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From: cooper@hpsrad.enet.dec.com (g.d.cooper in the shadowlands)
Newsgroups: comp.arch
Subject: Re: 55 MIPS & 66 MIPS (Galileo)
Message-ID: <603@ryn.esg.dec.com>
Date: 6 Dec 89 02:49:49 GMT
Sender: guest@ryn.esg.dec.com
Organization: DEC Fault Tolerant Systems, Marlboro MA
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In article <40547@lll-winken.LLNL.GOV>, brooks@maddog.llnl.gov (Eugene Brooks) writes...

>In article <1989Dec4.171505.22203@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>>It's also a twenty-year-old design built ten years ago.  Galileo has waited
>>a *long* time to fly, due to an excruciating series of problems with launch
>>vehicles and upper stages.  (In some ways this is a good thing, because a
>>major design defect in Galileo's thrusters was discovered less than a year
>>ago...!)  It is definitely the most complex deep-space mission yet flown,
>>but is not representative of technology that would be used today.

This reminds me of a similar anecdote about the Apollo program, if I
remember correctly.  All of the logic was RTL and they couldn't fit
sufficient gates into the design which is why Armstrong had to
manually pilot the lunar lander.  The original idea was for a computer
controlled landing.

>You mean not representative of technology that would be used in a
>mission designed today, built 10 years from now, and flown 20 years from now.
>Technology changes, but the way such missions are arranged and delayed does
>not...  Please note the lack of a smilie...

And they could have used TTL by the time Apollo was ready to go but it
would have required a total redesign of all of the electronics and n
billion $s.

As a side note, I believe that NASA was the last large scale user of
RTL components.

			 Can you say archaic,

				shades
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