Ok, ill have a look around for it. Im using a 20MHz oscillator already. The baud rate for the serial data is 115200. I would have thought that uses more processing power but i did have this working earlier. The problem seems to be with the code between the serial data arriving and the LEDs being turned on. Im still cutting as much out as possible but theres a limit to how small a program can be before it doesnt do everything you want. Ill probs strip my program back to basics when i test out that software PWM thing then build it up a few lines at a time.