Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!mit-eddie!ll-xn!ames!elroy!jpl-devvax!beowulf!david
From: david@beowulf.JPL.NASA.GOV (David Smyth)
Newsgroups: sci.space.shuttle
Subject: Re: Shuttle computer reprogramming
Message-ID: <3011@jpl-devvax.JPL.NASA.GOV>
Date: 7 Oct 88 19:06:31 GMT
References: <6689@nsc.nsc.com> <6980@ihlpl.ATT.COM> <1938@kalliope.rice.edu> <2993@jpl-devvax.JPL.NASA.GOV> <1972@kalliope.rice.edu>
Sender: news@jpl-devvax.JPL.NASA.GOV
Reply-To: david@beowulf.JPL.NASA.GOV (David Smyth)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
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-phil@Rice.edu (William LeFebvre) writes:
->leem@jplpro.JPL.NASA.GOV (Lee Mellinger) writes:
->>The computers are 4Pi/AP-101's which are esentially ruggedized IBM
->>360's in a small box.  That is the four prime computers, the fifth is
->>a Rockwell/Autonetics machine.
->
->Wrong!  All FIVE general purpose computers (GPCs) are the same hardware.
->They all sit on the same synchronized bus.  Hardware-wise, they are
->totally identical.  It's the SOFTWARE that's different.  Four run the
->standard flight software while the fifth runs the backup flight software
->(the latter being written by Rockwell).  The backup software can be loaded
->into any of the 5 GPCs, just as the main flight software can be loaded
->into any of them. ...

The primary software was written by IBM, the backup by Intermetrics
under contract to Rockwell.  Rockwell only supplied the lab for debugging,
no software or software design whatsoever.

I was there...