; Monday 16-Mar-92 00:28:00 * === RNC_1.SRC ================================================================= * * Cartridge File RNC Unpack Routines (Method 1) -- Handy Software * * Copyright (c) 1992 Rob Northen Computing, Tel. (UK) 0428-713635 * * Date Name Description * --------- ----------- -------------------------------------------------------- * 16 Mar 92 R.Northen Created this file! * * ============================================================================== ; Use PP.EXE to pack a raw data file or Epyx .BIN file using Method 1 or 2 ; ; Use RNC_1.SRC to unpack Method 1 RNC packed files, OR ; ; Use RNC_2.SRC to unpack Method 2 RNC packed files ; ; Call READFILERNC macro to unpack a packed file, in the same way as you ; ; would call the READFILE macro to read an unpacked file ; ; Use HANDYROM to assemble .BIN or raw data files into a Cart ROM image ; BEGIN_ZPAGE cartdat .DS 2 counts .DS 2 blocks .DS 1 rncdat .DS 4 hufftab .DS 2 bitbufl .DS 2 bitbufh .DS 2 bufbits .DS 1 bitlen .DS 1 hufcde .DS 2 hufbse .DS 2 temp1 .DS 1 temp2 .DS 1 temp3 .DS 1 END_ZPAGE rawtab .DS $80 postab .DS $80 slntab .DS $80 tmptab .DS $10 #MACRO GETCARTBYTE lda RCART_0 inc CartOffsetLow bne ??.0 jsr NextCartPage ??.0 .eq * #ENDMACRO GetCartByteSub lda RCART_0 inc CartOffsetLow bne NextCartPage2 NextCartPage * ****************************************************************************** * update high byte of cart page counter and if zero update cart page * ON EXIT: * - all registers are preserved * ****************************************************************************** #IF ROMPAGESIZE>256 inc CartOffsetHigh bne NextCartPage2 #ENDIF pha phx phy inc CartPage lda CartPage jsr SetCartPage lda #<{-ROMPAGESIZE} sta CartOffsetLow #if ROMPAGESIZE>256 lda #>{-ROMPAGESIZE} sta CartOffsetHigh #ENDIF ply plx pla NextCartPage2 rts ReadFile0RNC * *************************************************************************** * This routine will unpack into RAM a Packed game cartridge file. Presumes * that the cartridge 0 port is all set up to start reading. Also presumes * that sysptr points to the directory entry of the file to be loaded, that the * CartDirectory buffer is filled out, and that CartPage and * CartOffsetLow,High reflect the state of port 0. * * ON ENTRY: * - If you have specified that the file directory has a ROMDIR_DEST field * which specifies that the directory has a RAM destination field: * If the A register is non-zero, X,Y (low,high) is presumed to have * the RAM destination for the file; if A is zero, then the RAM * destination is taken from the directory entry * - If you have not specified that the file directory has a ROMDIR_DEST * field you must specify RAM destination of the file: * X,Y (low,high) has the RAM destination for the file * - The cartridge 0 port is all set up to read the first byte of the file * * ON EXIT: * - CartPage and CartOffsetLow,High are advanced to the byte beyond * the last byte read * - X,Y (low,high) has RAM address of the byte beyond the last written #IFDEF ROMDIR_DEST cmp #1 bcs .99 ldx CartDirectory+ROMDIR_DEST ; get RAM destination from directory ldy CartDirectory+ROMDIR_DEST+1 #ENDIF .99 STX sysptr ; X,Y has the RAM destination pointer STY sysptr+1 SET_TO_READ_CART #IF ROMPAGESIZE>256 sec ; set Y to complement of CartOffsetHigh lda CartOffsetHigh ; to facilitate bounds checking sbc #>ROMPAGESIZE sta CartOffsetHigh #ENDIF ldy #18 .00 jsr GetCartByteSub dey bne .00 sta blocks stz bufbits jsr GetCartByteSub sta bitbufl jsr GetCartByteSub sta bitbufl+1 ldx #2 jsr GetBitsX .01 lda #rawtab sta hufftab+1 jsr MakeHuff lda #postab sta hufftab+1 jsr MakeHuff lda #slntab sta hufftab+1 jsr MakeHuff ldx #16 jsr GetBitsX ldy rncdat+1 ldx rncdat beq .02 iny .02 stx counts sty counts+1 jmp .10 .03 lda #postab sta hufftab+1 jsr GetVal lda sysptr clc sbc rncdat sta temp1 lda sysptr+1 sbc rncdat+1 sta temp2 lda #slntab sta hufftab+1 jsr GetVal ldy rncdat+1 lda rncdat clc adc #2 beq .04 iny .04 bcc .05 iny .05 tax sty rncdat+1 ldy #0 .06 lda (temp1),y sta (sysptr),y iny beq .08 .07 dex bne .06 dec rncdat+1 bne .06 bra .09 .08 inc temp2 inc sysptr+1 bra .07 .09 tya clc adc sysptr sta sysptr bcc .10 inc sysptr+1 .10 lda #rawtab sta hufftab+1 jsr GetVal lda rncdat ora rncdat+1 bne .11 jmp .22 .11 ldy rncdat+1 ldx rncdat beq .12 iny .12 sty rncdat+1 ldy #0 .13 cpy #2 beq .14 lda cartdat,y sta (sysptr),y iny dex bne .13 dec rncdat+1 bne .13 cpy #2 beq .17 lda cartdat+1 bra .18 .14 GETCARTBYTE sta (sysptr),y iny beq .16 .15 dex bne .14 dec rncdat+1 bne .14 bra .17 .16 inc sysptr+1 bra .15 .17 jsr GetCartByteSub .18 sta temp1 sta cartdat jsr GetCartByteSub sta temp2 sta cartdat+1 tya clc adc sysptr sta sysptr bcc .19 inc sysptr+1 .19 stz bitbufh stz bitbufh+1 ldy bufbits beq .21 .20 asl temp1 rol temp2 rol bitbufh rol bitbufh+1 dey bne .20 ldy bufbits .21 lda msktabl,y and bitbufl ora temp1 sta bitbufl lda msktabh,y and bitbufl+1 ora temp2 sta bitbufl+1 .22 dec counts bne .23 dec counts+1 beq .24 .23 jmp .03 .24 dec blocks beq .25 jmp .01 .25 #IF ROMPAGESIZE>256 lda CartOffsetHigh clc adc #>ROMPAGESIZE sta CartOffsetHigh #ENDIF ldx sysptr ldy sysptr+1 jmp RestoreReturn * ****************************************************************************** GetVal ldy #$ff GetVal2 iny GetVal3 lda (hufftab),y iny and bitbufl sta rncdat lda (hufftab),y iny and bitbufl+1 sta rncdat+1 lda (hufftab),y iny cmp rncdat bne GetVal2 lda (hufftab),y iny cmp rncdat+1 bne GetVal3 tya adc #{15*4-1} tay lda (hufftab),y pha iny lda (hufftab),y jsr GetBits pla cmp #2 bcs GetVal4 sta rncdat stz rncdat+1 rts GetVal4 sbc #1 pha jsr GetBits pla tay cpy #8 bcc GetVal5 lda bittabl-8,y ora rncdat+1 sta rncdat+1 rts GetVal5 lda bittabl,y ora rncdat sta rncdat rts bittabl .BY 1 .BY 2 .BY 4 .BY 8 .BY 16 .BY 32 .BY 64 .BY 128 * ****************************************************************************** GetBits tax GetBitsX lda msktabl,x and bitbufl sta rncdat lda msktabh,x and bitbufl+1 sta rncdat+1 lda bufbits bne GetBits4 GetBits3 jsr GetCartByteSub sta cartdat sta bitbufh jsr GetCartByteSub sta cartdat+1 sta bitbufh+1 lda #16 sta bufbits GetBits4 lsr bitbufh+1 ror bitbufh ror bitbufl+1 ror bitbufl dex beq GetBits5 dec bufbits bne GetBits4 beq GetBits3 GetBits5 dec bufbits GetBits6 rts msktabl .BY 0 .BY 1 .BY 3 .BY 7 .BY 15 .BY 31 .BY 63 .BY 127 .BY 255 .BY 255 .BY 255 .BY 255 .BY 255 .BY 255 .BY 255 .BY 255 .BY 255 msktabh .BY 0 .BY 0 .BY 0 .BY 0 .BY 0 .BY 0 .BY 0 .BY 0 .BY 0 .BY 1 .BY 3 .BY 7 .BY 15 .BY 31 .BY 63 .BY 127 .BY 255 * ****************************************************************************** MakeHuff ldx #5 jsr GetBitsX lda rncdat beq GetBits6 sta temp1 sta temp2 ldy #0 MakeHuff2 phy ldx #4 jsr GetBitsX ply lda rncdat sta tmptab,y iny dec temp2 bne MakeHuff2 ldy #1 sty bitlen dey sty hufcde sty hufcde+1 sty hufbse lda #$80 sta hufbse+1 MakeHuff3 lda temp1 sta temp2 stz temp3 MakeHuff4 lda bitlen ldx temp3 cmp tmptab,x bne MakeHuff8 tax lda msktabl,x sta (hufftab),y iny lda msktabh,x sta (hufftab),y iny lda hufcde sta rncdat+2 lda hufcde+1 sta rncdat+3 MakeHuff5 asl rncdat+2 rol rncdat+3 ror rncdat+1 ror rncdat dex bne MakeHuff5 lda #16 sec sbc bitlen beq MakeHuff7 tax MakeHuff6 lsr rncdat+1 ror rncdat dex bne MakeHuff6 MakeHuff7 lda rncdat sta (hufftab),y iny lda rncdat+1 sta (hufftab),y iny tya pha clc adc #{15*4} tay lda temp3 sta (hufftab),y iny lda bitlen sta (hufftab),y pla tay lda hufbse clc adc hufcde sta hufcde lda hufbse+1 adc hufcde+1 sta hufcde+1 MakeHuff8 inc temp3 dec temp2 bne MakeHuff4 lsr hufbse+1 ror hufbse inc bitlen lda bitlen cmp #17 bne MakeHuff3 rts