Blackthorne (SNES) - Type of compression for font?

Started by RodMerida, October 05, 2020, 07:00:53 AM

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RodMerida

October 05, 2020, 07:00:53 AM Last Edit: October 05, 2020, 07:20:29 PM by RodMerida
Hello.
I'm interested to be able to access the font of Blacthorne / Blackhawk for SNES, in order to fulfill a translation (I need to add accented letters and that kind). But it doesn't matter how much I search the font graphics inside the ROM with a tile editor, they don't seem to appear; so it's very probable they are compressed.

Does anybody know the kind of compression format this game uses, and the exact address of such font?
Thank you.

slidelljohn

#1
October 09, 2020, 01:23:36 AM
Looks like a sliding window compression but I could be wrong.

Code Select

$84:B727-$84:B976 //font compressed data
============================================

$80/A197 A9 00 40    LDA #$4000              A:0084 X:B727 Y:B727 D:0000 DB:00 S:01F5 P:eNvmxdIzcHC:0236 VC:008 00 FL:04
$80/A19A 85 36       STA $36    [$00:0036]   A:4000 X:B727 Y:B727 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0254 VC:008 00 FL:04
$80/A19C A9 7E 00    LDA #$007E              A:4000 X:B727 Y:B727 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0282 VC:008 00 FL:04
$80/A19F 85 38       STA $38    [$00:0038]   A:007E X:B727 Y:B727 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0300 VC:008 00 FL:04
$80/A1A1 B7 2E       LDA [$2E],y[$84:B727]   A:007E X:B727 Y:B727 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0352 VC:008 00 FL:04 //start of compressed data
$80/A1A3 C8          INY                     A:0400 X:B727 Y:B727 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0400 VC:008 00 FL:04 //0x400 decompression size
.......
.......
.......
$80/A23D B7 2E       LDA [$2E],y[$84:B975]   A:0102 X:03FC Y:B975 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0298 VC:012 00 FL:04
$80/A23F 85 4C       STA $4C    [$00:004C]   A:0179 X:03FC Y:B975 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0340 VC:012 00 FL:04
$80/A241 C8          INY                     A:0179 X:03FC Y:B975 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0360 VC:012 00 FL:04
$80/A242 F0 43       BEQ $43    [$A287]      A:0179 X:03FC Y:B976 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0372 VC:012 00 FL:04
$80/A244 B7 2E       LDA [$2E],y[$84:B976]   A:0179 X:03FC Y:B976 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0408 VC:012 00 FL:04 //end of compressed data
$80/A246 85 4D       STA $4D    [$00:004D]   A:0110 X:03FC Y:B976 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0450 VC:012 00 FL:04
$80/A248 C8          INY                     A:0110 X:03FC Y:B976 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0470 VC:012 00 FL:04
$80/A249 F0 43       BEQ $43    [$A28E]      A:0110 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0482 VC:012 00 FL:04
$80/A24B 84 20       STY $20    [$00:0020]   A:0110 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0494 VC:012 00 FL:04
$80/A24D C2 20       REP #$20                A:0110 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0522 VC:012 00 FL:04
$80/A24F A5 4C       LDA $4C    [$00:004C]   A:0110 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:eNvmxdIzcHC:0540 VC:012 00 FL:04
$80/A251 29 FF 0F    AND #$0FFF              A:1079 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0568 VC:012 00 FL:04
$80/A254 A8          TAY                     A:0079 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0586 VC:012 00 FL:04
$80/A255 A5 4C       LDA $4C    [$00:004C]   A:0079 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0598 VC:012 00 FL:04
$80/A257 29 00 F0    AND #$F000              A:1079 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0626 VC:012 00 FL:04
$80/A25A 0A          ASL A                   A:1000 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0644 VC:012 00 FL:04
$80/A25B 2A          ROL A                   A:2000 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0656 VC:012 00 FL:04
$80/A25C 2A          ROL A                   A:4000 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0668 VC:012 00 FL:04
$80/A25D 2A          ROL A                   A:8000 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:eNvmxdIzcHC:0680 VC:012 00 FL:04
$80/A25E 2A          ROL A                   A:0000 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIZCHC:0692 VC:012 00 FL:04
$80/A25F 69 03 00    ADC #$0003              A:0001 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0704 VC:012 00 FL:04
$80/A262 85 4C       STA $4C    [$00:004C]   A:0004 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0722 VC:012 00 FL:04
$80/A264 98          TYA                     A:0004 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0750 VC:012 00 FL:04
$80/A265 65 4C       ADC $4C    [$00:004C]   A:0079 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0762 VC:012 00 FL:04
$80/A267 29 FF 0F    AND #$0FFF              A:007D X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0790 VC:012 00 FL:04
$80/A26A 85 4C       STA $4C    [$00:004C]   A:007D X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0808 VC:012 00 FL:04
$80/A26C E2 20       SEP #$20                A:007D X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0836 VC:012 00 FL:04
$80/A26E B7 36       LDA [$36],y[$7E:4079]   A:007D X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0878 VC:012 00 FL:04
$80/A270 9F 00 40 7E STA $7E4000,x[$7E:43FC] A:00FF X:03FC Y:0079 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0922 VC:012 00 FL:04
$80/A274 C8          INY                     A:00FF X:03FC Y:0079 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0954 VC:012 00 FL:04
$80/A275 C0 00 10    CPY #$1000              A:00FF X:03FC Y:007A D:0000 DB:00 S:01F5 P:envMxdIzcHC:0966 VC:012 00 FL:04
$80/A278 F0 1B       BEQ $1B    [$A295]      A:00FF X:03FC Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0984 VC:012 00 FL:04
$80/A27A E8          INX                     A:00FF X:03FC Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0996 VC:012 00 FL:04
$80/A27B E4 4A       CPX $4A    [$00:004A]   A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:envMxdIzcHC:1008 VC:012 00 FL:04
$80/A27D F0 1B       BEQ $1B    [$A29A]      A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1036 VC:012 00 FL:04
$80/A27F C4 4C       CPY $4C    [$00:004C]   A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1048 VC:012 00 FL:04
$80/A281 D0 EB       BNE $EB    [$A26E]      A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1076 VC:012 00 FL:04
$80/A26E B7 36       LDA [$36],y[$7E:407A]   A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1118 VC:012 00 FL:04
$80/A270 9F 00 40 7E STA $7E4000,x[$7E:43FD] A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1162 VC:012 00 FL:04
$80/A274 C8          INY                     A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1194 VC:012 00 FL:04
$80/A275 C0 00 10    CPY #$1000              A:00FF X:03FD Y:007B D:0000 DB:00 S:01F5 P:envMxdIzcHC:1206 VC:012 00 FL:04
$80/A278 F0 1B       BEQ $1B    [$A295]      A:00FF X:03FD Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1224 VC:012 00 FL:04
$80/A27A E8          INX                     A:00FF X:03FD Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1236 VC:012 00 FL:04
$80/A27B E4 4A       CPX $4A    [$00:004A]   A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:envMxdIzcHC:1248 VC:012 00 FL:04
$80/A27D F0 1B       BEQ $1B    [$A29A]      A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1276 VC:012 00 FL:04
$80/A27F C4 4C       CPY $4C    [$00:004C]   A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1288 VC:012 00 FL:04
$80/A281 D0 EB       BNE $EB    [$A26E]      A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1316 VC:012 00 FL:04
$80/A26E B7 36       LDA [$36],y[$7E:407B]   A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1358 VC:012 00 FL:04
$80/A270 9F 00 40 7E STA $7E4000,x[$7E:43FE] A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0034 VC:013 00 FL:04
$80/A274 C8          INY                     A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0066 VC:013 00 FL:04
$80/A275 C0 00 10    CPY #$1000              A:00FF X:03FE Y:007C D:0000 DB:00 S:01F5 P:envMxdIzcHC:0078 VC:013 00 FL:04
$80/A278 F0 1B       BEQ $1B    [$A295]      A:00FF X:03FE Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0096 VC:013 00 FL:04
$80/A27A E8          INX                     A:00FF X:03FE Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0108 VC:013 00 FL:04
$80/A27B E4 4A       CPX $4A    [$00:004A]   A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:envMxdIzcHC:0120 VC:013 00 FL:04
$80/A27D F0 1B       BEQ $1B    [$A29A]      A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0148 VC:013 00 FL:04
$80/A27F C4 4C       CPY $4C    [$00:004C]   A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0160 VC:013 00 FL:04
$80/A281 D0 EB       BNE $EB    [$A26E]      A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0188 VC:013 00 FL:04
$80/A26E B7 36       LDA [$36],y[$7E:407C]   A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0230 VC:013 00 FL:04
$80/A270 9F 00 40 7E STA $7E4000,x[$7E:43FF] A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0274 VC:013 00 FL:04 //end of decompressed gfx
$80/A274 C8          INY                     A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0306 VC:013 00 FL:04
$80/A275 C0 00 10    CPY #$1000              A:00FF X:03FF Y:007D D:0000 DB:00 S:01F5 P:envMxdIzcHC:0318 VC:013 00 FL:04
$80/A278 F0 1B       BEQ $1B    [$A295]      A:00FF X:03FF Y:007D D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0336 VC:013 00 FL:04
$80/A27A E8          INX                     A:00FF X:03FF Y:007D D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0348 VC:013 00 FL:04
$80/A27B E4 4A       CPX $4A    [$00:004A]   A:00FF X:0400 Y:007D D:0000 DB:00 S:01F5 P:envMxdIzcHC:0360 VC:013 00 FL:04
$80/A27D F0 1B       BEQ $1B    [$A29A]      A:00FF X:0400 Y:007D D:0000 DB:00 S:01F5 P:envMxdIZCHC:0388 VC:013 00 FL:04
$80/A29A 20 A4 A2    JSR $A2A4  [$80:A2A4]   A:00FF X:0400 Y:007D D:0000 DB:00 S:01F5 P:envMxdIZCHC:0406 VC:013 00 FL:04 

RodMerida

#2
October 09, 2020, 12:41:40 PM
Quote from: slidelljohn on October 09, 2020, 01:23:36 AM
Looks like a sliding window compression but I could be wrong.

Code Select

$84:B727-$84:B976 //font compressed data
============================================

$80/A197 A9 00 40    LDA #$4000              A:0084 X:B727 Y:B727 D:0000 DB:00 S:01F5 P:eNvmxdIzcHC:0236 VC:008 00 FL:04
$80/A19A 85 36       STA $36    [$00:0036]   A:4000 X:B727 Y:B727 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0254 VC:008 00 FL:04
$80/A19C A9 7E 00    LDA #$007E              A:4000 X:B727 Y:B727 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0282 VC:008 00 FL:04
$80/A19F 85 38       STA $38    [$00:0038]   A:007E X:B727 Y:B727 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0300 VC:008 00 FL:04
$80/A1A1 B7 2E       LDA [$2E],y[$84:B727]   A:007E X:B727 Y:B727 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0352 VC:008 00 FL:04 //start of compressed data
$80/A1A3 C8          INY                     A:0400 X:B727 Y:B727 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0400 VC:008 00 FL:04 //0x400 decompression size
.......
.......
.......
$80/A23D B7 2E       LDA [$2E],y[$84:B975]   A:0102 X:03FC Y:B975 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0298 VC:012 00 FL:04
$80/A23F 85 4C       STA $4C    [$00:004C]   A:0179 X:03FC Y:B975 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0340 VC:012 00 FL:04
$80/A241 C8          INY                     A:0179 X:03FC Y:B975 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0360 VC:012 00 FL:04
$80/A242 F0 43       BEQ $43    [$A287]      A:0179 X:03FC Y:B976 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0372 VC:012 00 FL:04
$80/A244 B7 2E       LDA [$2E],y[$84:B976]   A:0179 X:03FC Y:B976 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0408 VC:012 00 FL:04 //end of compressed data
$80/A246 85 4D       STA $4D    [$00:004D]   A:0110 X:03FC Y:B976 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0450 VC:012 00 FL:04
$80/A248 C8          INY                     A:0110 X:03FC Y:B976 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0470 VC:012 00 FL:04
$80/A249 F0 43       BEQ $43    [$A28E]      A:0110 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0482 VC:012 00 FL:04
$80/A24B 84 20       STY $20    [$00:0020]   A:0110 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0494 VC:012 00 FL:04
$80/A24D C2 20       REP #$20                A:0110 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0522 VC:012 00 FL:04
$80/A24F A5 4C       LDA $4C    [$00:004C]   A:0110 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:eNvmxdIzcHC:0540 VC:012 00 FL:04
$80/A251 29 FF 0F    AND #$0FFF              A:1079 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0568 VC:012 00 FL:04
$80/A254 A8          TAY                     A:0079 X:03FC Y:B977 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0586 VC:012 00 FL:04
$80/A255 A5 4C       LDA $4C    [$00:004C]   A:0079 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0598 VC:012 00 FL:04
$80/A257 29 00 F0    AND #$F000              A:1079 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0626 VC:012 00 FL:04
$80/A25A 0A          ASL A                   A:1000 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0644 VC:012 00 FL:04
$80/A25B 2A          ROL A                   A:2000 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0656 VC:012 00 FL:04
$80/A25C 2A          ROL A                   A:4000 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0668 VC:012 00 FL:04
$80/A25D 2A          ROL A                   A:8000 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:eNvmxdIzcHC:0680 VC:012 00 FL:04
$80/A25E 2A          ROL A                   A:0000 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIZCHC:0692 VC:012 00 FL:04
$80/A25F 69 03 00    ADC #$0003              A:0001 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0704 VC:012 00 FL:04
$80/A262 85 4C       STA $4C    [$00:004C]   A:0004 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0722 VC:012 00 FL:04
$80/A264 98          TYA                     A:0004 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0750 VC:012 00 FL:04
$80/A265 65 4C       ADC $4C    [$00:004C]   A:0079 X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0762 VC:012 00 FL:04
$80/A267 29 FF 0F    AND #$0FFF              A:007D X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0790 VC:012 00 FL:04
$80/A26A 85 4C       STA $4C    [$00:004C]   A:007D X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0808 VC:012 00 FL:04
$80/A26C E2 20       SEP #$20                A:007D X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envmxdIzcHC:0836 VC:012 00 FL:04
$80/A26E B7 36       LDA [$36],y[$7E:4079]   A:007D X:03FC Y:0079 D:0000 DB:00 S:01F5 P:envMxdIzcHC:0878 VC:012 00 FL:04
$80/A270 9F 00 40 7E STA $7E4000,x[$7E:43FC] A:00FF X:03FC Y:0079 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0922 VC:012 00 FL:04
$80/A274 C8          INY                     A:00FF X:03FC Y:0079 D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0954 VC:012 00 FL:04
$80/A275 C0 00 10    CPY #$1000              A:00FF X:03FC Y:007A D:0000 DB:00 S:01F5 P:envMxdIzcHC:0966 VC:012 00 FL:04
$80/A278 F0 1B       BEQ $1B    [$A295]      A:00FF X:03FC Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0984 VC:012 00 FL:04
$80/A27A E8          INX                     A:00FF X:03FC Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0996 VC:012 00 FL:04
$80/A27B E4 4A       CPX $4A    [$00:004A]   A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:envMxdIzcHC:1008 VC:012 00 FL:04
$80/A27D F0 1B       BEQ $1B    [$A29A]      A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1036 VC:012 00 FL:04
$80/A27F C4 4C       CPY $4C    [$00:004C]   A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1048 VC:012 00 FL:04
$80/A281 D0 EB       BNE $EB    [$A26E]      A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1076 VC:012 00 FL:04
$80/A26E B7 36       LDA [$36],y[$7E:407A]   A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1118 VC:012 00 FL:04
$80/A270 9F 00 40 7E STA $7E4000,x[$7E:43FD] A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1162 VC:012 00 FL:04
$80/A274 C8          INY                     A:00FF X:03FD Y:007A D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1194 VC:012 00 FL:04
$80/A275 C0 00 10    CPY #$1000              A:00FF X:03FD Y:007B D:0000 DB:00 S:01F5 P:envMxdIzcHC:1206 VC:012 00 FL:04
$80/A278 F0 1B       BEQ $1B    [$A295]      A:00FF X:03FD Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1224 VC:012 00 FL:04
$80/A27A E8          INX                     A:00FF X:03FD Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1236 VC:012 00 FL:04
$80/A27B E4 4A       CPX $4A    [$00:004A]   A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:envMxdIzcHC:1248 VC:012 00 FL:04
$80/A27D F0 1B       BEQ $1B    [$A29A]      A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1276 VC:012 00 FL:04
$80/A27F C4 4C       CPY $4C    [$00:004C]   A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1288 VC:012 00 FL:04
$80/A281 D0 EB       BNE $EB    [$A26E]      A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1316 VC:012 00 FL:04
$80/A26E B7 36       LDA [$36],y[$7E:407B]   A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:1358 VC:012 00 FL:04
$80/A270 9F 00 40 7E STA $7E4000,x[$7E:43FE] A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0034 VC:013 00 FL:04
$80/A274 C8          INY                     A:00FF X:03FE Y:007B D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0066 VC:013 00 FL:04
$80/A275 C0 00 10    CPY #$1000              A:00FF X:03FE Y:007C D:0000 DB:00 S:01F5 P:envMxdIzcHC:0078 VC:013 00 FL:04
$80/A278 F0 1B       BEQ $1B    [$A295]      A:00FF X:03FE Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0096 VC:013 00 FL:04
$80/A27A E8          INX                     A:00FF X:03FE Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0108 VC:013 00 FL:04
$80/A27B E4 4A       CPX $4A    [$00:004A]   A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:envMxdIzcHC:0120 VC:013 00 FL:04
$80/A27D F0 1B       BEQ $1B    [$A29A]      A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0148 VC:013 00 FL:04
$80/A27F C4 4C       CPY $4C    [$00:004C]   A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0160 VC:013 00 FL:04
$80/A281 D0 EB       BNE $EB    [$A26E]      A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0188 VC:013 00 FL:04
$80/A26E B7 36       LDA [$36],y[$7E:407C]   A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0230 VC:013 00 FL:04
$80/A270 9F 00 40 7E STA $7E4000,x[$7E:43FF] A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0274 VC:013 00 FL:04 //end of decompressed gfx
$80/A274 C8          INY                     A:00FF X:03FF Y:007C D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0306 VC:013 00 FL:04
$80/A275 C0 00 10    CPY #$1000              A:00FF X:03FF Y:007D D:0000 DB:00 S:01F5 P:envMxdIzcHC:0318 VC:013 00 FL:04
$80/A278 F0 1B       BEQ $1B    [$A295]      A:00FF X:03FF Y:007D D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0336 VC:013 00 FL:04
$80/A27A E8          INX                     A:00FF X:03FF Y:007D D:0000 DB:00 S:01F5 P:eNvMxdIzcHC:0348 VC:013 00 FL:04
$80/A27B E4 4A       CPX $4A    [$00:004A]   A:00FF X:0400 Y:007D D:0000 DB:00 S:01F5 P:envMxdIzcHC:0360 VC:013 00 FL:04
$80/A27D F0 1B       BEQ $1B    [$A29A]      A:00FF X:0400 Y:007D D:0000 DB:00 S:01F5 P:envMxdIZCHC:0388 VC:013 00 FL:04
$80/A29A 20 A4 A2    JSR $A2A4  [$80:A2A4]   A:00FF X:0400 Y:007D D:0000 DB:00 S:01F5 P:envMxdIZCHC:0406 VC:013 00 FL:04 


Do you know any utility that is capable of uncompressing and recompressing whatever graphic bank by using this algorithm? Does such thing exist?

slidelljohn

#3
October 09, 2020, 05:55:27 PM
Sorry, but I do not know of a utility. I did take a look at the format and it is a simple
sliding window format. Do you have the file for the new font? I could get it compressed
for you if you do. :)

Code Select

dma from rom to ram
80:9F92 00   //from rom 0x1000 times without incrementing rom address
7e:4000      //to ram 0x1000 times with incrementing ram address

This 0x00's out 07e:4000-7e:4fff

compressed gfx format
xx xx = 2bytes = size

xx    = 1 byte of compression bit flags, 1's = no compression just load a byte, 0's = start sliding window compression

xx yx = 2 sliding window compression bytes, switch order to yx xx, y = y + 3 which is how many bytes to load
        x xx + 7e:4000 = sliding window position

RodMerida

#4
October 10, 2020, 10:30:37 AM
Thank you very much. Yes, I have it. I send it to you by private right now.

slidelljohn

#5
October 10, 2020, 11:29:39 PM

Here is a test program that can convert gfx to a usable format by never activating
the sliding widow 0 bits. It just uses the 1 bits to load non-compressed data. I
wont have time until probably next week to finish writing a exact compressor but
this should work for now for you to run some test with the graphics showing in game.
http://www.mediafire.com/file/2psp7fr0kcjcbsc/BlackthorneCompressor_Test.rar/file

Open your gfx that you want compressed (no larger than 0xfff) then compress and it will
create a usable file to place in the rom. What I did to test the gfx to make sure they loaded
was I put the gfx at 9f:f000 and the pointer is at 84:80a0. The pointer that I used was
00 70 1b. 84:8000 + 1b:7000 = 9f:f000.

RodMerida

#6
October 11, 2020, 03:59:01 AM Last Edit: October 11, 2020, 07:57:23 AM by RodMerida
Thank you very much.
October 11, 2020, 07:57:23 AM - (Auto Merged - Double Posts are not allowed before 7 days.)

Sorry, it doesn't work.
I'm trying to locate it in the ROM address D3500.
They are two font blocks, both of 400h characters. One is located at the ROM address 23727, whose pointer is 273700, and another located at the ROM address 23977, whose pointer is 773900. I change both pointers to 00350B and 90390B, and paste there both compressed chunks with your tool, but when I load the ROM everything looks screwed. If I only change the second pointer and keep the first one like it was before, the Interplay and Blizzard logo appears well, but the title screen appears screwed. When I press new game, the game looks well with the original font unchanged. 

slidelljohn

#7
October 11, 2020, 08:56:36 AM
"ROM address D3500"
This is not a rom address this is a pc address. D3500(pc) = $9A:B500(rom), $9A:B500 - 84:8000 = $16:3500
00 35 16 would be the pointer.

"I change both pointers to 00350B and 90390B"
These pointers do not look like they are correct.

RodMerida

#8
October 11, 2020, 09:29:17 AM Last Edit: October 11, 2020, 09:40:04 AM by RodMerida
Oh, what a mess.
^_^U

But now I understand!
That's why I couldn't find any address in the ROM lol
October 11, 2020, 09:40:04 AM - (Auto Merged - Double Posts are not allowed before 7 days.)

IT WORKS!!!!!!!!!!!!!!!!!!!
GREAT!!!!!!!!!!!
Yuhuuuuuuuuuu! LOL xD

After 5 days trying out! At last!

Thank you very much.

slidelljohn

#9
October 11, 2020, 11:29:41 PM
You're welcome my friend! :)

I figured the pictures would probably help. I'll let you know as soon as I finish writing
the exact compression with the sliding window. I have a few other things that I'm working
on and I have work tomorrow so maybe Tuesday or Wednesday Ill have time to get another
update for you.

RodMerida

#10
October 12, 2020, 10:03:39 PM
Even though I don't need it for this translation anymore because everything is working, I'm very courious now to be able know the exact compression format.

Also it could be useful for Lost Vikings 2 and these kind of games.

slidelljohn

#11
October 19, 2020, 04:58:57 PM Last Edit: October 19, 2020, 07:27:15 PM by slidelljohn
The exact format is:

1st 2 bytes is decompressed file size

Then 1 byte for 8 compression bit flags 76543210

bit flags are read one at a time starting at 0 then 1...7

if bit flag = 0 use a sliding window that has a size of no less than 3 and no more than 18
if bit flag = 1 load a non-compressed byte from file(this is what I used for the 1st test compressor which is why file was larger)

xx yx sliding window is 2 bytes in size xx is low byte yx is high byte

switch these to yx xx

x xx is the location that the sliding window starts

y is the size of the sliding window

if y = 0x0, sliding window has a size of 3
if y = 0xf, sliding window has a size of 18

Here is a example of the compressed gfx at $84:B727:

00 04 //size
FD    //compression flags, 0xfd = 1111 1101, read flags from right to left
FF    //bit flag = 1, store non-compressed byte from file
00 C0 //bit flag = 0, use sliding window, 00 = low c0 = high, switch to c0 00, 0x000 is window starting location, 0xc + 3 = size of window
3F    //bit flag = 1, store non-compressed byte from file
00    //bit flag = 1, store non-compressed byte from file
60    //bit flag = 1, store non-compressed byte from file
1F    //bit flag = 1, store non-compressed byte from file
5F    //bit flag = 1, store non-compressed byte from file
BF    //bit flag = 1, store non-compressed byte from file

This is the decompressed data:
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
3F 00 60 1F 5F BF

If 0x1000 bytes are stored 7e:4000-7e:4fff then dma those bytes to vram and then finish decompressing
start back over at 7e:4000.


So I was able to create the compressor with the sliding window that creates the same
exact compression size but some of the sliding window location are different. The ones that
are different are the ones that find multiple matches of the same values.

Here is a example of $84:B727 decompressed:
Code Select

FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
3F 00 60 1F 5F BF 7F BF 7F BF 7F BF 7F BF 7F BF
FF 00 00 FF FF FF FF FF FF FF FF FF FF FF FF FF
F8 00 04 F8 F2 FC FA FC FA FC FA FC FA FC FA FC
7F BF 7F BF 7F BF 7F BF 7F BF 7F BF 7F BF 7F BF
FA FC FA FC FA FC FA FC FA FC FA FC FA FC FA FC
7F BF 7F BF 7F BF 7F BF 5F BF 2F DF 1F 60 00 3F
FF FF FF FF FF FF FF FF FF FF FF FF FF 00 00 FF
FA FC FA FC FA FC FA FC FA FC F4 FA F8 04 00 F8
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
7C 83 C6 39 DE 39 DE 39 DE 39 DE 39 7C 83 01 FF
DB E7 FB C7 DB E7 FB E7 FB E7 FB E7 FD C3 C1 FF
7C 83 C6 39 1E F9 BC C3 60 9F DE 39 FE 01 00 FF
7C 83 C6 39 3E F9 FC C3 C6 F9 FE 39 7C 83 00 FF
FD E3 FD C3 ED 93 CD 33 FE 01 0C F3 FE E1 E0 FF
FE 01 C0 3F FC 03 06 F9 FE F9 FE 39 7C 83 00 FF
7C 83 C6 39 D8 3F FC 03 C6 39 DE 39 7C 83 00 FF
FE 01 C6 39 2C F3 D9 E7 F7 CF F7 CF FB 87 83 FF
7C 83 C6 39 DE 39 7C 83 C6 39 DE 39 7C 83 00 FF
7C 83 C6 39 DE 39 7E 81 06 F9 DE 39 7C 83 01 FF
FF FF F7 CF F7 CF C7 FF F7 CF F7 CF C7 FF FF FF
FF FF FF FF F7 CF C7 FF F7 CF F7 CF D7 EF E7 DF
F7 CF F7 CF F7 CF F7 CF C7 FF F7 CF F7 CF C7 FF
F7 CF F7 CF D7 EF E7 DF CF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF F7 CF F7 CF D7 EF E7 DF
79 87 8D 73 3D F3 D9 E7 F3 CF C7 FF F7 CF C7 FF
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
FF C7 FB C7 AB D7 ED 93 7D 83 C6 39 DE 39 18 FF
FD 03 66 99 EE 99 FC 83 E6 99 EE 99 FC 03 00 FF
FD 83 C6 39 D8 3F DF 3F DF 3F DE 39 7C 83 81 FF
FF 03 67 99 EE 99 EE 99 EE 99 EE 99 FD 03 03 FF
FE 01 62 9D EC 9F FB 87 E3 9F EE 9D FE 01 00 FF
FE 01 62 9D EC 9F FB 87 E3 9F EF 9F F7 0F 07 FF
FD 83 C6 39 D8 3F DE 31 D6 39 DE 39 7D 83 83 FF
DE 39 DE 39 DE 39 FE 01 C6 39 DE 39 DE 39 18 FF
FD C3 D9 E7 FB E7 FB E7 FB E7 FB E7 FD C3 C1 FF
FE E1 EC F3 FD F3 FD F3 FD 33 FD 33 7B 87 87 FF
E6 19 6D 93 FB 87 F7 8F FB 87 ED 93 E6 19 00 FF
F7 0F 67 9F EF 9F EF 9F EF 9F EE 9D FE 01 00 FF
C6 39 EE 11 FE 01 D6 29 D6 29 C6 39 DE 39 18 FF
EE 19 EE 19 F6 09 DE 21 CE 31 CE 31 D6 39 10 FF
FD 83 C6 39 DE 39 DE 39 DE 39 D6 39 7D 83 83 FF
FC 03 66 99 EE 99 FC 83 E0 9F EF 9F F7 0F 07 FF
FD 83 C6 39 DE 39 DE 39 D6 29 CE 31 FD 83 86 F9
FC 03 66 99 EE 99 FC 83 E6 99 EE 99 EE 19 08 FF
7D 83 C6 39 DC 3F 7C 83 06 F9 DE 39 7C 83 80 FF
FE 01 B2 4D 30 CF F3 CF F3 CF F3 CF F9 87 81 FF
EE 19 6E 99 EE 99 EE 99 EE 99 EE 99 BC C3 80 FF
DE 39 DE 39 5C BB 6D 93 ED 93 A9 D7 BB C7 C3 FF
D6 29 D6 29 D6 29 FE 01 EE 11 C6 39 D6 39 38 FF
DE 39 C6 39 6D 93 B9 C7 ED 93 C6 39 D6 39 18 FF
DE 39 C6 39 6D 93 B9 C7 F3 CF F3 CF F9 87 81 FF
FE 01 8C 73 39 E7 F3 CF E7 9F CE 3D FE 01 00 FF
FB E7 F3 CF F7 CF F7 CF F7 CF F7 CF DB E7 C3 FF
FF 3F 7F 9F BF CF DF E7 EF F3 F6 F9 FA FD FC FF
F3 CF DB E7 FB E7 FB E7 FB E7 FB E7 F3 CF C3 FF
FF FF FF FF FF FF FF FF FF FF FB E7 FB E7 E3 FF
FF FF FF FF FF FF FB 87 FB 87 83 FF FF FF FF FF


compressed gfx $84:B727 from rom:
Code Select

00 04 FD FF 00 C0 3F 00 60 1F 5F BF F5 7F 15 60
FF FE CF F8 00 04 F8 07 F2 FC FA 35 60 16 70 16
30 36 70 3A B0 FF 5F BF 2F DF 1F 60 00 3F F8 00
A0 FE 0F 56 70 F4 FA F8 04 00 01 F8 00 D0 9F F0
B1 F0 C3 F0 D5 F0 E7 F0 00 30 DF 7C 83 C6 39 DE
03 41 7C 83 3F 01 FF DB E7 FB C7 10 01 15 21 F7
FD C3 C1 FF 20 1E F9 BC C3 7F 60 9F DE 39 FE 01
00 FF 20 7F 3E F9 FC C3 C6 F9 FE 0B 01 FF 00 FF
FD E3 FD C3 ED 93 FF CD 33 FE 01 0C F3 FE E1 FF
E0 FF FE 01 C0 3F FC 03 27 06 F9 FE 39 41 00 11
D8 53 01 02 11 FE 3C 11 FE 01 C6 39 2C F3 D9 FF
E7 F7 CF F7 CF FB 87 83 F8 FF 40 80 51 2E 31 DE
39 7E 81 06 2D F9 0A 31 FF FF 78 11 C7 A1 41 00
30 1E A4 51 D7 EF E7 DF 78 11 A2 91 B8 51 F9 CF
00 C0 B8 51 79 87 8D 73 3D CA 75 01 F3 A5 21 C7
20 00 F2 CF C7 FB BF C7 AB D7 ED 93 7D 01 21 18
FF FF FD 03 66 99 EE 99 FC 4B 83 E6 23 12 03 3E
01 61 21 DF 35 02 3E 0A 11 81 FF FF 03 67 23 02
44 32 F7 FD 03 03 4F 01 62 9D EC 9F 3F FB 87 E3
9F EE 9D 2C 11 50 72 DF EF 9F F7 0F 07 2F 42 DE
31 3D D6 03 01 7D 83 83 FF 04 31 70 11 CC 04 11
1E 02 C3 D9 15 41 1A 31 FE E1 F7 EC F3 FD A3 12
33 FD 33 7B FF 87 87 FF E6 19 6D 93 FB FF 87 F7
8F FB 87 ED 93 E6 3F 19 00 FF F7 0F 67 69 02 C4
12 FE 5A 32 C6 39 EE 11 FE 01 D6 F7 29 D6 29 1A
32 EE 19 EE 19 7F F6 09 DE 21 CE 31 CE 77 02 A9
10 2F 22 04 31 D6 7B 22 FC 21 42 E0 FC 69 82 F6
22 29 CE 31 FD 83 86 79 F9 00 53 28 12 EE 19 08
FF 18 12 AF DC 3F 7C 83 98 31 80 4F 01 B2 EF 4D
30 CF F3 45 23 F9 87 81 BA DF 02 6E 43 62 BC C3
80 7F 22 5C FF BB 6D 93 ED 93 A9 D7 BB F7 C7 C3
FF D6 12 D6 29 FE 01 D7 EE 11 C6 F9 02 38 7F 02
C6 39 BF 6D 93 B9 C7 ED 93 7A 13 18 7C 7F 63 48
53 FE 01 8C 73 39 F7 01 2F E7 9F CE 3D 2C 11 FB
F7 01 C0 51 F7 DB E7 C3 0E 00 7F 9F BF CF FF DF
E7 EF F3 F6 F9 FA FD 67 FC FF F3 BB 03 94 52 F3
CF BE 03 14 00 60 16 11 E3 E3 53 87 7C 11 79 10


compressed gfx $84:B727 from tool that I posted below:
http://www.mediafire.com/file/x3i0nc0y92pgedd/BlackthorneCompressorTest2.rar/file
Code Select

00 04 FD FF 00 C0 3F 00 60 1F 5F BF F5 7F 15 60
FF FE CF F8 00 04 F8 07 F2 FC FA 35 60 16 70 16
30 36 70 3A B0 FF 5F BF 2F DF 1F 60 00 3F F8 00
A0 FE 0F 36 70 F4 FA F8 04 00 01 F8 00 D0 9F F0
B1 F0 C3 F0 D5 F0 E7 F0 00 30 DF 7C 83 C6 39 DE
03 41 7C 83 3F 01 FF DB E7 FB C7 10 01 15 21 F7
FD C3 C1 FF 20 1E F9 BC C3 7F 60 9F DE 39 FE 01
00 FF 20 7F 3E F9 FC C3 C6 F9 FE 0B 01 FF 00 FF
FD E3 FD C3 ED 93 FF CD 33 FE 01 0C F3 FE E1 FF
E0 FF FE 01 C0 3F FC 03 27 06 F9 FE 39 41 00 11
D8 53 01 02 11 FE 3C 11 FE 01 C6 39 2C F3 D9 FF
E7 F7 CF F7 CF FB 87 83 F8 FF 40 80 51 2E 31 DE
39 7E 81 06 2D F9 0A 31 FF FF 78 11 C7 A1 41 00
30 1E A4 51 D7 EF E7 DF 78 11 A2 91 B8 51 F9 CF
00 C0 B8 51 79 87 8D 73 3D CA 75 01 F3 A5 21 C7
20 00 F2 CF C7 FB BF C7 AB D7 ED 93 7D 01 21 18
FF FF FD 03 66 99 EE 99 FC 4B 83 E6 23 12 03 3E
01 61 21 DF 35 02 3E 0A 11 81 FF FF 03 67 23 02
44 32 F7 FD 03 03 4F 01 62 9D EC 9F 3F FB 87 E3
9F EE 9D 2C 11 50 72 DF EF 9F F7 0F 07 2F 42 DE
31 3D D6 03 01 7D 83 83 FF 04 31 70 11 CC 04 11
1E 02 C3 D9 15 41 1A 31 FE E1 F7 EC F3 FD A3 12
33 FD 33 7B FF 87 87 FF E6 19 6D 93 FB FF 87 F7
8F FB 87 ED 93 E6 3F 19 00 FF F7 0F 67 69 02 C4
12 FE 5A 32 C6 39 EE 11 FE 01 D6 F7 29 D6 29 1A
32 EE 19 EE 19 7F F6 09 DE 21 CE 31 CE 77 02 A9
10 2F 22 04 31 D6 7B 22 FC 21 42 E0 FC 69 82 F6
22 29 CE 31 FD 83 86 79 F9 00 53 28 12 EE 19 08
FF 18 12 AF DC 3F 7C 83 98 31 80 4F 01 B2 EF 4D
30 CF F3 45 23 F9 87 81 BA DF 02 6E 43 62 BC C3
80 7F 22 5C FF BB 6D 93 ED 93 A9 D7 BB F7 C7 C3
FF D6 12 D6 29 FE 01 D7 EE 11 C6 F9 02 38 7F 02
C6 39 BF 6D 93 B9 C7 ED 93 7A 13 18 7C 7F 63 48
53 FE 01 8C 73 39 F7 01 2F E7 9F CE 3D 2C 11 FB
F7 01 C0 51 F7 DB E7 C3 0E 00 7F 9F BF CF FF DF
E7 EF F3 F6 F9 FA FD 67 FC FF F3 BB 03 94 52 F3
CF BE 03 14 00 60 16 11 E3 E3 53 87 7C 11 00 10


In the compressed gfx file that my tool produced I found 2 sliding windows that have different locations than
the original compressed gfx.
1. $0033 in rom = 56 70, $0033 in my tool = 36 70

Both have the same size and same byte pattern but different locations
FA FC FA FC FA FC FA FC FA FC
in rom 7e:4056-7e:405f
in tool 7e:4036- 7e:403f
there is a total of 4 or 5 matches of this group of bytes


2. $024e in rom = 79 10, in my tool $024e = 00 10

Both have the same size and same byte pattern but different locations
FF FF FF FF
in rom 7e:4079-7e:407c
in tool 7e:4000- 7e:4003
there are a lot of matches

I know the sliding windows can start going forward or backwards and if the same size of matching bytes
are found multiple time it could ether go with the 1st time that pair is found or the last time that
pair was found. These 2 windows seem to be somewhere in between. The original compressor could have been
programed to use random locations for the patterns that are the same bytes of the same size but if that
was the case I would think more of the sliding window locations would be different than just 2 of them.
There has to be some sort of pattern that I haven't found yet. I have yet to fully look at the compressed
gfx that are > 0x10000 in size so that might help find the last piece of the puzzle. I'm not sure that
I can spend much more time on this because I have a lot going on right now but I can do a little more next
week.

Test out the tool and let me know if it is compressing the gfx size correctly and if the gfx is decompressed
correctly in rom. The tool still does not compress files larger than 0x10000 but that will be updated when I get
more time.
October 19, 2020, 07:13:49 PM - (Auto Merged - Double Posts are not allowed before 7 days.)

I forgot to mention for the 2 sliding windows that have different locations than
the original compressed gfx I did find something that could be the missing link but
it might just be a coincidence.

For:
1. $0033 in rom = 56 70, $0033 in my tool = 36 70

Both have the same size and same byte pattern but different locations
FA FC FA FC FA FC FA FC FA FC

The pattern for mine is the 1st time it occurs and for the pattern in the
compressed gfx from the rom it is the 5th time it occurs. Well the compression byte
is 0xf8 and the bits are 1111 1000. Bit 2 is the one used for this window and it has
a bit value of 4. Is it a coincidence, idk?

For:
2. $024e in rom = 79 10, in my tool $024e = 00 10

Both have the same size and same byte pattern but different locations
FF FF FF FF

The pattern for mine is the 1st time it occurs and for the pattern in the
compressed gfx from the rom it is the 33rd time it occurs. Well the compression byte
is 0x14 and the bits are 00010100. Bit 5 is the one used for this window and it has
a bit value of 32. Is it a coincidence, idk?

I'm probably over thinking and these two things are just a coincidence but more research
definitely needs to be done. At least it produces the same compression size.

RodMerida

#12
October 24, 2020, 09:17:45 AM Last Edit: December 05, 2020, 11:12:41 AM by RodMerida
Thank you for the technical information, it will be very useful, even though I don't think I may program something that compresses to this format, or uncompresses, without errors.

Do you have a clue about if the MS-DOS version of the game uses the same kind of compression format?

slidelljohn

#13
October 27, 2020, 06:11:30 PM
I don't know if the dos version uses the same compression.
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