The 84+'s are supposed to be 15MHz. But the careful technique I use in that program shows that they are much faster than that. I know it works because if wabbitemu had the proper clock cycles for adc a, imm8, it would show exactly 15,000,000Hz, which is exactly what it's clocked to. (I forget the math, but if you adjust the number, it comes out right.)
And if you're still not a believer, take a song clocked for your calculator and run it in wabbitemu or vice versa. In wabbitemu it will crawl and on your calculator it will go way too fast.
With RealSound songs they seem to play a bit faster than the original in WabbitEmu, though.
(Old video btw. I no longer have this file)