A PICmicro w/ PWM may do the trick -DS Tuesday, November 09, 1999, 4:19:16 PM, you wrote: RFI> Does anyone know an IC that perform an "byte controlled oscillator"? RFI> Such IC must have to work like this: -I send an string and it start to RFI> generate an square wave with frequency proportional to the byte (or RFI> word) value. RFI> See you, RFI> Beto. Hi, my name is Any Key. Please don't hit me!