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From: ISW@cup.portal.com (Isaac S Wingfield)
Newsgroups: sci.electronics
Subject: Re: Stepper Motor & old technology
Message-ID: <19964@cup.portal.com>
Date: 28 Jun 89 18:24:59 GMT
References: <7137@cbnews.ATT.COM> <1137@cbnewsc.ATT.COM>  <19588@cup.portal.com> <736@xroads.UUCP> <3262@kitty.UUCP>
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(Larry Lippman mentions ball-disk integrators)

Yeah, I used to have one of those; I was gonna make a computer
for sports car time-speed-distance rallys (way before TTL)

A 4 inch disk unit can do integrations accurate to about one
part in 10,000, and that's with direct friction drive. The
optically coupled units Vannevar Bush used were even better.

I agree, Larry, knowing the technologies of the past can be a
real help in solving peculiar problems.

Isaac     isw@cup.portal.com