HD Controllers - S-100 & Corvus Omninet - test-drb@ccmp.vtda.org

30 Nov 2001

M H Stein &lt;mhstein(a)usa.net&gt; wrote:
...
  Does anybody know anything about the HD interface bus
Cromemco used
 with their early IMI drives (7012 - 8" with transparent cover, 5007,
 5018 & 5021 5 1/2") and the WDI/WDI-II controllers? I'm just curious
 if the same interface was used in any other systems (single 34 pin 
 header, 7 units max, differential servo clock supplied by drive, so 
 it doesn't look like SA1000). 
Yes, Corvus used these drives.  I'd expect Onyx did too; the story is
that the VC who funded IMI also funded Onyx and Corvus so that IMI
would have customers.  It's interesting to know that Cromemco used
them too.

I'm sitting here looking at a photocopy of a data sheet of sorts for
the IMI 7710, and it does provide some description of the interface.
25 signals on a 34-line bus.  I suspect it's somewhere between "more
than I want to type" and "less than you need to know to use the
drive", because I can't quite figure out how you would transfer a
block of data to the drive from what's printed here.

...
  Interesting aside: when Cromemco finally went the
ST506 route with the
 STDC controller, they made a replacement HD board available to convert the 
 IMI 5 1/2" drives to a standard ST506 interface. 
Neat!  

...
  Finally, I also have a Corvus S-100 board; looks like
it might be a 
 host adapter for a disk drive of some sort. Only markings are
 Corvus S-100, 8008 REV K, copyright 1980; 11 TTL chips & a 34 pin
 header. Anybody know what it is and/or want it? 
Yes, that's the Corvus hard disk interface for S-100, p/n
8010-08008-00.  I could be interested in it.

-Frank McConnell