MCT Serial board mystery - Can you crack the pinout code?

[drlegendre .]

FYI - I put up a couple photos of the board at:

http://nerp.net/~legendre/altair/mct_serial_01.jpg

http://nerp.net/~legendre/altair/mct_serial_02.jpg

On Sat, Nov 15, 2014 at 4:47 PM, drlegendre . <drlegendre at gmail.com> wrote:

> Jules & All,
>
> On Sat, Nov 15, 2014 at 3:18 PM, Jules Richardson <
> jules.richardson99 at gmail.com> wrote:
>
>>
>> Are you even sure that it's intended as a terminal board, rather than for
>> some other peripheral that happens to be serial in nature?
>>
>
> Now why did you have to go and ask +that+? ;-)
>
> No, I guess I don't know for sure, but here's what I do know - the last
> owner did have +some+ way of talking to the system (in its previous
> configuration), and this is the +only+ board in the lot that even comes
> close to resembling a communications card.  The other boards are a Z-80
> CPU, a 64K dynamic RAM and a dual floppy-disk controller.
>
> The Z-80 CPU board does have both serial & parallel I/O edge-connectors on
> it, but they look to have had little to zero use.. maybe one or two
> connection cycles at most, perhaps just one cycle for factory QA testing.
>
> Also, and this was dumb of me, I recall the serial board having a cable
> +soldered+ directly to it. It only had 3 wires which terminated in a 25-pin
> sub-D male connector, with only 3 pins installed. It struck me (like much
> of the system) to have been a careless bodge or hack of some sort, so I
> must have de-soldered it. Now, I can't even locate that cable, or tell
> where it was previously attached.
>