I used to have a software where you could virtually create an electronic circuit and test it. I am drawing a blank and cannot think of the name. Anyone remember / use the software ?? What was it called ?? Is there something similar ??

I installed a software that let me use the PC as an oscilloscope , but
it does not mention how to connect the circuits to be tested with the computer an through which port.Does anyone lead me?
I mean how can I connect that cable to
the circuit ?