Not strictly soundcard, but relevant.
A soundcard oscilloscope is a practical, budget-friendly way to turn your computer into a powerful diagnostic tool. By using your PC's internal or external sound card as an analog-to-digital converter, you can visualize and analyze audio-frequency signals without spending hundreds on dedicated hardware. Top Free Soundcard Oscilloscope Software soundcard scope download gratis
: A professional-grade interface that now supports standard sound cards. It provides advanced features like data logging and serial data decoding. The software is available on the Digilent download page. Not strictly soundcard, but relevant
