Mega Magazine 5

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Text File | 1988-09-01 | 6KB | 418 lines

************************************* * * * THE HTT GIGA UNPACKER * * (C)1990 BY FRANKENSTEIN * * * ************************************* * * * VERSION: 5.7 DATE: 19-11-90 * * * ************************************* * USED FOR THE EXPO DEMO 1991 *------------------------------------ * DOCUMENTED/TRANSLATED AT 1-1-93 (!) *------------------------------------ ORG $B000 * START OF PACKED DATA PACKBEG EQU $46F2 * END OF PACKED DATA + 1 !! * (PHYSICAL END) PACKEND EQU $5000 *------------------------------------ * PROGRAM VARIABLES *------------------------------------ * 3 PAGES BUFFER FOR THE TREE TREE1 EQU $B900 * BITPAT.L TREE2 EQU $BA00 * BITPAT.H TREE3 EQU $BB00 * CHAR. * WARNING! THIS IS A SMALL BUFFER! MTAB1 EQU ENDPRG+1 * BUFFER MTAB2 EQU ENDPRG+1+16 * BUFFER SOURCE EQU $F0 (AND $F1) TARGET EQU $F2 (AND $F3) EIND EQU $F4 (AND $F5) FINDBEG EQU $F6 FINDEND EQU $F7 BINBEG EQU $F8 BINEND EQU $F9 SRCBIT EQU $FA TREELEN EQU $FB DUMMY1 EQU $FC DUMMY2 EQU $FD SBCNT EQU $FE * SOURCE BIT COUNT. * INTERRUPTS OFF! LDA #0 STA $D40E STA $D20E LDA #DL STA $230 STA $D402 LDA #DL/256 STA $231 STA $D403 LDA #34 STA $D400 *------------------------------------ * SET BEGIN & END POINTERS *------------------------------------ LDA #PACKBEG:L STA SOURCE LDA #PACKBEG:H STA SOURCE+1 LDA #PACKEND:L STA EIND LDA #PACKEND:H STA EIND+1 *------------------------------------ * CREATE TWO MASK TABLES *------------------------------------ LDX #31 LDA #0 DELTAB STA MTAB1,X DEX BPL DELTAB LDX #7 LDA #1 FILTAB STA MTAB1,X STA MTAB2+8,X ASL DEX BPL FILTAB *------------------------------------ * CLEAR TREE BUFFER *------------------------------------ INX TXA DELBUF STA TREE1,X STA TREE2,X STA TREE3,X INX BNE DELBUF *------------------------------------ * GET HEADER BYTES *------------------------------------ * BYTE #1: \ LO/HI * BYTE #2: / ORIGINAL START ADR. * BYTE #3: LENGTH TREE TABEL * [TREE] * [DATA] TAY ;Y=0 LDA (SOURCE),Y STA TARGET INY LDA (SOURCE),Y STA TARGET+1 INY LDA (SOURCE),Y STA TREELEN *------------------------------------ * COPY TREE IN SEPARATE PAGES *------------------------------------ LDX #0 CTREE LDA #3 JSR ADDSRC LDY #0 LDA (SOURCE),Y STA TREE1,X INY LDA (SOURCE),Y STA TREE2,X INY LDA (SOURCE),Y STA TREE3,X INX CPX TREELEN BNE CTREE * IF TREELEN = 0 (=256!) * THEN THE ENDVECTOR IS 255 DEC TREELEN LDA #3 JSR ADDSRC *------------------------------------ * INITIALISATION *------------------------------------ LDX #0 NOTSET INX LDA TREE1,X AND #%10000000 BEQ NOTSET STX BEGEEN+1 * GET TWO BYTES FROM SOURCE * SOURCE BIT COUNTER = 0 JSR NEXTWO *------------------------------------ * MAIN LOOP *------------------------------------ * TREE BIT COUNTER = 0 * (X = TREE BIT COUNTER) * FINDBEG = BEGIN TREE-TABEL * FINDEND = END TREE-TABEL MAIN LDX #0 STX FINDBEG LDA TREELEN STA FINDEND *------------------------------------ * SEARCH LOOP *------------------------------------ * FILTER A BIT FROM DUMMY1, DUMMY2 * WITH HELP OF THE MASK CHOSEN * BY THE SOURCE BIT COUNTER. * "ORA" THE RESULT AND PUT IT * IN SRCBIT SEARCH LDY SBCNT LDA DUMMY1 AND MTAB1,Y STA SRCBIT LDA DUMMY2 AND MTAB2,Y ORA SRCBIT STA SRCBIT * RESET BINAIRY SEARCH POINTERS LDA FINDBEG STA BINBEG LDA FINDEND STA BINEND * IF THE TREE BIT COUNTER >7 THEN * CHECK THE HI-BYTE OF THE TREE-TABEL TXA BNE NOT1COL BEGEEN LDY #0 JMP SKIP NOT1COL AND #%00001000 BEQ LOCHK *------------------------------------ * CHECK TREE HI-BYTE *------------------------------------ LDA MTAB2,X STA HMASK+1 HINEX LDA BINBEG CLC ADC BINEND ROR TAY LDA TREE2,Y HMASK AND #0 BNE EEN2 STY BINBEG INY CPY BINEND BNE HINEX JMP SKIP EEN2 STY BINEND DEY CPY BINBEG BNE HINEX INY JMP SKIP *------------------------------------ * CHECK LO-BYTE TREE *------------------------------------ LOCHK LDA MTAB1,X STA LMASK+1 LONEX LDA BINBEG CLC ADC BINEND ROR TAY LDA TREE1,Y LMASK AND #0 BNE EEN STY BINBEG INY CPY BINEND BNE LONEX JMP SKIP EEN STY BINEND DEY CPY BINBEG BNE LONEX INY * IF WE'RE LOOKING FOR A "0", THEN * WE HAVE TO MOVE * THE FINDEND POINTER SKIP LDA SRCBIT BNE NOZERO DEY STY FINDEND JMP CONTIN * IF WE'RE LOOKING FOR A "1", THEN * WE HAVE TO MOVE * THE FINDBEG POINTER NOZERO STY FINDBEG * INC. TREE BIT COUNTER (X = X + 1) * INC. SOURCE BIT COUNTER (SBCNT) CONTIN INX INC SBCNT * SOURCE BIT COUNTER > 15? LDA SBCNT CMP #16 BNE NOEND * SOURCE BIT COUNTER = 0 * DUMMY1, DUMMY2 = NEXT TWO * BYTES FROM SOURCE LDA #2 JSR ADDSRC JSR NEXTWO * UNTIL FINDBEG = FINDEND NOEND LDA FINDBEG CMP FINDEND BEQ PUTCH JMP SEARCH * GET A CHARACTER FROM THE TREE-TABEL * WITH HELP OF THE FINDBEG POINTER * AND PUT IT IN TARGET PUTCH TAX LDA TREE3,X LDY #0 STA (TARGET),Y STA $D01A *------------------------------------ * INC. TARGET POINTER *------------------------------------ INC TARGET BNE NOTHI * IF YOU WANT TO INCLUDE A * "PAGES UNPACKED" COUNTER, * HERE'S THE PLACE TO DO IT! INC TARGET+1 NOTHI LDA TARGET CMP EIND BNE NOTHEND LDA TARGET+1 CMP EIND+1 BEQ STOPIT * NOT THE END, BACK TO MAIN! NOTHEND JMP MAIN * END OF DECRUNCH STOPIT LDA #$C0 STA $D20E LDA #$40 STA $D40E LDA #0 STA 559 RTS *------------------------------------ * ADD ACCU TO SOURCE POINTER *------------------------------------ ADDSRC CLC ADC SOURCE STA SOURCE BCC CEMPT INC SOURCE+1 CEMPT RTS *------------------------------------ * GET TWO NEW BYTES FROM SOURCE *------------------------------------ NEXTWO LDY #0 STY SBCNT LDA (SOURCE),Y STA DUMMY1 INY LDA (SOURCE),Y STA DUMMY2 RTS ASC %(C)FRANKENSTEIN% DL DFB 112,112 DFB $42 DFW TXT DFB $41 DFW DL TXT ASC %HTT GIGA UNPACKER - % ASC %IT'S SLOW, BUT GOOD!% ENDPRG DFB 0¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯