Hans,
That is just parts of my code, the interrupt verctor table is set correctly and STP is the Step counter, but I tought that the clr instruction would clear a whole byte, that not true?
the Init subroutine has its ret correctly too.

if u would like to see all the code i could post here... but it have 7 segment display handling and other few thing that dont have to do with the DMX problem.

thanks anyway. Gabriel