I'd like to setup an ISR such that something happens every 100 cycles, but only for the first 1000 cycles. I'm sure this is simple but I'm not seeing it. Pseudo code:

ISR(TIMER0_COMPA_vect) { startupFlashCount++; if(startupFlashCount =< 1000) { if(startupFlashCount [IS A MULTIPLE OF 100]) { DO_SOMETHING; } } }

Its that "IS A MULTIPLE OF 100" that I'm not getting right. Feel free to suggest a better method. Thanks.[/code]