Here’s a cool DIY oscilloscope using a PIC12F675 kinda similar to the Atmega Atmel Oscilloscope.
This is a simple PC voltage oscilloscope using only a PIC12F675, a 20MHz oscillator, and a RS232 level shifter. The PIC takes a sample on GP2, immediately sends it to the PC at 115,200 baud using an software asynchronous serial routine, and repeats. It sends a 8-bit value that is read by the Visual Basic