4 Nov
2011
4 Nov
'11
7:07 p.m.
Chuck Guzis wrote:
National also had a parallel series of CMOS chips,
with 4000
equivalents, the MM56xx series.
Wow, never heard of those. They had MM74Cxxx parts, which were
functionally equivalent to the other 74xx parts but with CD4000
equivalent electrical performance and timing.
Did anyone actually use a 4581 ALU in anything?
I've always
wondered if anyone built up a CPU from 4000 CMOS...
RCA had a bit-slice part in one of their 1970s COSMOS databooks, with an
app note in the back, but I've never been able to find that particular
COSMOS databook again, so if it went into production at all it must not
have lasted very long. My recollection is that it was not as fancy as
the Am2901.
RCA did make some CMOS parts intended for building a DSP processor. I
think I've got a slim "user manual" for them somewhere. Intended for
military applications.