cncmachineguy, TIMER1 interrupt with a carefully chosen pre-set sounds good to me. I am not succeeding in figuring out how to do it. Page 32 in the 887 spec talks about PIE1. Page 70 talks about T1CON. I do not know where to look for an example.

Is there a collection of PBP and ASM code samples? If so, where?

Ken