On Sun, 6 Aug 2000, Marko Mäkelä wrote: > I've looked at the combined waveforms by sampling the OSC3 register every > 16 or 32 cycles (I don't remember; anyway, I wrote the sampling loop so > that crossing 256-byte boundaries made no difference in the sampling > frequency). At double waveform frequency, the output changes at double > speed; there are no irregularities. The cycles of the waveforms were 512 > bytes, unless I remember wrong. This information is for the 6581; I > haven't tested the new SID. I've only ever had silence out of 6581s for the combined waveforms. Perhaps they are quiet. > So, there's no need to have a REU to measure the waveforms. Yeah, but it's a helluva lot easier ;) By the way, I have also coded cycle-exact timing routines for sound applications; I wrote a subroutine to generate NES-style stepped triangular waveforms on the volume register and it was as tight as possible as well as accurrate on 256-byte boundaries. I had to specify its location within a page so as to generate a 1 cycle penalty on certain branch instructions. Do you still have your program? Richard -- Richard Atkinson Software Engineer Tenison Technology EDA Ltd http://www.tenisontech.com/ - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail email@example.com.
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