Xref: utzoo sci.electronics:5639 comp.sys.apple:11334
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!tektronix!reed!kamath
From: kamath@reed.UUCP (Sean Kamath)
Newsgroups: sci.electronics,comp.sys.apple
Subject: Re: Apple II being an oscilloscope
Message-ID: <12141@reed.UUCP>
Date: 23 Mar 89 04:10:43 GMT
References: <1813@uop.edu>
Reply-To: kamath@reed.UUCP (Sean Kamath)
Organization: Reed College, Portland OR
Lines: 40

In article <1813@uop.edu> chaos@uop.edu (Pat Luther) writes:
>
>I have an Apple II (rev. 1) computer (no jokes, I'm serious!)
>and want to make it be an oscilloscope part-time.......

What's so funny?

>Or has anyone done something like this before and has any ideas?

Yes and yes.

>Doesn't have to be fancy, just something to plug into one of the
>expansion slots in back-- I have Apple II proto-boards to do this....
>My main use for this would be doing school-work at home, so I don't
>always have to use the school's equipment, which is not oft accessable.
>
>					Pat Luther

Well, Julian Kilker, good friend (and Peace Corp fool) built such a
system for his thesis.  Basically, he took a 6522 VIA (called a
FlyBoard.  I have a macdraw doc to make one, it's somewhere behind me
on one of my many mac disks. . .  Please don't ask for it till May)
hooked up a ADC820 (8 bit Analog to digital converter) and let fly.  I
also have the source code for the apple.  The only problem (BTW, this
was in real time.) was how to make it go fast enough.  Lores and
double lo-res worked ok (under 15kHz) but he got it up to 22kHz or so
in hires by turning the thing on its ear -- he did it vertically.
That way, for each scroll, he only had to move some 191 bytes
(actually, twice, once to clear, once to set).  Real fast.  In fact,
it digitized at the limit of the //.  Pretty cool.

I'll try my best to give out what I got after I graduate.

Sean Kamath

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