Some special chips

[TerraHertz]

Sorting out some recently acquired old ICs, these interesting ones turned up.



Pretty ceramic and gold packages. I'd thought they must be something special, but no. The two smaller ones are garden variety CMOS 4013. Well I guess they WERE special when made back in the 1970s. The larger one I don't know. 20 legs says it's not an LM3900.  The black specks are dust from ancient anti-statric foam, disintegrating from age. It gets all over everything in the collection.



Then there's this EPROM. It was among a pile I was removing labels and cleaning. It's just an old 2716, but it really is 'special'.
I only noticed its specialness as I was holding it while wiping the top with a tissue soaked in turps to remove the label gum.
Something inside moved! On close inspection it has at least two pieces of debris loose inside, that appear to be a short clipped-off component wire lead, and a drop of solder or something. They are completely loose. If the chip is tilted end up, they sort of disappear under the lip of the ceramic top lid. Holding it level and tapping it gently they bounce around inside. The thin gold bonding wires are looking pretty battered, and maybe some are broken by now.

It had a label on it, so presumably it was in use at some time. I bet that made for an infuriatingly intermittent system, whatever it was.


Lastly, here's one of many sheets of old black foam with ICs. Spot the mistake someone had made. There's a lot of this kind of mixup in the collection. Someone didn't really know their part numberings lore...

[PA0PBZ]

Yeah I learned that if it starts with MC it's probably not what you think, and it could be difficult to find out what it is.

[mawyatt]

Those RCA chips bring back fond memories of the early days of CMOS, RCA even had SOS (Silicon On Sapphire) versions for rad-hard environments. Vaguely remember a SOS version of the 1802uP, and recall Huges had an SOS CMOS fab as well.

Thanks for the memories

Best,

[Benta]

The Hi-Rel/Space chips in the first pictures are beautiful, thanks for sharing. Gold-capped or white ceramic... Great!

And yes, mixing Motorola TTL parts with RCA COSMOS parts is NOT the best idea

[Benta]

RCA even had SOS (Silicon On Sapphire) versions for rad-hard environments.

IIRC, Plessey was the expert on SOS rad-hard chips, both as standard product series as well as ASICs.