MMI 6701 bit slice? - test-drb@ccmp.vtda.org

27 Jul 2007

...

Subject: RE: MMI 6701 bit slice?
   From: "Chuck Guzis" <cclist at sydex.com>
   Date: Fri, 27 Jul 2007 08:32:44 -0700
     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>

On 27 Jul 2007 at 6:51, dwight elvey wrote:

  When I worked at Intel, I was responsible for
test of the analog board
 that went with the 3000 series controller board.
 It seemed that even at the time, most of the engineers were
 only digital and something like a PLL or balanced mixer were
 beyond them. 
One thing I recall about the MDS floppy controller boards is that 
they ran hot as a two-buck pistol.  That was probably true of most of 
the bit-slice stuff of the time. 
That and straight 74 (not LS or AS) TTL.  

...
 Around that time, I'd heard something concerning
the Intel 8272 (the 
8271 was apparently a horrible botch) FDC that I've long wondered was 
true or not. 
The 8271 was single density only and at the time the market wanted DD.
Worked ok but wrong part too late.

...

I'd heard that Intel started development on the 8272, but couldn't 
quite pull it off, and traded the basic design to NEC in exchange for 
NEC's graphics controller.  NEC completed the design as the uPD 765 
and licensed it back to Intel.  Is there the slightest grain of truth 
to this? 
No.  765 was a NEC design and licensed to Intel. There were some IP
trading done between NEC and intel but involved other parts like
7201 (AKA 8274) and others (micros).  Back then the chip makers 
very incestuous. From 79 to mid 80 was a very crazy time.

...
 The 765/8272 in any case was too late for our own
development.  Like 
a lot of other outfits, we went with the gang on Red Hill Road for 
FDCs. 
By then WD had been making functional (usually) 1791/1793 parts for 
two maybe three years.  However, along the way they often would have 
receipe problems and were known to deliver bad parts that would not
work at all.  The 1793 was a complex part for it's time and for WD
 the only thing they did that was more complex was WD16 
(microprogrammed CPU also known as LSI-11).  FYI: SMC created a
varient that didn't have the three voltage needs of the WD part 
that was also socket compatable. 

Allison