| Pin |
Signal |
Direction for host |
Description |
| 1 RES |
Out |
Bus Reset signal |
| 3,5,7,9,11,13,15,17 |
DATA BUS |
Bi-directional |
Used for transferring Status, Data and Control information. |
| 19 GND* |
|
Ground |
| 20 Key |
|
An unused pin, which is clipped off at the drive to prevent incorrect cable attachment. |
| 21 AEN |
Out |
Host address enable, which is asserted during a DMA* cycle to disable the decoding of I/O port addresses. |
| 23 /IOW |
Out |
Host I/O write signal for writing data to an I/O port address. |
| 25 /IOR |
Out |
Host I/O read signal for reading data from an I/O port address. |
| 27 /DACK |
Out |
DMA* acknowledge signal asserted in response to the DMA* Request signal. This signal enables DMA* data transfer when either /IOR or /IOW signals are active. |
| 29 DRQ |
In |
DMA* Request asserted by the drive to initiate a DMA* transfer. |
| 31 IRQ |
In |
Interupt Request asserted by the drive to cause an interrupt to the host. |
| 33,35 SA1,SA0 |
Out |
Host I/O address lines 0 and 1 for selecting the drive's I/O ports. |
| 37 /CS |
Out |
Card Select signal asserted by the host to address the drive's I/O ports. |
| 39 /ACTIVE |
In |
Drive Activity signal asserted by the drive when it is processing a command. Can be used to drive an external LED indicator. |
