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From: phil@eecs.nwu.edu (William LeFebvre)
Newsgroups: sci.space.shuttle
Subject: Re: New Shuttle Computers
Message-ID: <1991Mar4.202334.22118@casbah.acns.nwu.edu>
Date: 4 Mar 91 20:23:34 GMT
References: <2352@ksr.com>
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Reply-To: phil@eecs.nwu.edu (William LeFebvre)
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In article <2352@ksr.com>, jfw@ksr.com (John F. Woods) writes:
|> The Electronic Engineering Times for 25 February 1991 has an article about
|> the new shuttle computers which are scheduled to fly on Discovery "next week."
|> The new AP101S computers use static-RAM memory and Schottky logic, replacing
|> the old core-memory AP101B computers.

Does the article say if the RAM is battery-backed or otherwise anything
in place to make the memory non-volatile?  One standard procedure is
"freeze-drying" a GPC (general purpose computer), which relies on the
memory being non-volatile.  I'm curious if they are going to scrap that
procedure or not.  Freeze-drying consists of loading the re-entry software
into a GPC and turning the GPC off.  That way if the tape drives that
contain the software both break, at least they have one computer to
get them home again.

Thanks for the summary!  My wife will be most interested in it.

		William LeFebvre
		Computing Facilities Manager and Analyst
		Department of Electrical Engineering and Computer Science
		Northwestern University
		<phil@eecs.nwu.edu>