On Sat, Jul 28, 2018 at 10:14 AM, Douglas Quagliana <[email protected]> wrote:
> I'd like to know if there's a way to get the cassette port to recognize > AX.25 Bell 202 packet radio tones (1200 Hertz and 2200 Hertz at 1200 > baud). I think the cassette port audio input pin get routed to the CPU but > it only knows "HI" and "LO" so I don't think it can detect sinewave > waveforms, but I would really like to be proven wrong on this. If it > worked, it would let you run packet radio right off the cassette port and > use the cassette motor as a push-to-talk. > > The cassette protocol is based on measuring time between zero crossings. My understanding agrees with yours that unlike, say, the Coco, the cassette hardware cannot be used for general A/D conversion. -- John.
