Yes thank you. I understand. I thought that ldir increaments bc (Poor explination in z80iss). However, I don't know how the part after the first ldir in this piece of code from falldown works: Scroll_U: LD HL, $8e29+12 LD DE, $8e29 LD BC, 756 LDIR LD H, D ; Starting here LD L, E INC E LD (HL), B LD C, 11 LDIR RET From: Chris (Man in the Moon) man_in_the_moon@usa.net