;------------------------------------------------------------------------------ ; EXOMIZER 2.09 Z80 DECODER BY METALBRAIN AND OPTIMIZED BY ANTONIO VILLENA ; COMPRESSION ALGORITHM BY MAGNUS LIND ; ; INPUT HL = COMPRESSED DATA START ; DE = UNCOMPRESSED DESTINATION START ; EXO_MAPBASEBITS = BUFFER OF 156 BYTES ;------------------------------------------------------------------------------ EXO_MAPBASEBITS EQU &A000 ORG #8000 LD H,(IX+3) LD L,(IX+2) LD D,(IX+1) LD E,(IX+0) DI CALL EXO_DEEXO EI RET EXO_DEEXO LD IY, EXO_MAPBASEBITS LD A, (HL) INC HL LD B,52 PUSH DE EXO_INITBITS EX AF,AF' LD A,B SUB 4 AND 15 JR NZ,EXO_NODE1 LD DE,1 ;DE=B2 EXO_NODE1 LD C,16 EX AF,AF' EXO_GET4BITS CALL EXO_GETBIT RL C JR NC,EXO_GET4BITS LD (IY+0),C ;BITS[I]=B1 PUSH HL LD HL, 1 DEFB 210 ;3 BYTES NOP (JP NC) EXO_SETBIT ADD HL,HL DEC C JR NZ,EXO_SETBIT LD (IY+52),E LD (IY+104),D ;BASE[I]=B2 ADD HL,DE EX DE,HL INC IY POP HL DJNZ EXO_INITBITS POP DE DB 218 ;3 BYTES NOP (JP C) --> JR EXO_MAINLOOP EXO_LITERALCOPY LDIR EXO_MAINLOOP LD C,1 ;LENGHT=1 CALL EXO_GETBIT ;LITERAL? JR C,EXO_LITERALCOPY LD C,255 EXO_GETINDEX INC C CALL EXO_GETBIT JR NC,EXO_GETINDEX BIT 4,C JR Z, EXO_CONTINUE BIT 0,C RET Z PUSH DE LD D,16 CALL EXO_GETBITS POP DE JR EXO_LITERALCOPY EXO_CONTINUE PUSH DE CALL EXO_GETPAIR PUSH BC POP IX LD DE,512+48 ;2 BITS, 48 OFFSET INC B DJNZ EXO_DONTGO DEC C JR Z, EXO_GOFORIT DEC C ;2? EXO_DONTGO LD DE,1024+32 ;4 BITS, 32 OFFSET JR Z,EXO_GOFORIT LD E,16 ;16 OFFSET EXO_GOFORIT CALL EXO_GETBITS EX AF,AF' LD A,E ADD A,C LD C,A EX AF,AF' CALL EXO_GETPAIR POP DE ;BC=OFFSET PUSH HL ;DE=DESTINATION LD H,D LD L,E SBC HL,BC ;HL=ORIGIN PUSH IX POP BC ;BC=LENGHT LDIR POP HL ;KEEP HL, DE IS UPDATED JR EXO_MAINLOOP ;NEXT! EXO_GETPAIR LD IY,EXO_MAPBASEBITS LD B,0 ADD IY,BC LD D,(IY+0) CALL EXO_GETBITS PUSH HL LD L,(IY+52) LD H,(IY+104) ADD HL,BC ;ALWAYS CLEAR C FLAG LD B,H LD C,L POP HL RET EXO_GETBITS LD BC,0 ;GET D BITS IN BC EXO_GETTINGBITS DEC D RET M CALL EXO_GETBIT RL C RL B JR EXO_GETTINGBITS EXO_GETBIT SRL A ;GET ONE BIT RET NZ LD A,(HL) INC HL RRA RET