Hi,

I'm trying to write a small interrupt driven player for YM3812 VGM-Files for MSDOS.

The format of the VGM File for OPL seems to be quite straight forward:
The VGM Command 0x5A is followed by the OPL register and the value
and VGM Command 0x61 is a delay command followed by a 16Bit-word (specification tells 65535 is a about 1,49 seconds)

So far, so easy and the song "plays" ..
But I don't get the right timings, so when playing the song it's too fast, too slow or jitters ..

What are the correct settings for the PIT? what for the delay? Atm PIT is set to 1000Hz what is obviously not correct, but I have no idea how to set/play it right.
And what does "input clock rate" (offset 0x50), which is "3579545", mean?

That sound stuff is driving me nuts 😀

Thx