[Oscar] had an old external modem sitting around and, with some wise hardware choices, he came up with a simple circuit to use it. First up is the PIC 16F628A chosen because it doesn’t require ...

It’s actually a 14.4 Kbps modem, which brings back memories of the ... [Alex] altered the circuit board to map out an ICSP port for the PIC 16F690 that controls the system.