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

[Jules Richardson]

On 11/15/2014 01:52 PM, drlegendre . wrote:
> Oh, and to add to my confusion.. I've read that the early Altair serial
> boards used a 20mA  current-loop transmission standard.. which as far as I
> know, is +not+ standard RS-232 stuff. So should I actually expect this
> board to be a standard RS-232 device, or is it something else.?

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?