[vcf-midatlantic] S-100 protoboards

Herb Johnson hjohnson at retrotechnology.info
Fri Jan 14 18:23:45 UTC 2022

>> It's not appreciated, that S-100 PC mount
>> connectors came in two pin-widths between the two rows. Different brands
>> of backplanes used one or the other. It's a gotcha to buy the wrong
>> width connectors for a particular unpopulated backplane. 
>> Regards, Herb Johnson
> It was my understanding that only the Altair backplane had a different row
> spacing for it's connectors. Everything that I have seen since (IMSAI,
> Ithaca, TEI, CompuPro, Cromemco) used the same .250 row spacing.
> Regards, Jeff

Well, maybe I didn't state the situation clearly. It takes a little 
longer to do so, I didn't want to go off on details, on side issues to 
another topic that has already ended. So I'll make a simple point.

There's all kinds of 100 pin connectors one might buy, which won't 
likely be labeled "S-100". You have to measure the pin spacing anyway - 
which for all S-100 cards is 8 pins per inch. .125 inches apart.

So you may as well, check *your particular motherboard* that you are 
buying connectors for, *just* to be sure the the particular connectors 
you are buying, match the pin row-width also. That will be, 
whateverthehell it is, because there were any number of S-100 
card-producers, who made backplanes, with whatever connectors they 

Just check all your measurements, to avoid getting the wrong part. 
That's all I was saying. It's factually been a problem.

Regards again, Herb

Herbert R. Johnson, New Jersey in the USA
http://www.retrotechnology.com OR .net
preserve, recover, restore 1970's computing
email: hjohnson AT retrotechnology DOT com
or try later herbjohnson AT comcast DOT net

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