; Turn screen on
    ld a,%01000000
;          ||||||`- Zoomed sprites -> 16x16 pixels
;          |||||`-- Doubled sprites -> 2 tiles per sprite, 8x16
;          ||||`--- Mega Drive mode 5 enable
;          |||`---- 30 row/240 line mode
;          ||`----- 28 row/224 line mode
;          |`------ VBlank interrupts
;          `------- Enable display
    out ($bf),a
    ld a,$81
    out ($bf),a