Help with PCB ID

Cory Heisterkamp coryheisterkamp at
Sat Mar 13 13:43:12 CST 2021

I’m wondering if anyone recognizes this PCB.  Double-sided, 74xx vintage, measuring 14”x15”. There’s a “B.I.” logo in one corner, but no google match. IC date codes are ’77/’78 vintage.

There’s a pair of DB-25’s, a BCD encoder, and for some reason, two pots. DC rectification appears to take place onboard. I thought perhaps the 112-7753 marking might be a part or catalog number, however the flip side is marked 112-1754, so perhaps not.

Anyone recognize it?  -Cory

More information about the cctech mailing list