30 Sep
2002
30 Sep
'02
9:35 p.m.
From: "Ben Franchuk"
<bfranchuk(a)jetnet.ab.ca>
Ross Archer wrote:
It goes beyond that... there is a Silicon-On-Saphire version which is
considerably more rad-hard than a pure silicon process. In fact even more
recent space probes like Galileo (launched 1989) used 1802s.
The 1802 was used in quite a number of Amateur
radio ("ham")
satellites.
It was one of the first relatively "rad-hard" micros from
what I remember
reading, due in large part to its CMOS construction. I
guess those days
there were a few PMOS CPUs (8008, 8080) and a few NMOS CPUs
(Z80, 6502,
9900JL), and exactly one CMOS CPU -- the CDP1802. So it was
1802 or bust. :)
The other CMOS chip at the time was the PDP-8 on a chip.
The 1802 was I think was a special CMOS version that was
latch up and rad-hardened. Several CPU's are rad-hard but
the 1802 was the first cheap one.