One more try - Can you ID this S-100 Serial board?

jwsmobile jws at
Wed Sep 30 23:17:06 CDT 2015

I couldn't spot how they did level shifting to RS232 levels.  The SI 
signal appears to go to a 7400 next to one of the Uarts.

One of the Uarts is one which requires it would seem 12 v as well, but 
it doesn't do the levels for rs232  (AY-3-1015)

I'd need sharper images and possession of the board to peer at it for an 
hour or so to try to figure it out.

Also the edge card space from the dual 50 pin headers seem to be 
suspicious.  i don't have an S100 spec to look at handy, but I was going 
to see if there is any decoding going on, or maybe this is just a buffer 
board to go to another system.  There seems to be a lot of LS244 and so 
forth going on on the way to the edge card connectors, which smells more 
like a buffer board than a serial board.  that is is not populated but 
for the two 10 pin connectors is more interesting.

Maybe someone else will figure out more or know more.


On 9/30/2015 6:22 PM, drlegendre . wrote:
> In fact, I did not. Thanks for the tip! ;-)
> On Wed, Sep 30, 2015 at 8:18 PM, william degnan <billdegnan at>
> wrote:
>> Did you try asking @
>> Bill Degnan
>> twitter: billdeg
>> On Sep 30, 2015 8:52 PM, "drlegendre ." <drlegendre at> wrote:
>>> (Months along, posts to several boards / lists, still no help on this
>> one..
>>> so I'm giving it another shot. I'd really like to use this board)
>>> Been trying to no avail to find any info on this 'MCT' S-100 serial card.
>>> I'm pretty sure the card works, as it came from a previously-working
>> system
>>> - but all documents are missing, and without the info, I have no idea how
>>> to put it to use. Photos are here:
>>> Other than what I believe is an artwork / batch number on the rear, the
>>> only marking is "Assy 105510" on the front silk screen. My hunch is that
>>> this may have been a fairly generic 'OEM' type card which could have been
>>> re-badged and sold under one or more different names. So perhaps the docs
>>> exist under a name other than MCT?
>>> Any help greatly appreciated - thanks!
>>> -Bill

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