Thanks, but I don´t know how fast that means.....how many crystal tics or how many micrseconds. The thing is I try look how fast the processor is and determine how much i could pack into the software.....i try to do so...
the pics are all on one small board max 2 inches apart. dream clock speed is 20 Mhz for the master Pic, the small 12F629 just need 4 Mhz.

If the speed is very fast, say 200 microseconds for one complete "Master-slave-Info-cycle" I could use a 36 teeth inductor wheel which gives me fantastic acurracy. Otherwise i have to use the 4-tic per engine cycle wheel and have to interpolate.