Early Microprocessors in Industrial Microcomputers

steven at malikoff.com steven at malikoff.com
Wed Mar 9 17:13:00 CST 2016

---------------------------- Original Message ----------------------------
Subject: Re: Early Microprocessors in Industrial Microcomputers
From:    "Brent Hilpert" <hilpert at cs.ubc.ca>
Date:    Thu, March 10, 2016 6:49 am
To:      "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>

> On 2016-Mar-09, at 7:28 AM, william degnan wrote:
>> Not a lot is said about early use of microprocessors in industrial
>> microcomputers.  Everything you read about is so home computing oriented,
>> but I believe actual sales would have been greater in the industrial space
>> 1974-77.
> Yes, I'd agree, an overlooked area of tech. development.
> Not limited to industrial micros, I always have my eye out for early (70s period) embedded / end-use / pre-home-computer applications of microprocs.
> Only managed to find a couple pieces of equipment to date. It's the sort of stuff that get's scrapped as it's not recognised or considered for what's inside.
>> I compiled a quick thread on my site about the earliest use of
>> microprocessors in industrial microcomputers on my web site with links to a
>> related article from EDN Microprocessor Design Series Volume II and scans
>> of Process Computer Systems product brochures.  PCS was a pioneer in
>> industrial micro-computing.
>> If anyone has info to share / correct please let me know and I will add to
>> the thread.
>> http://vintagecomputer.net/browse_thread.cfm?id=631
> Looks like a Fairchild F on the two ceramic LSI chips in the photo of the controller board there.
> I don't recall Fairchild as a 2nd source for the 8080 but I'm not sure.
> Doesn't look to be the typical amount of support circuitry for an 8080 system on that board.
> Fairchild F8 system could be a possibility.

I'd go with Brent's suggestion too. The earlier F8 (3850 CPU) was a originally a three chip system,
on the board shown it could possibly be a 3850 CPU at right, the 3851 PSU (Program Strage Unit, it
held the Program Counter, some I/O ports and usually a 1k monitor) at bottom and the top one could
conceivably be a 3853 SMI (Static Memory Interface).
My Fairchild/Mostek F8 Development Kit board is identical to the one shown on the F8 page
https://en.wikipedia.org/wiki/Fairchild_F8 except it has the exact opposite packaging to mine, ie
the 3851 (top in photo) is ceramic and my 3853 (lower left) and 3850 (lower right) are plastic.
There doesn't look to be enough support logic for the 3855  Dynamic Memory Interface. But, this is
all a guess :)

The F8 was used in traffic light controllers, washing machines (AFAIK) and surely a bunch of other
industrial applications.


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