You're going to have to explain a bit more about how this would measure its frequency. (I can't control its phase, if that's what you were thinking.)tepples wrote:Could you make a tone by bit banging the log volume of an ultrasonic (period 0 or 1) wave and then compare the volume of that tone to other volumes you can coax out of the chip?rainwarrior wrote:I don't think I'd tested this before, but using a value of 0 for the envelope's period does not halt it. It will instead behave exactly as if its period value was 1. (I have been told that the square wave tones do this as well, but the resulting frequency is above audible and I haven't verified with a scope.)
I'm pretty sure that I've verified in the past that it doesn't halt, and that it makes output (when trying to see if it would reset phase). The unverified part is just the frequency.
The only reasonable idea I have for this frequency is that it's a duplicate of period 1 (56 kHz), which would be consistent with the envelope and noise and some other emulator implementations I've seen. 0 as a value doesn't work as a division, obviously. I don't know what's left to consider otherwise? It's above audible. It's not zero. So... it's either equivalent to 1 or 2, or it's something else out of left field.
If I could generate some other frequency close to it but slightly different maybe I could get it to heterodyne, but everything is dealing with divisions of the same clock... maybe $4011 has a chance there?
...or I could just measure it with a scope, probably.
Either way, if it isn't 1 the difference is probably going to be too trivial for most emulators. One inaudible result is probably as good as the next.