12 Jan
2009
12 Jan
'09
10:13 p.m.
dwight elvey wrote:
Found the web page, and yes, it does seem similar in size and functionality to
the Comdyna GP-6 or 10. I'll follow up with him as you suggest.
In it's 'normal' form the plating has a flat white-grey appearance, no blue
or
yellow tinge as one gets with other plates. To my observation it was used
roughly from the late-30's/40s to the 60s/early-70's and then (thankfully)
seems to have fallen out of favour.
From: hilpert at cs.ubc.ca
There are a total of 10 amps. 4 can be configured as integrators or summers, 4
are just summers. 2 have associated circuitry to make them into multipliers
or dividers, or can be used as just summers.
Hi
It does sound like what was used as the basis for the Comdyna 10.
You might email the fellow at Comdyna and ask if he recognizes this
machine. It's
currently in a million pieces across 3 workbenches, almost ready for
reassembly. (Most of the nuts and screws and a few other metal parts had grown
that white powder that develops under certain conditions on some metal
surfaces. I've seen it on other equipment, I presume it's an oxide of the metal
plating, although it also has the appearance of a mildew or fungus. I'm not sure
what element the plating is. Fortunately, it's only a 'mechanical' issue, it
isn't
affecting the circuitry or contacts.)
Most likely zinc, lead or aluminum oxides. This is common for items store
where they might have condensing moisture. I've played some with them. A fun example is the
bouncing ball example
from the EC-1 by heath kit. It will give you an idea of how one models
a physical system into the computer.
Look at the configuration. There is a way to reduce the number of
op-amps needed by one ( I forget now ). It saves two free amps that
can be used to create a sine/cosine oscillator for the ball instead of
the 60 Hz one in the example. For use with a plotter, you don't want
the ball anyway, it is just fun on an oscilloscope but not needed
otherwise. A dot bounces just as nicely.
.. have to see if one can still get the manual for the EC-1, re discussion of a
couple of weeks ago about access to Heath manuals being removed from the web.