Saw this: LC0BD bita #$01 * CHECK TO SEE IF ACCD IS ON AN EVEN beq LC0C2 * 512 BYTE (ONE GRAPHIC PAGE) BOUNDARY - ADD inca * 256 (INCA) TO IT IF NOT LC0C2 tfr A,B COPY ACCA TO ACCB Why not just: inca anda #$FE tfr A,B Juan