I mostly program in C with the benefit of interrupts, but this application calls for small size and price, so I thought I'd ask the piclist. I need to be able to read an incoming square wave, and generate an outgoing square wave based on the first. The frequency is from 10Hz to 1Khz. This is probably very easy for the hardcore micro guys, I guess I've become a bit lazy with my GUIs and high end languages. I've done it in a 16F84, although a bit glitchy (can't trigger well with a scope), but going to the 12C508, I'm a bit lost. Any direction? Craig