28 Nov
2005
28 Nov
'05
7:27 p.m.
From: "Allison" <ajp166 at
bellatlantic.net>
Hi Allison
I'm not contridicting, just pointing out some cases
to support. As I recall, the N* controller also used
the synchronous serial chip. I don't know of a case
that used a async part. All of these were used on
hard sectored disk.
I don't know of any soft sectored that used serial
chips. I suspect that it is because these depended
on using illegal data clocking sequences in order
to mark sectors. This would require more external
circuits.
Dwight
Subject: Re: Pinout for SED9421
From: "Dwight K. Elvey" <dwight.elvey at amd.com>
Date: Mon, 28 Nov 2005 10:46:28 -0800 (PST)
To: cctalk at classiccmp.org
Hi
Besides the HeathKit hard sectored controller board,
used on both the H8 and the H89, Polymorphics also
used a serial chip to do data. In both of these
cases, as you state, they used synchronous serial
chips and not async.
Err, Yes that's what I did say. Sync chips were the norm From: "Allison" <ajp166 at
bellatlantic.net>
> From: woodelf <bfranchuk at
jetnet.ab.ca>
---snip---
Did anybody ever use a serial chip and a data
separater
rather than a floppy disk controler?
Yes, many. usually its a sync chip.
Allison for brewed designs there were not OSI or done with TTL.
Often they were used because WD could not supply or was
not viewed as the desireable item due to lack of second
source (at least early on). Some did it to have a
propritory format.
Allison