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