> Oscilloscope:
>      Radio Shack sells el cheapo digital scoope. It's about $100. It has a
> small LCD display and it also hooks up to a PC via RS232. Fastest sampling
> rate is 5 ns, but it doesn't have filters before the digitizing process.
> This means you'll see many foldovers if you sample high frequency stuff.
> It's good for quick and dirty stuff. In fact, I think it's a cheapest 5 MHz
> oscilloscope one can buy (digital or analog).

What's the grounding situation if the thing is plugged into a PC?  Does
it have any opto-isolation?  If not, does its output have enough "oomph"
do drive an opto?