Re: [M100] Generating and detecting other tones via the cassette port
> On Nov 22, 2022, at 11:49 AM, Douglas Quagliana wrote: > > Has anyone experimented with generating and detecting tones on the cassette > port other than the standard cassette mark and space frequencies? Douglas, While this isn't a direct answer to your question, for which I apologize, it may be a useful lead to mention that the original heritage TRS-80 Models I / III used the cassette port as audio outputs for music and in some cases speech. I believe the circuit and method of operation was similar -- your approach seems reasonable.
[M100] Generating and detecting other tones via the cassette port
Friends, Has anyone experimented with generating and detecting tones on the cassette port other than the standard cassette mark and space frequencies? The ROM code seems to generate the standard tones just by varying the timing loop iterations, and the detection is a slightly more complicated timing loop while watching/waiting for the signal to go from high to low, so it would *seem* to be the case that changing the values would let you use other audio frequencies in your own assembly code version of the cassette port code. (Basic isn't fast enough.) But...Has anyone actually written any assembly language code to do this? If so, could you send it to me? Douglas
