On Fri, 10 Oct 2003 14:19:36 -0700, "Alex Daniloff"
The problems with all these elder CPUs and chips are.
1. Most of them are out of production for decades, thus no replacements available. 2. Reliability of a chip is decreasing exponentially with the time, due to electromigration, diffusion and other internal processes. 3. Electronic chips are constantly aging, no matter if they used on unused.
I think you'll find that contemporary versions of the 8086 and Z80 chips are still in production and use, as are a number of other chip families from the 1970's. No one is putting 30-year old chips in the Shuttle. Besides, using something like a Pentium-4 or an Athlon XP in many places onboard the Shuttle would be overkill and a gross waste of money.