Good haul of old pc stuph - test-drb@ccmp.vtda.org

15 Dec 2005

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Subject: Re: Good haul of old pc stuph
   From: "Chuck Guzis" <cclist at sydex.com>
   Date: Thu, 15 Dec 2005 09:43:05 -0800
     To: cctalk at classiccmp.org

On 12/15/2005 at 9:52 AM Allison wrote:

 All it took was a 8bit/16bit trnaslation usinga
pair of latches
and some buffers. the only part of IDE thats actually 16bits 
wide is data transfers, the registers are bytes. The MFM 
controllers of the time had the same register layout.  The 
WD1003 was likely the best known ISA16 (WD1002 was the ISA8
version) controller for MFM and it's just like talking to 
an IDE drive. 
Quite a number of the early IDE drives would also support 8 bit data
transfers if IOCS16- wasn't pulled low.  Somewhere on the web, there's a
site from someone who's compiled a list of these.   Many early sound cards
included an extra IDE port for the purpose of hooking up a CD drive. 
List them, please.  I've found only two flavors of 3.5" IDE from WD and 
thats it.  Best I've seen is it was spec'd in but almost never implmented.

I have a large (n>20) selection of 500mb and smaller down to 20mb IDE 
drives and it's amazing so few that support 8bit data.

Allison