[TUHS] core

Doug McIlroy doug at cs.dartmouth.edu
Thu Jun 21 06:11:24 AEST 2018


>     > Yet late in his life Forrester told me that the Whirlwind-connected
>     > invention he was most proud of was marginal testing

> I'm totally gobsmacked to hear that. Margin testing was
> important, yes, but not even remotely on the same quantum
> level as core.

> In trying to understand why he said that, I can only suppose that he felt that
> core was 'the work of many hands'...and so he only deserved a share of the
> `credit for it.

It is indeed a striking comment. Forrester clearly had grave concerns
about the reliability of such a huge aggregation of electronics. I think
jpl gets to the core of the matter, regardless of national security:

> Whirlwind ... was tube based, and I think there was a tradeoff of speed,
> as determined by power, and tube longevity. Given the purpose, early
> warning of air attack, speed was vital, but so, too, was keeping it alive.
> So a means of finding a "sweet spot" was really a matter of national
> security. I can understand Forrester's pride in that context.

If you extrapolate the rate of replacement of vacuum tubes in a 5-tube
radio to a 5000-tube computer (say nothing of the 50,000-tube machines
for which Whirlwind served as a prototype), computing looks like a
crap shoot. In fact, thanks to the maintenance protocol, Whirlwind
computed reliably--a sine qua non for the nascent industry.




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