Oldest operational computer was Re: cctalk Digest, Vol 54, Issue

Richard legalize at xmission.com
Thu Feb 14 14:02:21 CST 2008


In article <1203009683.32199.0.camel at elric>,
    Gordon JC Pearce <gordonjcp at gjcp.net>  writes:

> > Tubes back then barely worked. When they did work, they barely
> > amplified. And you were lucky to get 50 hours out of them. A try
> > getting two that were vaguely similar electrically. And then try to
> > find someone that actually knew how the things worked.
> 
> Why do you suppose they barely worked?  Because no-one could make them,
> or because no-one had figured out what to make them out of?

The book "From Whirlwind to MITRE: The R&D Story of The SAGE Air Defense
Computer" has quite a bit of coverage of the methods used on Whirlwind
(and SAGE) to get repeatable quality components.  Even in the late
1940s and early 1950s, the variance and reliability of components was
not built in by the manufacturers.  As a user of the devices, the MIT
team developed methods for testing and characterizing components and
rejecting the components most likely to fail early.  This knowledge
fed back to the manufacturers to the point where the manufacturers
started doing their own testing and QA of their components.  According
to the book, this was the first systematic attempt at characterizing
these sorts of components (tubes) in any meaningful way.
-- 
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