I'm not really worried about code space, the EEPROM size is more of alimitation, because that determines the maximum size of the sparkadvance table, if we want to be able to update the table through theUART without reprogramming the chip. Alternatively, a bootloader couldbe used, but the smaller and older PICs can't support bootloaderfunctionality.

If we're going to use a different board anyway (in the future), wecould also use a different controller (not even necessarily a PIC, itcould also be an AVR, or something completely different), and use theon-board peripherals.

I think I'll try to use the input capture function, but also provide a(less accurate) polling-based alternative, and use a timer interruptfor the output timing. I could correct for the interrupt latency when setting up the timer.

Does anyone know if there is a PIC that is pin compatible (for the pins that matter; mostly, the power supply) with the 16F628? If so, and if the alternative has the features we want, the existing boards could still be used, with a replacement controller.