I need a good, low cost computer Oscilloscope that doesn’t use the paralel port. Does anyone know where I can get free(free domain) plans and software for this?
Google computer oscilloscope
I am not sure why you are interested in this but it may be that it is not such a good idea after all. You can get traditional scopes pretty cheap. OTOH the computer should allow ex post facto processing. One site suggests using the audio input but that would limit you to lower frequencies.