;; &0000-&0188 &188 bytes (392 bytes) ;; &0800-&0988 &188 bytes (392 bytes) ;; &1000-&1188 &188 bytes (392 bytes) ;; &1800-&1988 &188 bytes (392 bytes) ;; &2000-&2188 &188 bytes (392 bytes) ;; &2800-&2988 &188 bytes (392 bytes) ;; &3000-&3188 &188 bytes (392 bytes) ;; &3800-&3988 &188 bytes (392 bytes) ;; &4508-&4800 &2f8 (760 bytes) ;; &4d08-&5000 &2f8 (760 bytes) ;; &5508-&5800 &2f8 (760 bytes) ;; &5d08-&6000 &2f8 (760 bytes) ;; &6508-&6800 &2f8 (760 bytes) ;; &6d08-&7000 &2f8 (760 bytes) ;; &7508-&7800 &2f8 (760 bytes) ;; &7d08-&8188 &480 (1152 bytes) ;; &8800-&8988 &188 bytes (392 bytes) ;; &9000-&9188 &188 bytes (392 bytes) ;; &9800-&9988 &188 bytes (392 bytes) ;; &a000-&a188 &188 bytes (392 bytes) ;; &a800-&a988 &188 bytes (392 bytes) ;; &b000-&b188 &188 bytes (392 bytes) ;; &b800-&b988 &188 bytes (392 bytes) ;; &c508-&c800 &2f8 (760 bytes) ;; &cd08-&d000 &2f8 (760 bytes) ;; &d508-&d800 &2f8 (760 bytes) ;; &dd08-&e000 &2f8 (760 bytes) ;; &e508-&e800 &2f8 (760 bytes) ;; &ed08-&f000 &2f8 (760 bytes) ;; &f508-&f800 &2f8 (760 bytes) ;; &fd08-&ffff &2f8 bytes ;; 20344 bytes free. org &7e00 start: di ld sp,&ffff ld hl,&c9fb ld (&0038),hl ei ld hl,&188 ld d,&aa call cls ld hl,&8188 ld d,&55 call cls ld hl,crtc_vals call set_screen flip equ &0cc4 XOR &2cc4 flipl equ flip AND 255 fliph equ flip/256 fl: ld b,&f5 fl1: in a,(c) rra jr nc,fl1 ;; flip the screen ld hl,(base) ld bc,&bc0c out (c),c inc b out (c),h dec b inc c out (c),c inc b out (c),l halt halt halt ld a,(base+0) xor flipl ld (base+0),a ld a,(base+1) xor fliph ld (base+1),a jp fl cls: ld bc,32*8 cls1: push de push bc push hl ld (hl),d ld e,l ld d,h inc de ld bc,46*2-1 ldir pop hl call _cpc_NextLineInternal pop bc pop de dec bc ld a,b or c jr nz,cls1 ret base: defw &0cc4 set_screen: ld de,&bcbe xor a ss1: ld b,d out (c),a ld b,e outi inc a cp 14 jr nz,ss1 ret ;; HL = address _cpc_NextLineInternal: ;; go down next scan line ld a,h add a,8 ld h,a ;; check if we should go to next char line and &38 ret nz ;; remove effect of last add ld a,h sub &8 ld h,a ;; add on amount to go to next char line ld a,l add a,46*2 ld l,a ld a,h adc a,&00 ld h,a ;; if we overflowed to next 16k the result will be 0 and &38 ret z ;; we didn't overflow adjust to go back into 1st 16k ld a,h sub &38 ld h,a ret crtc_vals: defb &03f, 46,49, &086, &026, 0, 32, 35,0,8-1,0,0,&0c,196 end start