Hi piclisters! I have a 'titanic' problem with my program, i made it with several (sub)routines wich i put in bank 2 and bank 3. The Interrupt Service Routine is at 0x04 and main program code comes from ORG 0x25 to 0x180 aprox. Routines can be called from main program and from other routines, and pic (16f84) can't work well, because i don't know how PCLATH must be set after execution of the subroutine. Does anyone solve this problem? Investimento e Investigacisn Industrial, S.L. Av. Galicia 51-53 32300 Barco de Valdeorras (Orense) Spain TLF. : (+34)(9) 88 327370 FAX : (+34)(9) 88 327338 E-MAIL: manuel.castro@mx3.redestb.es