The Microchip parts that were around in 1990 didn't run that fast, Charles. There was a company, Scenix, now Ubicom, that cropped up about that time that made a version of the really early PIC's (16C5x) that did run at high speed, and, in fact, it didn't use that divide-by 4 prescaler that the Microchip parts include. They operate at up to 100 MHz, but, their mfg doesn't make 'em any longer, as they were too much trouble to program.

I never learned to like 'em, but, what they hey, I use whatever they pay me to use.

RE