The amount of audio samples generated by the PC Speaker appears to be off by a small amount, so after a while the PIT's channel 2 is active an excessive amount of data accumulates into the audio buffer and the audio sounds desynchronized.
The speed and amount at which this desynchronization happen depend on the running program and seems to be faster the more complex the music is.
Still unclear if the problem is the audio rendering routine or the PIT emulation.
The amount of audio samples generated by the PC Speaker appears to be off by a small amount, so after a while the PIT's channel 2 is active an excessive amount of data accumulates into the audio buffer and the audio sounds desynchronized. The speed and amount at which this desynchronization happen depend on the running program and seems to be faster the more complex the music is. Still unclear if the problem is the audio rendering routine or the PIT emulation.