It works, sort of (20mhz crystal 16F876A).

If any channel duration has same value, these channels won't play.
Also, playback duration is different each time, it might play 4 or 5 times same duration, then 2 times shorter duration, then again normal.
It works properly only when value of output timings is first is the shortest, 2nd medium and 3rd - longest. If in reverse, it will only play last, short one.