;; This example shows a suggested startup for a cartridge ;; cartridge page 0 exists at &0000-&3fff ;; execution starts at &0000 ;; org &0000 start: di ;; disable interrupts im 1 ;; set interrupt mode 1 ld bc,&f782 ;; setup initial PPI port directions out (c),c ld bc,&f400 ;; set initial PPI port A (AY) out (c),c ld bc,&f600 ;; set initial PPI port C (AY direction) out (c),c ld bc,&7fc0 ;; set initial RAM configuration out (c),c ;; unlock ASIC so we can access ASIC registers ld b,&bc ld hl,sequence ld e,17 seq: ld a,(hl) out (c),a inc hl dec e jr nz,seq ;; set initial CRTC settings (screen dimensions etc) ld hl,end_crtc_data ld bc,&bc0f crtc_loop: out (c),c dec hl ld a,(hl) inc b out (c),a dec b dec c jp p,crtc_loop ld hl,&c9fb ld (&0038),hl ei ;; enable asic ram (will be visible in range &4000-&7fff) ld bc,&7fb8 out (c),c ;; your code here loop: jr loop ;; your crtc setup values here; these are examples crtc_data: defb &3f, &28, &2e, &8e, &26, &00, &19, &1e, &00, &07, &00,&00,&30,&00,&c0,&00 end_crtc_data: ;; sequence to unlock asic sequence: defb &ff,&00,&ff,&77,&b3,&51,&a8,&d4,&62,&39,&9c,&46,&2b,&15,&8a,&cd,&ee end start