2 Jul
2006
2 Jul
'06
1:54 p.m.
Philip Pemberton <philpem at dsl.pipex.com> wrote:
I'd have thought the AC coupling hardware would
have caused problems with
that, and you'll have a maximum frequency limit of about 20kHz due to the
low-pass filters on most sound cards.
And I doubt the parallel port would be fast enough.
Non-existent problems.
I've been doing this since the 70's and AC-coupled scopes are just fine
as long as you don't do any horribly baselined stuff. And with regards
to rate and CPU speed, I never had any problem using CPU's that were
realistically a tenth of a MIP or slower :-).
If it's just a half-dozen letters then there's dozens of ways to
implement it (some of them COMPLETELY ANALOG.)
My favorite thing to put on a X-Y scope is in fact the output of
an analog computer. See Paul Horowitz's Lorenz equation integrator
for a wonderfully chaotic example:
http://frank.harvard.edu/~paulh/misc/lorenz.html
I built this, added some knobs to twiddle the parameters,
and hooked it up to a 10" X-Y display and am very happy :-).
Tim.