ScopeOnPC is a free software that uses the PC parallel port and an ADC (Analog To Digital converter) circuit to turn your PC into a full featured ocliloscope. Sampling: 100K Samples per second (DOS version) -100KHz Sampling: 40K Samples per second (Windows version) – 40KHz -5 V To +5V Input Range -50V To +50V Olerload Protection 8 Bit Resolution Scope Timebases:100uS/Div To 100mS/Div Scope Volts/Div: 100mV/Div To 5V/Div Works with ANY parallel port.
Version 2 now has DC volt meter.
The ADC Converter is an analog to digital converter circuit based on
ADC0820 or the compatible TLC0820.
You can build it on wire wrap/hand wire board, Proto Board or on a PCB.
Hardware circuit in official site
Download ScopeOnPC 2.0 Windows
Download ScopeOnPC 1.5 DOS