Sold on eBay: Convergent Technologies S/50 a.k.a. Unix PC, AT&T 3B1 Unix Workstation

dwight dkelvey at
Mon Jan 15 08:16:03 CST 2018

Years ago, we used one of the Convergent machines. I recall playing rats on it. It had a green screen. It was a 8086 processor and had some Multibus slots in it.

I recall the SA8000 hard disk. It would fail after 20 minutes or so. We sent is back to Shugart for warranty  repair with a complete description of how it needed to run for some time before it failed.

They sent it back still broken. I when to Shugart with the drive and found out that they never even looked at the return sheet they had me fill out. They just replaced the drive belt tested it for 2 minutes and sent it back.

I couldn't wait for them to not fix it again. I bought a replacement transistor for the stepper drive and fixed it my self.

We used them because of the bus slots on the back. I made a DC servo controller to run an XY table.

I had an early version of fig Forth running on it to debug my hardware.


From: cctalk <cctalk-bounces at> on behalf of AJ Palmgren via cctalk <cctalk at>
Sent: Sunday, January 14, 2018 6:05:55 PM
To: Todd Goodman
Cc: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Sold on eBay: Convergent Technologies S/50 a.k.a. Unix PC, AT&T 3B1 Unix Workstation

Todd, thanks so much for sharing, and I'm thrilled to know that a member of
this community is where it's going.

May I ask, what are your plans for archival of the included disks and
manuals, if any?

I'd also be quite curious to see if there are any internal circuit
differences between that machine and a "regular AT&T 3b1.  If you ever open
it up, I'd love to see/hear about that.

I've put a fair amount of effort into preserving Convergent-branded OS and
programs, particularly from this era, solely out of personal interest.
Mostly for the MightyFrame, but my journey had to start with the AT&T UNIX
PC first, as that had the larger "still available" user group for learning
& support before I could revers-engineer how to get a MightyFrame to boot.

Anyway, I would really love to see those software/manual sets be preserved
in a / fashion, and if there is anything that I
might be able to do to assist in that effort, I'd love to volunteer.

My site for preserving this area of Convergent software and equipment is at

Please let me know how I might help, in any way.

Thanks so much!

On Sun, Jan 14, 2018 at 8:26 AM, Todd Goodman <tsg at> wrote:

> Hi AJ (and list),
> I got that one.
> Todd
> On 1/13/2018 10:02 PM, AJ Palmgren via cctalk wrote:
>> I'm just wondering if anybody here did (or knows who) bought this one.
>> Even though these were all manufactured by Convergent Technologies, this
>> one is actually BRANDED by Convergent, as their model S/50.
>> And there's software included here. I tried to buy myself, but just missed
>> it.
>> I'd really like to connect with the buyer here, to see if we can do a more
>> expansive documentation project on this machine, as well as an archival of
>> the software that was included.
>> As far as I know, this is the only Convergent S/50 I've ever seen that has
>> survived, especially with all the CONVERGENT software and manuals (vs the
>> AT&T ones)!
>> Thanks!
>> -AJ


AJ Palmgren

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