On Sun, 10 Apr 2005 03:07:22 -0700, Aaron Lehmann wrote:
Bipolar logic became obsolete long ago. Modern CPUs are based on CMOS.
In fact, I've never seen a bipolar microprocessor.
They do exist. Well, sort of - not much _micro_ about them :-) - a PDP11-04
main processor was entirely bipolar logic - the board is about 30x20cm - I've
got a couple somewhere.
IBM introduced CMOS-processors in their ES9000 range around 1991 - prior
to that they were all bipolar ECL and watercooled.
Many (most?) minicomputers in the early 1970s were entirely TTL bipolar... For example, the early 1970's Data General Nova 1200 was based on 74181 ALUs and 74xx discrete logic decoders, sequencers, etc. The core of the CPU was an entire 12x15"(?) logic board... Before that, early/mid 60's IBM stuff like early model System/360, and the IBM 1130 were built with hybrid discrete RTL logic, they switched to TTL later in the 60s.
specific to MICROprocessors, early Intel stuff like the i4004 was PMOS, the very popular i8080 was, I believe, updated from PMOS to NMOS with the updated 8080A version in 1976 or so... I don't think Intel came out with CMOS until the 'CHMOS' stuff like the i80C86 CPU (most 8088/8086 CPUs were still NMOS or HMOS, but there was a CMOS version, the 80C88,etc..). First natively CMOS mainstream Intel CPU was the i80386DX circa 1985. First mainstream successful CMOS microprocessor I'm aware of was the RCA "COSMAC" 1801(?), circa 1975.
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