Western Digital Host Adaptors

From: Roger Ivie <IVIE_at_cc.usu.edu>
Date: Mon Jul 14 10:55:25 1997

>> I have a few WD-1000 host adaptors, and I need to get some
>> information about them. Western Dig. is of not much help-- their web
>> site dosen't carry docs from that far back.
>>
>> I used to have a chart delineating what controller card was what, but
>> I've since lost it. There aren't PeeCee host adaptors; rather they
>> are the same footprint as a 5.25' floppy drive (actually, one is
>> bigger).
>
>I'm pretty sure that these aren't host adapters; I think they're
>controllers in the traditional SCSI sense. (i.e. you sandwich
>them between the SCSI bus and a MFM or ESDI drive.)

Somewhere I have docs on the WD1002-05 which, IIRC, has a WD1000-compatible
hardware interface. The exception is that the WD1000 supplies a WAIT signal
and the WD1002 doesn't.

"The WD1002-05 has been designed to interface to a Host processor via a
parallel port or CPU bus configurations. The specific signals are compatible
with the WD1000/WD1001 series of Winchester-only controller boards. With the
inclusion of the WD1015, the previous WAIT signal is no longer necessary,
but has been provided for compatability; status information is always
available to the Host for monitoring command progress. When the Busy bit
is set, no other status bits are valid."

The host connector is a 40 pin connector. Of this, all even pins are grounds.
The other pins are:

1 -15 : DAL0 through DAL7 respectively
17-21 : A0 through A2, respectively
23 : CS
25 : WE
27 : RE
29 : Pulled up on the WD1002; this is probably WAIT on the 1000.
31, 33: Not connected
35 : Interrupt request
37 : DMA request
39 : Reset

I suspect the interrupt request, DMA request, and Reset ar all asserted high;
the photocopied manual section I have doesn't make this clear.

The WD1002 is programmed like an IDE controller with an 8-bit data register.
I suspect the WD1000 is as well.

Roger Ivie
ivie_at_cc.usu.edu
Received on Mon Jul 14 1997 - 10:55:25 BST