Short: Blitter-MFM-Coder by Cruncher/ACUME Author: Daniel Adler Uploader: aminet aminet net Type: util/pack Version: 1.0 Architecture: m68k-amigaos BLITTER-MFM-CODER V.1.0 DOC by CRUNCHER/ACUME (c)'92 by ACUME Release Date 30/4/92 This Utility could be used to code files to an format,which is necessary for decoding datas,which are loaded with an own Trackloader.These Datas can be decoded EASY AND FAST with the BLITTER ! But the Datas must be saved in the MFM-Format on Disk before decoding ! I'll give the instruction how to decode the datas in your own sourcecode. Example: The Datas before coding in BLITTER-MFM Format : %01100111010110001100101011110000 The Datas in BLITTER-MFM Format : %0 1 0 1 0 0 1 0 1 0 1 1 1 1 0 0 ; All Even bits are linked together and % 1 0 1 1 1 1 0 0 1 0 0 0 1 1 0 0 ; All Odd bits are linked together = %0101001010111100 1011110010001100 EVEN ODD To decode it,you use the Blitter : Set the EVEN Datas in BLITTER-A ADDRESS (BLTAPT ) Set the ODD Datas in BLITTER-B ADDRESS (BLTBPT ) Set BLITTER-C DATA to %1010101010101010 (BLTCDAT) Set the Destination Address in BLITTER-D ADDRESS (BLTDPT ) Turn on A,B,D BLITTER-CHANNELS ON (BLTCON0) Turn off C BLITTER-CHANNELS OFF (BLTCON0) Set Shift of B on 1 (BLTCON1) Set Shift of A on 0 (BLTCON0) Set Modulos A,B,D on 0 (BLTxMOD) Set Term %11011000 (BLTCON0) Set A-Masks on $ffff (BLTAxWM) Set Size correct to the file,if the datas are too long for one blit, start the blitter some more times ! move.l #EvenAdr,$dff050 move.l #OddAdr,$dff04c move.l #DestAdr,$dff066 move.w #%1010101010101010,$dff070 clr $dff064 clr $dff062 clr $dff066 move.w #%0000110111011000,$dff040 move.w #%1000000000000000,$dff042 move.w #$ffff,$dff044 move.w #$ffff,$dff046 move.w Size,$dff058 So thats it ! If there is a big bug or do you have problems , contact me ! CRUNCHER/ACUME (Coder,Gfx) Daniel Adler Beethovenstr.6 3400 Goettingen +49(0)551-44623 Contact me also for swapping LEGAL stuff,friendship,cool chats ! Greetinx to EQUI,SIR,ROLLI,ROGER WILCO,DRAGON,HARDBALL,RED KNIGHT,NOX,SMASH ALL OTHER ACUME MEMBERS AND ALL OTHER CONTACTS !!!!!!!!!!!!!!!!