Fairchild µL 92328 ... what is it?

[eccerr0r]

Anyone have any ideas what the Fairchild µL 92328 IC is?

Package: Looks like a half TO-5 can except plastic, dark brown, 8 pins.. Keyed by a flat spot on the circumference.

Assumptions: This is a Logic IC of some ancient technology as it's on a logic board of an ancient digital circuit using RTL 2-input NOR gates, unsure of total function, which would be revealed if i figure out what the µL92328 is.

Closest I got was ECG/NTE that reported it was obsolete... but of course it is...

Appears that people are selling these NOS but no hints at the logic function.

Estimate age: about 55-60 years old.

[redwire]

Re: Fairchild µL 92328 ... what is it?

Fairchild Micrologic series came out in 1961 in metal TO-5, TO-18 8-lead can. I think among the first digital IC's. Outsourced packaging to Hong Kong was another first. Hmmm.
uL923 RTL Dual J-K Flip Flop. Epoxy package must be the early 1970's but not full mil spec. -55 to +125C.
Some gates made it into the Apollo Guidance computer.
https://www.semiconductormuseum.com/..._923_Index.htm
https://spingalhistory.blogspot.com/...first-ics.html

edit: I can't find the suffix codes, "923EC" is epoxy consumer temp range, "28" might be a batch/date code?

[eccerr0r]

Re: Fairchild µL 92328 ... what is it?

Thanks, that was annoying, the actual part number is 923 and not 92328 or 9232... This was clearly in the late 1960s so yep.

It appears to be a single, not dual - 8 pins is not enough pins to squeeze two JK presettable flip flops. DIP16 CD4027 or SN7476 would be necessary...

[redwire]

Re: Fairchild µL 92328 ... what is it?

Oops it is a single flip-flop. Kinda neat seeing an AND gate etc. in a small can package. The tech appears to be the outcome of the Apollo space program where they used RTL, trickled down to people.
Not sure what to make with them, dividers for a discrete digital clock maybe?

[eccerr0r]

Re: Fairchild µL 92328 ... what is it?

Well, the circuit I have was some sort of digital display for some ancient quantitative chemical analysis equipment alas it's parted and disposed of now. I was wondering if I could trace the circuit and add or cut some wire here and there to make something out if the circuit. It already drives 4 NIXIE tubes so must be able to do something with it. Knowing these are JKFFs is a big step, the circuit now is known to have JKFFs, decade counters, NOR gates, and the NIXIE drivers...

[eccerr0r]

Re: Fairchild µL 92328 ... what is it?

Based on the examples I see and the ones I have, the part number is always 92328 -- there is a 3 digit code after the 92328 like -815 which I think is the date code. So the "28" part remains a mystery - it even has a sample 92328 in the datasheet...

My current guess is that the 28 has something related to its plastic case.

I don't think the single gate ICs have gone away, there are those 74AHCT1G00 or something like that, a sot23-5 that has a single NAND gate.

Granted a TO-5/TO-18 is easier to work with than a sot23, maybe a DIP8 would work too.