Old Japanese MOS ICs -- NEC uPD series from ~ end 1960s

[jefo...@gmail.com]

Dear all, 

I am trying to find the Japanese MOS IC NEC uPD105C. Logic states are 0 and -24V

Two questions: 

(i) does anyone have an old broken calculator containing one or more pieces of this IC ?

(ii) are there any datasheets available on this uPD series of NEC ICs? They most likely were produced around the end of the 1960s. I have been unsuccesful up to now to find any documentation or technical description. 

Any information would be very welcome.

Jef Ongena - Belgium

[Robert J. Simpson]

It's not free but this site lists it as being available:

https://waubmkvm5756xx62fvw7og3eya-jj2cvlaia66be-www-grandpas-shack-com.translate.goog/parts/item.php?itemid=7737

Rob.

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[J Ongena]

Dear Rob ! This is wonderful news, and exactly what I am looking for !

Many thanks. 

Question : 

would you also have a reference for uPD128C ?

and possibly also for Mitsubishi ICs from the series M58xx (e.g.  M5812, M5825 and M58207?

With best regards, and thanks again, 

Jef Ongena Belgium

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[Robert J. Simpson]

There's some info on the Mitsubishi chips here:  http://madrona.ca/e/eec/ics/M5800.html

I haven't been able to find any info on the uPD128C but it appears you might still be able to buy them. If so, you could always try a bit of reverse-engineering.

Is your uPD128C DIL or TO5?

Rob.

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[J Ongena]

Dear Rob, thanks again for the info. All ICs I mentioned are DIL. You mentioned that one can buy still some of them. Do you have a website that offers them, or a person that I could contact ? With my best regards, Jef Ongena

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[Robert J. Simpson]

Jef,

The only company I've used is Little Diode (www.littlediode.com) based in the UK but you'd have to enquire as they don't seem to list them. I found another site: www.sierraic.com which does list them as being in stock but I've no experience of the company. Maybe others could comment?

I couldn't find datasheets for the M2300 series ICs so I bought a couple from Little Diode and then characterised them to figure out how how the flipflops in a Compet-32 work. It was surprising to find the circuit would only work with this specific type of DTL logic and didn't work with e.g. TTL (using LTSpice - not sure how representative those models are).

Rob.

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