8-bit IDE

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Tue Apr 18 08:27:01 2000

On Mon, 17 Apr 2000, Richard Erlacher wrote:

> Well, I've got one drive, an ST351, I think it is, that responds to the
> 8-bit conditioning. It's a 1.25"-tall 3-1/2" drive, of 44 MB capacity.
> That's not what I want for the "hard-card" on the S-100.

I have two of them. Never thought to try them as they are slow and very
old.

> All your assertions about the relative folly of expending effort/resources
> to make the drive talk-8-bits wide has no real purpose except to bind it to
> its historical roots. I'd bet that the logic in the 1003-WAH uses the
> data-width bit to enable the IOCS16- signal and thereby lets the AT bus
> control whether the transfer is 8 or 16 bits wide, since the AT bus is
> required to do that.

Flog thyself if you care to. ;) Oh, the 1003WAH DOES NOT respond to
set_16bits. Before I ahd IDE drives to experiment with I tried it.
it still lost every other byte, just didn't generate the signal(IOCS16).
The 1003 was never useable in ISA-8 (xt bus).

What I did do instead was to use a WD1002WXA to make that interface
as it was already ISA-8 and easy to interface as a 8-bit controller.
Wrote an article for TCJ about it.

Allison
Received on Tue Apr 18 2000 - 08:27:01 BST