data bit 12
13Data bit 2 14Data bit 13
15Data bit 1 16Data bit 14
17Data bit 0 18Data bit 15
19GND 20(key pin, missing)
21DRQ 3 22GND
23-IOW 24GND
25-IOR 26GND
29-DACK 3 30GND
31IRQ 14/15 32-IOCS16
33Addr bit 1 34-PDIAG
35Addr bit 0 36Addr bit 2
37-CS1FX 38-CS3FX
39-DA/SP 40GND

50pin connector

PinDescription PinDescription
AOption selection pin BOption selection pin
COption selection pin DOption selection pin
E(key pin, missing) F(key pin, missing)
Same as the 40pin connector
41+5V (logic) 42+5V (motor)
43GND 44-TYPE (0=ATA)