ORG &A000 ;init ROM disc LD C,7 LD DE,&40 LD HL,&B0FF CALL &BCCE LD SP,&BFFF ;la pile ;MODE 1 LD A,1 CALL &BC0E CALL ALL_BLACK CALL OUT_OVERSCAN boucle_debut CALL ALL_BLACK ;toutes les encres en noires LD A,"A" LD (nomfichier),A boucle_continue CALL LOADIMG LD HL,&C000 ;source LD DE,&200 ;destination CALL dzx0_turbo CALL affichage_palette CALL &BB03 CALL &BB06 LD A,(nomfichier) CP "V" ; dernière image atteinte ? JR Z,boucle_debut INC A LD (nomfichier),A CALL ALL_BLACK ;toutes les encres en noires JR boucle_continue RET affichage_palette ;encre 0 LD A,(&801) LD B,A LD C,B XOR A CALL &BC32 ;encre 1 LD A,(&802) LD B,A LD C,B LD A,1 CALL &BC32 ;encre 2 LD A,(&803) LD B,A LD C,B LD A,2 CALL &BC32 ;encre 3 LD A,(&804) LD B,A LD C,B LD A,3 CALL &BC32 CALL &BD19 RET ; ----------------------------------------------------------------------------- ; Chargement a l'écran de l'image compressée ; ----------------------------------------------------------------------------- LOADIMG ;vider l'écran LD HL,&C000 LD DE,&C001 LD BC,&3FFF LD (HL),0 LDIR ;charger le fichier LD B,5 LD HL,nomfichier LD DE,&A400 CALL &BC77 LD HL,&C000 CALL &BC83 CALL &BC7A RET nomfichier DEFM "A.ZX0" ; ----------------------------------------------------------------------------- ; toutes les encres noires ; ----------------------------------------------------------------------------- ALL_BLACK XOR A LD BC,0 CALL &BC32 LD A,1 LD BC,0 CALL &BC32 LD A,2 LD BC,0 CALL &BC32 LD A,3 LD BC,0 CALL &BC32 CALL &BD19 RET ; ----------------------------------------------------------------------------- ; OUT OVERSCAN ; ----------------------------------------------------------------------------- OUT_OVERSCAN ;largeur LD BC,&BC01 OUT (C),C LD BC,&BD30 OUT (C),C ;hauteur LD BC,&BC06 OUT (C),C LD BC,&BD22 OUT (C),C ;decalage horizontal LD BC,&BC02 OUT (C),C LD BC,&BD32 OUT (C),C ;decalage vertical LD BC,&BC07 OUT (C),C LD BC,&BD23 OUT (C),C ;compatibilité CRTC 2 LD BC,&BC03 OUT (C),C LD BC,&BD06 OUT (C),C ;ecran 32 ko (&0000 a &7FFF) LD BC,&BC0C OUT (C),C LD BC,&BD0D OUT (C),C ;debut offset (en &0200) LD BC,&BC0D OUT (C),C LD BC,&BD00 OUT (C),C RET ;------------------------------------------------------------------------------ ; Decompactage ZX0 v2.0 ;------------------------------------------------------------------------------ dzx0_turbo LD BC, &FFFF ; preserve default offset 1 LD (dzx0t_last_offset+1), BC INC BC LD A, &80 JR dzx0t_literals dzx0t_new_offset LD C, &FE ; prepare negative offset ADD A, A JP NZ, dzx0t_new_offset_skip LD A, (HL) ; load another group of 8 bits INC HL RLA dzx0t_new_offset_skip CALL NC, dzx0t_elias ; obtain offset MSB INC C RET Z ; check end marker LD B, C LD C, (HL) ; obtain offset LSB INC HL RR B ; last offset bit becomes first length bit RR C LD (dzx0t_last_offset+1), BC ; preserve new offset LD BC, 1 ; obtain length CALL NC, dzx0t_elias INC BC dzx0t_copy PUSH HL ; preserve source dzx0t_last_offset LD HL, 0 ; restore offset ADD HL, DE ; calculate destination - offset LDIR ; copy from offset POP HL ; restore source ADD A, A ; copy from literals or new offset? JR C, dzx0t_new_offset dzx0t_literals INC C ; obtain length ADD A, A JP NZ, dzx0t_literals_skip LD A, (HL) ; load another group of 8 bits INC HL RLA dzx0t_literals_skip CALL NC, dzx0t_elias LDIR ; copy literals ADD A, A ; copy from last offset or new offset? JR C, dzx0t_new_offset INC C ; obtain length ADD A, A JP NZ, dzx0t_last_offset_skip LD A, (HL) ; load another group of 8 bits INC HL RLA dzx0t_last_offset_skip CALL NC, dzx0t_elias JP dzx0t_copy dzx0t_elias ADD A, A ; interlaced Elias gamma coding RL C ADD A, A JR NC, dzx0t_elias RET NZ LD A, (HL) ; load another group of 8 bits INC HL RLA RET C ADD A, A RL C ADD A, A RET C ADD A, A RL C ADD A, A RET C ADD A, A RL C ADD A, A RET C dzx0t_elias_loop ADD A, A RL C RL B ADD A, A JR NC, dzx0t_elias_loop RET NZ LD A, (HL) ; load another group of 8 bits INC HL RLA JR NC, dzx0t_elias_loop RET