Surfer writes:

It would be helpful for some of my electronic projects to
have a simple oscilloscope,

An old, old issue of Probe magazine (perhaps 1990 or so) had
plans for an o-scope circuit that fed the parallel port,
including the matching software. It could be easily modified to
do what you need. Perhaps a library would have these magazines
on microfilm.

Some links to PC scope projects can be found at
http://www.epanorama.net/links/measu...ml#pcmeasuring
and http://www.epanorama.net/links/measu...l#oscilloscope

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/