I stand corrected re the Shuttle computers. I just looked up the info. I must be misremembering the Apple II reference. Perhaps it was that the Apple II is more powerful than the Shuttle computers? I dunno. It was a long time ago I heard it.

But in a nutshell, the Shuttle originally used five IBM AP-101 computers made from discrete TTL integrated circuits and 64K of core memory and could do about 400K instructions per second. They were upgraded in the 90's to the 3 times faster AP-101S with 1 meg of semiconductor based memory. Further upgrades were to the avionics from analog gauges to a 'glass cockpit'.

The computers are also used by the Air Force in planes like the B-52 and F-15. The Shuttle computers are programmed in HAL/S whereas the Air Force uses JOVIAL.

Brian