Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!csinc!rpeglar
From: rpeglar@csinc.UUCP (Rob Peglar x615)
Newsgroups: comp.arch
Subject: Re: ETA10 (was Re: Surges)
Message-ID: <153@csinc.UUCP>
Date: 22 Nov 89 16:00:39 GMT
References: <3217@convex.UUCP> <5290@internal.Apple.COM> <7043@pt.cs.cmu.edu> <3266@convex.UUCP>
Organization: Control Systems, Inc., St. Paul MN
Lines: 25

In article <3266@convex.UUCP>, schumach@convex.com (Richard A. Schumacher) writes:
> 
> The LN2 cooled the chips by boiling, not by conducting away the heat.
> The resulting vapor was then recondensed and re-used (at all user sites) or 
> just thrown away (at the manufacturing facility). It turned out that at
> about $0.25/liter it was cheaper just to throw it away, rather than pay
> electricity costs, amortized capital cost, etc., for the closed system!
> (Most customers realized this and wanted an open system, but ETA dithered 
> over it for two years or so...)

True enough.  There were sites in the US that were considering open-loop
operation.  In the US, LN2 is quite cheap.  However, in Europe and
Japan, not the case, so closed-loop was a necessity.

As for dithering, ETA dithered over a lot of things, the least of which
was open-loop cryogenics.

Rob


-- 
Rob Peglar	Control Systems, Inc.	2675 Patton Rd., St. Paul MN 55113
...uunet!csinc!rpeglar		612-631-7800

The posting above does not necessarily represent the policies of my employer.