toback2 ([log in to unmask]) wrote:
: Gavin Scott writes:

: >There was a quite interesting article many years ago in the Journal of the
: >ACM that described the 5 main computers that controlled Space Shuttle
: >flights at that time (and knowing NASA's conservatism, probably still do).

: Yes, they still do. Another description of the computers, and of the
: testing procedures, is in Richard Feynman's book, _Surely You're Joking,
: Mr. Feynman_, which includes Feynman's own report on the Challenger
: accident as an appendix. (He didn't sign on to the main report.)

As I recall, those computers still use magnetic core memory.  That
allows the astronauts to power off some of the computers during
certain phases of flight without losing the contents of memory.

Walter