* James Knott
Philip Amadeo Saeli wrote:
* John Grant
[2004.10.15 06:42]: Oh, and just to stay on-topic(?).. anyone ever heard of 1108s, 1802s? Cosmac VIP ring a bell?
[peeking head out of the woodwork ...]
Yup! While at JPL around 1984, messed about some with the Galileo flight software which ran on a redundant multi-cpu 1802 based system. I was on the Magellan (then was Venus Radar Mapper) project which, being a low budget project, was using as much of the Galileo project development as possible.
As I recall, one reason for going with the 1802, was that being CMOS, it was less sensitive to radiation, than the other NMOS CPUs.
Exactly right. I believe this was the main reason, though power consumption was also very important, given that (for Galileo, at least) all power was generated from the heat of nuclear decay (Magellan could use solar power due to Venus' close position to the sun). It wasn't until some time later that processors with more modern architectures (and better performance) became available in rad-hard (generally CMOS) versions. That occurred, however, after my stay at JPL had ended. Phil -- Philip Amadeo Saeli SuSE Linux 8.2 psaeli@zorodyne.com