>> Is there even one mid-range device that dosen't support the TRIS >> instruction on ports A,B and C? > Officially many of them don't, including the 16F872. Same for 873,4,6,7 (TRIS is not mentioned in the instruction set). But it does still work in all chips I use.... Wouter van Ooijen -- Van Ooijen Technische Informatica: http://www.voti.nl Jal compiler, Wisp programmer, WLoader bootloader, PICs kopen -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.