17 ?

I helped a guy build a metronome with an 8052. Its pretty simple to do, we had an LCD and a couple of up/dn button to select beats.

We experimented with a "beat meter" where you pressed a button on the beat and the rate was displayed on the LCD.

We also tried a tuner too, that gave out accurate musical notes (heavily filtered)

All of this should fit in a Philips CPU now, though we managed with the DS2250.

Steve