[vcf-midatlantic] EAI TR20 analog computer exhibit
hjohnson at retrotechnology.info
Fri Nov 18 10:53:08 EST 2016
SVCatITC [Bill Inderrieden] posted:
>> I need analog math problems to be submitted, so that when the
>> TR20 is restored, we'll have simulations to run on the computer.
>> I'll make a list of what computational modules we have so you
>> know what to work with, i.e. integrators, DFG's, summers, etc.
>> The plan is to have an XY recorder and XY scope for results output.
Bill and all: I've taken the liberty to post a reply under a proper
subject line that's relevant to the thread. Not "digest question blah
blah" which is irrelevant and will be impractical to search back for in
the future. I really encourage people who post, to use relevant subject
lines, but this is up to the Moderator to enforce, (except when he
Bill, I worked with EIA analog computers long ago, and I'm an old
electrical engineer. So it's good to see this EIA TR20 will be restored
and demonstrated. But very few people in the VCFed list, have any
experience with analog computing or with differential equations. Fewer
visitors will know this stuff.
The classic demo of these sorts of systems, is some kind of "bouncing
ball" display. Everyone has seen a ball bounce, so it's familiar. There
ought to be enough integrators to make a damped oscillator. Since you
want a chart recorder output, the frequencies will be sub-audio.
But you might allow for a speed-up at audio rates, so an oscilloscope
and speaker can demonstrate operation, without requiring the chart
recorder and using up paper and ink - all points of failure, weeks and
If it were my choice, I'd go "audio" so it's easier for the docents to
demonstrate the unit and avoid problems with chart recorders.
That's my considerations. Something simple, familiar, and convenient to
demonstrate when you aren't there. The amazing thing will be that it
works, and has been preserved. We can run real programs, another day.
Herbert R. Johnson, New Jersey USA
http://www.retrotechnology.com OR .net
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