[sci.electronics] Apple II being an oscilloscope

chaos@uop.edu (Pat Luther) (03/14/89)

I have an Apple II (rev. 1) computer (no jokes, I'm serious!)
and want to make it be an oscilloscope part-time.......

Does anyone out there know how to accomplish this?
Anyone know of any source where design was published on how to make one?
Or has anyone done something like this before and has any ideas?

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.

I've seen it done, many years ago, but that was before I even got my
own computer, so I have no idea how to reach the guy who had it....

Anyway, if anyone has seen designs for this sort of thing somewhere,
or has any suggestions on where to look for them, or knows how to
do it, i'd be grateful for any reply.

					Thanks in Advance,
					Pat Luther
--
Patrick T. Luther  
chaos@uop.edu   OR:  uop!chaos@ucdavis.edu
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"If two people agree on everything, one of them is not necessary."

kamath@reed.UUCP (Sean Kamath) (03/23/89)

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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