Unknown boards

Brent Hilpert bhilpert at shaw.ca
Sat Jun 17 14:44:31 CDT 2017

> On 16/06/2017 19:02, william degnan via cctech wrote:
>> I checked and they are no GE 4000 system boards.
>> On Fri, Jun 16, 2017 at 12:57 PM, Jon Elson via cctech <
>> cctech at classiccmp.org> wrote:
>>> On 06/16/2017 09:31 AM, David Gesswein via cctech wrote:
>>>>     Can anyone identify these boards? Person I got them from can't
>>>> remember
>>>> anything about them.
>>>> http://www.pdp8online.com/ftp/misc/unknown_boards/
>>>> Date codes of 1964. Size 4.5"x3.25". Looks like used card edge for
>>>> keying but has separate 23 pin connector for electrical connection.
>>>> No useful markings I can see. Has card ## on the back.
>>>> Search by picture didn't find anything.
>>>> Thanks
>>>> They remind me of RCA bizmac boards, which are likely to be related to
>>> GE, as that computer division changed hands a number of times.
>>> The connectors are Elco Varilok.
>>> Jon

On 2017-Jun-16, at 9:31 PM, dwight via cctalk wrote:
> The board in the bottom center is 6 buffers or inverters.
> The upper right is 4 flipflops. The upper right is some type
> of decoder( maybe an address or something ).
> The bottom right is a clock generator and the one on the
> lower left looks to be a massive gate, nor or nands depending on the logic used.
> Function is not the issue, what machine used it is the question.
> Dwight

The boards look similar in construction to those in a digital counter from 1961 I have, built by Transistor Specialties Inc.: fiberglass substrate, similar componentry, layout technique, and the Elco edge connectors (those were really nice connectors). Although, other than the edge connectors, a lot of that was similar in that era.
I don't have my website up to link to a pic.

At first glance I thought that was a crystal for a timebase too on the bottom right board, but it's actually a relay.

As Chuck suggests, it strikes me as more or equally likely being from digital test equipment, hard-wired logic controller or such, than being from a computer.
Those were the days of building dedicated logic controllers rather than using a computer, for many tasks.

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