## Keyboard shortcuts

Press `←` or `→` to navigate between chapters

Press `S` or `/` to search in the book

Press `?` to show this help

Press `Esc` to hide this help

# Gameboy

Assembler code

    ROM:0ABF                 db  23h ; #
    ROM:0AC0                 db  10h
    ROM:0AC1                 db 0EEh ; î
    ROM:0AC2                 db 0C9h ; É
    ROM:0AC3 ; ---------------------------------------------------------------------------
    ROM:0AC3                 ld      a, (4DA4h)
    ROM:0AC6                 and     a
    ROM:0AC7                 ret     nz
    ROM:0AC8                 ld      ix, 4C00h
    ROM:0ACC                 ld      iy, 4DC8h
    ROM:0AD0                 ld      de, 100h
    ROM:0AD3                 cp      (iy+0)
    ROM:0AD6                 jp      nz, loc_BD2
    ROM:0AD9                 ld      (iy+0), 0Eh
    ROM:0ADD                 ld      a, (4DA6h)
    ROM:0AE0                 and     a
    ROM:0AE1                 jr      z, loc_AFE
    ROM:0AE3                 ld      hl, (4DCBh)
    ROM:0AE6                 and     a
    ROM:0AE7                 sbc     hl, de
    ROM:0AE9                 jr      nc, loc_AFE
    ROM:0AEB                 ld      hl, 4EACh
    ROM:0AEE                 set     7, (hl)
    ROM:0AF0                 ld      a, 9
    ROM:0AF2                 cp      (ix+0Bh)
    ROM:0AF5                 jr      nz, loc_AFB
    ROM:0AF7                 res     7, (hl)
    ROM:0AF9                 ld      a, 9
    ROM:0AFB
    ROM:0AFB loc_AFB:                                ; CODE XREF: ROM:0AF5↑j
    ROM:0AFB                 ld      (4C0Bh), a
    ROM:0AFE
    ROM:0AFE loc_AFE:                                ; CODE XREF: ROM:0AE1↑j
    ROM:0AFE                                         ; ROM:0AE9↑j
    ROM:0AFE                 ld      a, (4DA7h)