On Fri, 31 Oct 2014, N_Cook wrote:

Did they ever exist? Why would some company make IC eqivalents for ICs
that were used in 30 year old domestic equipment? I could understand,
for keeping ancient industrial equipment going. Or is it just another
Google-ad income generator? eg NEC uPC1167 FM radio IC of circa 1980,
apparently equivalent to NTE1488, complete with apparent datadsheet with
OCR/translation errors from Japanese original data sheet

There were lots of replacement lines, RCA SK, Motorola HEP, Radio Shack
had a small selection, I recall GE did for a while. It was an attempt at
providing a universal line, when otherwise getting the part meant dealing
with multiple sources. Some were better than others. Radio Shack wsa
pretty limited. HEP started out small, and the ICs were mostly Motorola
(and they at least aimed it at the "Hobbyist, Experimenter, Professional",
so for the first two, "something close" was good enough, and it was more
important to be able to get reasonably current ICs in West Podunk, ND than
to get it cheap only if you mail ordered. HEP got better with time, but
like some of them, the replacements were generally work alikes rather than
exact, so the substitution guide would often cross to a similar sort of
IC rather than an exact match.

I had various guides, they were useful since it was easier looking up
transistor specs and not hving to go through differnet books from
different manufacturers. But since the replacement parts were so
expensive compared to the original, I couldn't afford the replacement line
parts.

ECG and then NTE came later, and offered a higher level of replacement.
They were less about workalikes than exact replacements. Each were a much
mroe extensive line, which meant a store that stocked them had to carry
more items, but at least they all came from the same source. Or I suppose
if they didnt' carry it, they could get the item from the distributor
fast, and still avoid having to deal with multiple distributors.If you
looked up a part in the ECG or NTE guide (that eventually became one and
the same), you were getting either the part, or very close to it. Earlier
replacement lines would expect you to live with a generally the same type
of transistor (though at least those were prime components if you were
buying from Motorola), so a lot of devices would cross to the same
replacement part. ECG and NTE seemed to try to be a lot closer match,
hence the much larger replacement line.

Michael