At the time BI came out we (I then was working for a military/aerospace
contractor) were developing a portable military workstation based on a
microvax-II. We briefly considered building our own version on the VME bus
as opposed to Q-bus, when we learned that the BI-bus interface chipset was
the microVax processor set. This would have saved lots of dough and let us
use current generation hardware in place of the obsolete rubbish for which
DEC charged so much dough. Politics doomed that notion, however. The KIM
didn't have a way to float the processor's address bus, nor did it support
prioritized interrupts, both of which were a little-used "big-deal" on the
S-100. The fact that it also didn't support I/O instructions was a real
limitation, though.
Dick
-----Original Message-----
From: allisonp_at_world.std.com <allisonp_at_world.std.com>
To: Discussion re-collecting of classic computers
<classiccmp_at_u.washington.edu>
Date: Monday, June 28, 1999 6:25 AM
Subject: Re: Local bus schedule
>On Sun, 27 Jun 1999 blstuart_at_bellsouth.net wrote:
>
>> In message <199906271535.AA28999_at_world.std.com>, Allison J Parent writes:
>> ><The book also includes a few x to S-100 translator designs.
>> >
>> >KIM to S100 would be useful.
>
That would not be terribly difficult, depending on which direction you
wanted to go. Unfortunately, the KIM didn't produce the appropriate signals
for about half the functions on the S-100. (Neither did many of the CPU's
offered for the S-100) This stood in the way of a successful commercial
product along these lines. Nevertheless, it would have been nice to buy
rather than build a memory card or controller for the KIM.
>
>> The book includes the schematics and a brief technical description
>> of the KIMSI, a commercial KIM to S-100 product. It's covered in
>> Chapter 15, "6502/6800 to S-100 Conversion."
>
>Would it be possible to get a copy of the schematic and minimal text?
>
>> It was open? I could swear I remember a really big stink in
>> the DEC press when the BI was introduced. Of course, this
>> wouldn't be the first time bit-rot affected my historical
>> claims.
>
>It was open but DEC was the sole source for the interface/protocal
>chipset. Hence the stink. It' was never actully locked as a few years
>later there was both a second source and a "open" spec available. The
>fact of the matter is most vendor specific buses tend to be somewat
>closed if by virtue of lack of adoption by third parties.
>
>Allison
>
Received on Mon Jun 28 1999 - 09:34:18 BST