Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site phri.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!whuxl!houxm!ihnp4!qantel!hplabs!pesnta!phri!roy From: roy@phri.UUCP (Roy Smith) Newsgroups: net.columbia,net.space,net.arch Subject: Re: Answer to: What do you call the "blockhouse" now? Message-ID: <372@phri.UUCP> Date: Sat, 3-Aug-85 10:58:01 EDT Article-I.D.: phri.372 Posted: Sat Aug 3 10:58:01 1985 Date-Received: Mon, 5-Aug-85 07:36:36 EDT References: <112@cpsc53a.UUCP> <303@pyramid.UUCP> <775@burl.UUCP> <1590@akgua.UUCP> <1060@ames.UUCP> Organization: Public Health Research Inst. (NY, NY) Lines: 26 Xref: watmath net.columbia:1552 net.space:4416 net.arch:1645 > there is an excellent article in a recent issue of the Annuals of > Computing on NASA space computers. It mentions the use of magnetic tape > drives at a time when everybody else is using disk drives. > --eugene miya If you are interested in the subject of space computers, take a look at CACM, Vol 27, #9 (Sept 1984). To quote from "The Space Shuttle Primary Computer System" by Spector and Gifford in that issue (copyright (C) 1984 by The Association for Computing Machinery, Inc.): AS. Is the memory core? Macina. Yes, it's ferrite core. By today's standards it seems outdated, but it does have certain advantages; for instance, it's inherently nonvolatile when power is removed. I believe core is also much less sensitive to cosmic radiation etc. than semiconductor memory is. Surprisingly enough, the on-board computers are rather non-impressive in terms of computing power; the standard cpu on the shuttle is about a 1/2 MIPS machine. They are designed not to be fast, but to be non-crashable. You cretins arguing SysV vs. 4.2 for better stability will notice that neither system is used on the shuttle. :-) -- Roy Smith System Administrator, Public Health Research Institute 455 First Avenue, New York, NY 10016