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ASM Sonic the Fighters - Disassembly (and discoveries from it)

Discussion in 'Engineering & Reverse Engineering' started by biggestsonicfan, Jun 1, 2020.

  1. biggestsonicfan

    biggestsonicfan

    Model2wannaB Tech Member
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    ALWAYS Sonic the Fighters
    It's about time I finally released what I have: The Sonic the Fighters Disassembly Repo!

    It's in it's infancy, and there are a few things that should be taken into consideration:
    1. This build is not close to being build-able. Once I am able to compile a valid Model2b binary, I can then begin comparing the binary to the source ROM and made changes accordingly.
    2. To reduce the size of the disassembly, the memory segment of the IDA file has been stripped, however the labels remain. This is why you will see some labels with no references. Bare with me until I figure out a solution for this.
    3. There are errors. Probably lots of them. Things like loc_FFF8+7 should be 0xFFFF, I just haven't fixed them all yet.
    4. I am new to assembly, and do not fully comprehend how to use include or macros yet.
    5. HELP WANTED! I don't know what people can do, submit issues for what you find or even pull requests would be nice though to fix things. Keep in mind I have to make the changes in IDA Pro first, then re-export to an ASM file, so any submitted issues or pull requests will take time to fix.
    I've spent probably close to two years on this now, and recently trying to reassemble the ROM helped fix a lot of things I wasn't aware of. I will try to get this repo 1:1 with the original ROM source, but I can't promise any time frame.

    Enjoy!
     
  2. Lostgame

    Lostgame

    producer/turnablist. homebrew dev. cosplayer. Oldbie
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    Great work. Any progress is progress, thanks for sharing; keep it up.
     
  3. biggestsonicfan

    biggestsonicfan

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    ALWAYS Sonic the Fighters
    Thank you! I will! I also just this morning successfully assembled and linked a ROM binary from the disassembly and hope to upload instructions soon to the git!
     
  4. biggestsonicfan

    biggestsonicfan

    Model2wannaB Tech Member
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    ALWAYS Sonic the Fighters
    Small update, the binary the disassembly now is bit-identical to the binary for the Sonic the Fighters ROM. It's build-able, but you will still need to split the binary in two word-interleaved files to load it into the emulator. I have a tool I made to do that but it needs further polish before release. For now, we can just celebrate the first bit-perfect Model2 disassembly to exist!
     
  5. TheInvisibleSun

    TheInvisibleSun

    OVER THE TOP TECHNO-BLAST Member
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    The Water
    Awesome to finally see a disassembly! How far are we from things like, model imports and whatnot (if this is a ridiculous question, pardon my ignorance)? It'd be kind of fun to see VF Kids models in this game or something like that.
     
  6. biggestsonicfan

    biggestsonicfan

    Model2wannaB Tech Member
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    ALWAYS Sonic the Fighters
    Quite a ways away, unfortunately. I am fairly sure the models are baked into the "main data" EPROMs, and it will take quite a bit of research to first understand the model format, more research to translate it into something that can be viewable in a computer space, and then reversing that process. @RyogaMasaki and I plan on taking a close look at how models are drawn in debug mode, but that's a ways off when his schedule clears up. But based on how I see models work and how tightly everything fits together in this game, I would say importing is going to be much further off than exporting models.
     
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  7. biggestsonicfan

    biggestsonicfan

    Model2wannaB Tech Member
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    ALWAYS Sonic the Fighters
    A minor update:

    The rom_code1.asm and rom_code1(labels).asm have been merged into rom_code1.asm. The reason they were split were so labels were human readable in rom_code1(labels).asm [eg. "debug_flag], and rom_code1.asm was able to be properly assembled without these labels [eg. 0x508000 instead of "debug_flag"]. But now, by default, there is an "include.S" file that tells the assembler that these labels should have the hex values when assembled. Et, Volia, two become one!
     
  8. Aesculapius Piranha

    Aesculapius Piranha

    つづく Oldbie
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    Diva
    To me the cool thing about this is more just hey we have an actual look at the work that went into Virtua Fighter games. I mean, in a weird way STF was itself kind of a Sonic Themed fan mod by AM2 that was based on work that went into the VF series. Want to understand the games modern 3D fighters are based off of? Here you go!
     
  9. Lostgame

    Lostgame

    producer/turnablist. homebrew dev. cosplayer. Oldbie
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    The O.I.C.
    Oh, wow; that’s *serious* progress! Awesome!
     
  10. biggestsonicfan

    biggestsonicfan

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    ALWAYS Sonic the Fighters
    I dunno if this belongs in this thread or the other thread but I think I'm just going to post this in here:

    Upon closer examination of the disassembly, I've mislabeled a few things, and in the process, identified 3 unreferenced debug menu entries. All crash upon trying to hack them into the main debug menu.

    Entry 1: Not entirely sure what this one would have done. Loads Player1's parts.
    sfight025.png
    Entry 2: A coin menu. Looks like this may have been used for early bookkeeping manipulation without playing the game. Keeps track of credits, which shoot they entered, and service buttons.
    sfight026.png
    Entry 3: A scale menu? Lists each playable (without modification) character including grey-scale characters and each one has a float value assigned to it. The float values are all defined as 1.0, but I assume this menu allowed you to alter these float values. The floats when manipulated via hacking don't seem to have any affects.
    sfight024.png

    I'm bashing away trying to document as much as I can before the next git refresh, so please look forward to it.

    EDIT: Pictures.
     
    Last edited: Aug 25, 2020
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  11. biggestsonicfan

    biggestsonicfan

    Model2wannaB Tech Member
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    ALWAYS Sonic the Fighters
    A new model of Eggman has been uncovered! Completely unreferenced data. He is larger than the Eggman seen in the beginning intro of the game, but smaller than the other unused "Eggmanb" Big Eggman.

    sfight031.png
    Eggman vs New Middle Sized Eggman

    sfight032.png
    Big Eggman vs New Middle Sized Eggman

    There is more Eggman in this game than there is Sonic...
     
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  12. biggestsonicfan

    biggestsonicfan

    Model2wannaB Tech Member
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    ALWAYS Sonic the Fighters
    All 4475 model objects from the game have now been added to the repo!
     
  13. ValleyBell

    ValleyBell

    Tech Member
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    researching PC-98/X68000 sound drivers
    I guess I should contribute what I researched regarding sound stuff:

    At first, we have a disassembly of the sound driver: http://vgmrips.net/misc/schamp_SoundDriver_disasm.7z

    I made this in 2013 and the labels are far from complete. There is a small list of sound RAM offsets.

    The general collection of pointer lists begins at 0x008000 and is 0x2C bytes long (11 different lists).
    It has pointers to the following tables:
    - 0x008000: Sample Table -> 0x00A3FC
    - 0x008004: Instrument Table -> 0x00C9E4
    - 0x00800C: Music Track Initialization Data -> 0x0080B2
    - 0x008010: SFX Track Initialization Data -> 0x008080
    - 0x00801C: Music/SFX group lists -> 0x00E2E2
    - 0x008028: note velocity lookup table -> 0x00FB04

    Following such a pointer almost always leads to a 16-bit Big Endian word that tells you either the size or the number of entries in the table.
    ... except that it ALWAYS denotes (n-1).

    Also note that the ROM is mapped to address 0x600000..0x7FFFFF of the 68000 address space. Thus all addresses have 0x600000 added to them.
    I list the actual ROM offsets here, not the CPU addresses.

    Examples:
    - Sample Table 0x00A3FC: The first word reads "259F", which means that the next 0x25A0 bytes are sample data.
    - Instrument Table 0x00C9E4: The first word reads "0052". It is followed by 0x53 pointers to instrument definition data. Those are relative to 0x00C9E4.
    - music/SFX group lists 0x00E2E2: The first word reads "0004". It is followed by 5 (relative) pointers. (1 music + 4 SFX groups)
    - music pointer list 0x00E2EE. The first word read "0018". There are 0x19 songs. Pointers are relative to 0x00E2E2. (i.e. music/SFX group list)
    The first pointer ("0448") points to 0x00E2E2 + 0x0448 = 0x00E72A


    The music format itself consists of a list of "chunks"/"patterns" with special commands (track initialization, loops) in between.
    The pattern data itself is MIDI-based, with a slightly optimized notation that allows you to omit delays.

    I'll just list a small example of how it works with song 0 (offset 0x00E72A):

    Code (Text):
    1. 00E72E   00: type identifier  (00 = music, 80..FF = SFX, 01..7F = special)
    2. 00E72F   00 00 00: ignored
    3. 00E732   80 A0 00 02: enqueue MIDI command A0 00 02 (reset all channels)
    4. 00E736   80 A0 07 00: enqueue MIDI command A0 07 00 (load instrument initialization number 0x00)
    5. 00E73A   0060EB16: play segment at 0x00EB16
    6. loop:
    7. 00E73E   00610000: play segment at 0x010000
    8. 00E742   00611300: play segment at 0x011300
    9. 00E746   00611E00: play segment at 0x011E00
    10. 00E74A   00612800: play segment at 0x012800
    11. 00E74E   00613B00: play segment at 0x013B00
    12. 00E752   FFFFFFF1 0060E73E: jump to position 0x00E73E (loop)
    13.  
    14. A value of FFFFFFFF in the pattern list denotes the end of the song.

    A pattern segment consists of MIDI commands, which are written to a global queue when they are to be played. (same queue as "enqueue MIDI command" in the pattern list)

    Code (Text):
    1.  
    2. MIDI commands supported by MIDI segment parser + global MIDI command parser:
    3. 8c nn - Note Off (channel c), note nn (internally converted to 8c nn 7F, but the Off-Velocity is ignored anyway)
    4. 9c nn vv - Note On (channel c), note nn, velocity vv (vv == 0 -> Note Off)
    5. Ac xx dd - execute special command xx with parameter dd (I think the channel is ignored? not sure)
    6. Bc ii dd - Control Change (channel c), controller ID ii, data dd
    7.    The sound driver supports:
    8.        01 - Modulation
    9.        02
    10.        07 - Channel Volume
    11.        0A - Panorama
    12.        11..19
    13.        29..2B
    14.        30..35
    15.        40..4C
    16.        50
    17. Cc ii - Instrument Change (channel c), set instrument to ii
    18. Ec ll mm - Pitch Bend (channel c), value mmll (mm and ll is 7 bits each, just like normal MIDI)
    19.  
    20. Commands 00..7F/D0..DF/F0..FF are ignored.
    21.  
    22. The MIDI segment parser also supports these additional commands:
    23. Dc nn - Channel Aftertouch (channel c) (copied into global MIDI command queue, but has no effect there)
    24. F0 [dd dd ...] F7 - SysEx (the driver skips everything until/including the next F7 it finds)
    25. F7 ll [dd dd ...] - SysEx Continuation (the driver skips ll bytes from the first dd on)
    26. FF 2F xx - Segment End
    27. FF ii ll [dd dd ...] - Meta Event (the driver skips ll bytes from the first dd on)
    28.  
    29. The "running status" trick is supported by the MIDI segment parser.
    30.  
    In the MIDI segments, they use a neat trick to save some bytes:
    When the last parameter byte has bit 7 set (results in value 80..FF), then the delay byte is omitted and the next event follows immediately.

    Example:
    Code (Text):
    1. 0100D0   99 56 46   Note On, ch 9, note 0x56, velocity 0x46
    2. 0100D3   2E       delay: 0x2E ticks
    3. 0100D4   86 45       Note Off, ch 6, note 0x45
    4. 0100D6   22       delay: 0x22 ticks
    5. 0100D7   B6 0A 7F   Control Change, ch 6, Pan, value 0x7F
    6. 0100DA   0A       delay: 0x0A ticks
    7. 0100DB   0A 76       (Control Change, ch 6), Pan, value 0x76
    8. 0100DD   03       delay: 0x03 ticks
    9. 0100DE   89 D6       Note Off, ch 9, note 0x56, no delay
    10. 0100E0   99 51 C6   Note On, ch 9, note 0x51, velocity 0x46, no delay
    11. 0100E3   58 46       (Note On, ch 9), note 0x58, velocity 0x46
    12. 0100E5   00       delay: 0 ticks
    13. 0100E6   96 39 41   Note On, ch 6, note 0x39, velocity 0x41
    14. 0100E9   2E        delay: 0x2E ticks
    15. 0100EA   88 CC       Note Off, ch 8, note 0x4C, no delay
    16. 0100EC   88 45       Note Off, ch 8, note 0x45
    17. 0100EE   00       delay: 0 ticks

    I wrote a converter to convert songs from Sonic The Fighters to usual MIDI + SF2 soundfonts.
    You can find the source code here: M2MidiDec.c


    And now something I researched today, due to a feature request for M2MidiDec:

    The sound test has all names and commands listed.
    The offset list that references all items from the sound test is located at 0x0DC400 in the program ROM.
    The items themselves begin at offset 0x09A270. They consist of a 4-byte MIDI command (stored in Little Endian, the highest byte is ignored), followed by a null-terminated string.

    Here is the full list:
    Code (Text):
    1. No.   command   name
    2. 0   A00001   sd_ALL_CLEAR
    3. 1   AE1100   sd_jump_1
    4. 2   AE1101   sd_jump_2
    5. 3   AE1102   sd_ring_2
    6. 4   AE1103   sd_spin_1
    7. 5   AE1104   sd_spin_2
    8. 6   AE1105   sd_plane_1
    9. 7   AE1106   sd_plane_3
    10. 8   AE1107   sd_plane_4
    11. 9   AE1400   sd_plane_4_off
    12. 10   AE1108   sd_fall_2
    13. 11   AE1109   sd_fall_6
    14. 12   AE110A   sd_fall_9
    15. 13   AE110B   sd_kick_kara_1
    16. 14   AE110C   sd_kick_kara_2
    17. 15   AE110D   sd_punch_kara_1
    18. 16   AE110E   sd_punch_kara_2
    19. 17   AE110F   sd_punch_a
    20. 18   AE1110   sd_punch_b
    21. 19   AE1111   sd_punch_c
    22. 20   AE1112   sd_punch_d
    23. 21   AE1113   sd_punch_e
    24. 22   AE1114   sd_punch_f
    25. 23   AE1115   sd_punch_g
    26. 24   AE1116   sd_punch_h
    27. 25   AE1117   sd_punch_j
    28. 26   AE1118   sd_punch_k
    29. 27   AE1119   sd_punch_m
    30. 28   AE111A   sd_punch_n
    31. 29   AE111B   sd_punch_o
    32. 30   AE111C   sd_punch_p
    33. 31   AE111D   sd_punch_q
    34. 32   AE111E   sd_punch_r
    35. 33   AE111F   sd_punch_s
    36. 34   AE1120   sd_rope_1
    37. 35   AE1121   sd_rope_2
    38. 36   AE1122   sd_rope_2a
    39. 37   AE1123   sd_rope_2b
    40. 38   AE1124   sd_plane_2a
    41. 39   AE1401   sd_plane_2a_off
    42. 40   AE1125   sd_plane_2b
    43. 41   AE1402   sd_plane_2b_off
    44. 42   AE1126   sd_rope_3
    45. 43   AE1127   sd_rope_4
    46. 44   AE1128   sd_up_2
    47. 45   AE1129   sd_up_3
    48. 46   AE112A   sd_cane_2c
    49. 47   AE112B   sd_cane_2cc
    50. 48   AE112C   sd_cane_2d
    51. 49   AE112D   sd_cane_2dd
    52. 50   AE112E   sd_cork_1a
    53. 51   AE112F   sd_cork_1b
    54. 52   AE1130   sd_cork_6a
    55. 53   AE1131   sd_cork_6b
    56. 54   AE1132   sd_cork_6c
    57. 55   AE1133   sd_fence_1
    58. 56   AE1134   sd_fence_2
    59. 57   AE1135   sd_fence_3
    60. 58   AE1136   sd_g_punch_1
    61. 59   AE1137   sd_g_punch_2
    62. 60   AE1138   sd_land_1
    63. 61   AE1139   sd_wall_1
    64. 62   AE113A   sd_ufo_6a
    65. 63   AE1403   sd_ufo_6a_off
    66. 64   AE113B   sd_ufo_6b
    67. 65   AE1404   sd_ufo_6b_off
    68. 66   AE113C   sd_ufo_esc_1
    69. 67   AE113D   sd_computer_1
    70. 68   AE1405   sd_computer_1_off
    71. 69   AE113E   sd_water_4c
    72. 70   AE1406   sd_water_4c_off
    73. 71   AE113F   sd_plane_2
    74. 72   AE133D   sd_bomb_1
    75. 73   AE133E   sd_bomb_2
    76. 74   AE1142   sd_gong_1
    77. 75   AE1143   sd_gong_2
    78. 76   AE1144   sd_guard_1
    79. 77   AE1145   sd_gum_2
    80. 78   AE1146   sd_gum_2a
    81. 79   AE1147   sd_gum_2c
    82. 80   AE1148   sd_gum_2d
    83. 81   AE1149   sd_gum_2e
    84. 82   AE114A   sd_pico_2a
    85. 83   AE114B   sd_pico_2b
    86. 84   AE114C   sd_pico_2c
    87. 85   AE114D   sd_pico_2d
    88. 86   AE114E   sd_pico_2e
    89. 87   AE114F   sd_pico_2f
    90. 88   AE1150   sd_computer_2
    91. 89   AE1407   sd_computer_2_off
    92. 90   AE1151   sd_pinball_2
    93. 91   AE1152   sd_pinball_6
    94. 92   AE1153   sd_pinball_a
    95. 93   AE1154   sd_pinball_b
    96. 94   AE1155   sd_pinball_c
    97. 95   AE1156   sd_pinball_d
    98. 96   AE1157   sd_pinball_e
    99. 97   AE1158   sd_pinball_f
    100. 98   AE1159   sd_pinball_g
    101. 99   AE115A   sd_pinball_h
    102. 100   AE115B   sd_pinball_j
    103. 101   AE115C   sd_pinball_k
    104. 102   AE115D   sd_pinball_m
    105. 103   AE115E   sd_prop_1
    106. 104   AE1408   sd_prop_1_off
    107. 105   AE115F   sd_prop_11
    108. 106   AE1409   sd_prop_11_off
    109. 107   AE1160   sd_prop_2
    110. 108   AE140A   sd_prop_2_off
    111. 109   AE1161   sd_prop_22
    112. 110   AE140B   sd_prop_22_off
    113. 111   AE1162   sd_prop_3
    114. 112   AE140C   sd_prop_3_off
    115. 113   AE1163   sd_prop_33
    116. 114   AE140D   sd_prop_33_off
    117. 115   AE1164   sd_takeko_1
    118. 116   AE140E   sd_takeko_1_off
    119. 117   AE1165   sd_takeko_2
    120. 118   AE140F   sd_takeko_2_off
    121. 119   AE1166   sd_takeko_3
    122. 120   AE1410   sd_takeko_3_off
    123. 121   AE1167   sd_takeko_5
    124. 122   AE1411   sd_takeko_5_off
    125. 123   AE1168   sd_wall_hit_1
    126. 124   AE1169   sd_wall_hit_2
    127. 125   AE116A   sd_wall_hit_3
    128. 126   AE116B   sd_wall_hit_4
    129. 127   AE116C   sd_wall_hit_5
    130. 128   AE1309   sd_waterfall_1
    131. 129   AE1412   sd_waterfall_1_off
    132. 130   AE116E   sd_computer_3
    133. 131   AE1413   sd_computer_3_off
    134. 132   AE116F   sd_xylo_1
    135. 133   AE1170   sd_xylo_2
    136. 134   AE1171   sd_xylo_mix1_22
    137. 135   AE1172   sd_swing_c
    138. 136   AE1173   sd_swing_d
    139. 137   AE1174   sd_swing_e
    140. 138   AE1175   sd_swing_f
    141. 139   AE1176   sd_swing_g
    142. 140   AE1177   sd_swing_h
    143. 141   AE1178   sd_clash_1
    144. 142   AE1179   sd_knock_2
    145. 143   AE117A   sd_knock_3
    146. 144   AE117B   sd_knock_9
    147. 145   AE117C   sd_pecha_2
    148. 146   AE117D   sd_pecha_2a
    149. 147   AE1200   sd_aou01
    150. 148   AE1201   sd_aou02
    151. 149   AE1202   sd_auch01
    152. 150   AE1203   sd_auch02
    153. 151   AE1208   sd_kyuu01
    154. 152   AE1216   sd_scream01
    155. 153   AE1217   sd_scream02
    156. 154   AE121C   sd_WB01_13_03
    157. 155   AE121D   sd_WB01_18_01
    158. 156   AE121E   sd_WB01_18_02
    159. 157   AE121F   sd_WB01_25_01
    160. 158   AE1220   sd_WB01_26_01
    161. 159   AE1221   sd_WB01_26_02
    162. 160   AE1222   sd_WB01_27_01
    163. 161   AE1223   sd_WB01_27_02
    164. 162   AE1224   sd_WB01_28_01
    165. 163   AE1225   sd_WB01_28_02
    166. 164   AE1226   sd_WB01_77_01
    167. 165   AE1227   sd_WB01_77_02
    168. 166   AE1228   sd_WB02_01_00
    169. 167   AE1229   sd_WB02_02_02
    170. 168   AE122A   sd_WB02_15_01
    171. 169   AE122B   sd_WB02_19_02
    172. 170   AE122C   sd_WB02_24_01
    173. 171   AE122D   sd_WB02_24_03
    174. 172   AE122E   sd_WB02_25_02
    175. 173   AE122F   sd_WB02_29_05
    176. 174   AE1230   sd_WB02_33_01
    177. 175   AE1231   sd_WB02_67_01
    178. 176   AE1232   sd_WB02_70_03
    179. 177   AE1233   sd_WB02_71_01
    180. 178   AE1234   sd_WB03_72_01
    181. 179   AE1235   sd_WB03_72_02
    182. 180   AE1236   sd_WB04_62_01
    183. 181   AE1237   sd_WB04_62_02
    184. 182   AE1238   sd_WB04_62_05
    185. 183   AE1239   sd_WB04_63_01
    186. 184   AE123A   sd_WB04_64_01
    187. 185   AE123B   sd_WB04_81_01
    188. 186   AE123C   sd_WB04_82_04
    189. 187   AE123D   sd_WB04_83_04
    190. 188   AE123E   sd_WB04_90_03
    191. 189   AE123F   sd_WB04_91_01
    192. 190   AE1240   sd_WB04_91_02
    193. 191   AE1241   sd_WB04_92_01
    194. 192   AE1242   sd_WB04_92_02
    195. 193   AE1243   sd_WB04_92_03
    196. 194   AE1244   sd_WB05_32_01
    197. 195   AE1414   sd_WB05_32_01_off
    198. 196   AE1245   sd_WB05_51_03
    199. 197   AE1246   sd_WB99_01
    200. 198   AE1247   sd_WB99_02
    201. 199   AE1248   sd_WB99_03
    202. 200   AE1249   sd_US02_75_02
    203. 201   AE124A   sd_US02_79_01
    204. 202   AE124B   sd_US02_79_02
    205. 203   AE124C   sd_US02_79_05
    206. 204   AE124D   sd_US02_79_3
    207. 205   AE124E   sd_US03_06_01
    208. 206   AE1415   sd_US03_06_01_off
    209. 207   AE124F   sd_US03_59_04
    210. 208   AE1250   sd_US04_11_01
    211. 209   AE1251   sd_US04_11_02
    212. 210   AE1252   sd_US04_12_01
    213. 211   AE1253   sd_US04_12_02
    214. 212   AE1254   sd_US04_14_01
    215. 213   AE1416   sd_US04_14_01_off
    216. 214   AE1255   sd_US04_15_01
    217. 215   AE1417   sd_US04_15_01_off
    218. 216   AE1256   sd_US04_49_05
    219. 217   AE1300   sd_bird_2
    220. 218   AE1302   sd_gong_4
    221. 219   AE1309   sd_waterfall_1
    222. 220   AE130A   sd_waterfall_2
    223. 221   AE130B   sd_ring_5a
    224. 222   AE130C   sd_ring_5b
    225. 223   AE130D   sd_ring_5c
    226. 224   AE130E   sd_ring_5d
    227. 225   AE130F   sd_ring_5e
    228. 226   AE1310   sd_ring_5f
    229. 227   AE1311   sd_ring_5g
    230. 228   AE1312   sd_ring_5h
    231. 229   AE1313   sd_ring_5i
    232. 230   AE1314   sd_ring_5j
    233. 231   AE1315   sd_ring_5k
    234. 232   AE1316   sd_ring_5m
    235. 233   AE1317   sd_ring_5n
    236. 234   AE1318   sd_bound_1a
    237. 235   AE1319   sd_hit_1a
    238. 236   AE131A   sd_hit_1b
    239. 237   AE131B   sd_hit_1c
    240. 238   AE131C   sd_hit_1d
    241. 239   AE131D   sd_hit_1e
    242. 240   AE131E   sd_splash_2
    243. 241   AE131F   sd_splash_3
    244. 242   AE1320   sd_splash_4
    245. 243   AE1321   sd_beam_10b
    246. 244   AE1418   sd_beam_10b_off
    247. 245   AE1322   sd_beam_10c
    248. 246   AE1419   sd_beam_10c_off
    249. 247   AE1323   sd_beam_15a
    250. 248   AE141A   sd_beam_15a_off
    251. 249   AE1324   sd_beam_6a
    252. 250   AE141B   sd_beam_6a_off
    253. 251   AE1325   sd_beam_6b
    254. 252   AE141C   sd_beam_6b_off
    255. 253   AE1326   sd_beam_6c
    256. 254   AE141D   sd_beam_6c_off
    257. 255   AE1327   sd_beam_7a
    258. 256   AE1328   sd_foot_1
    259. 257   AE1329   sd_foot_2
    260. 258   AE132A   sd_foot_3
    261. 259   AE132B   sd_foot_4
    262. 260   AE132C   sd_foot_5
    263. 261   AE132D   sd_foot_6
    264. 262   AE132E   sd_robo_1a
    265. 263   AE132F   sd_robo_1b
    266. 264   AE1330   sd_robo_1c
    267. 265   AE1331   sd_robo_2a
    268. 266   AE1332   sd_robo_2c
    269. 267   AE1333   sd_robo_3a
    270. 268   AE1334   sd_robo_3b
    271. 269   AE1335   sd_robo_5a
    272. 270   AE1336   sd_robo_5b
    273. 271   AE1337   sd_robo_5c
    274. 272   AE1338   sd_bean_damage_01
    275. 273   AE1339   sd_bean_damage_02
    276. 274   AE133A   sd_bean_kwa_01
    277. 275   AE133B   sd_bean_kwe_01
    278. 276   AE133C   sd_bean_longescream_01
    279. 277   AE133D   sd_bomb_1
    280. 278   AE133E   sd_bomb_2
    281. 279   AE133F   sd_b_fence_2
    282. 280   AE141E   sd_b_fence_2_off
    283. 281   AE1340   sd_b_fence_3
    284. 282   AE1341   sd_ele_1
    285. 283   AE1342   sd_ele_2
    286. 284   AE1343   sd_ele_3
    287. 285   AE141F   sd_ele_3_off
    288. 286   AE1344   sd_ele_4
    289. 287   AE1345   sd_engine_1
    290. 288   AE1420   sd_engine_1_off
    291. 289   AE1346   sd_shatter_1
    292. 290   AE1347   sd_shatter_3
    293. 291   AE1348   sd_torocco_2
    294. 292   AE1421   sd_torocco_2_off
    295. 293   AE1349   sd_zaza
    296. 294   AE134A   sd_tyu_13a
    297. 295   AE134B   sd_tyu_13b
    298. 296   AE134C   sd_tyu_13d
    299. 297   AE134D   sd_tyu_13e
    300. 298   AE134E   sd_tyu_13ff
    301. 299   AE134F   sd_tyu_13fff
    302. 300   AE1350   sd_tyu_13gg
    303. 301   AE1351   sd_tyu_13ggg
    304. 302   AE1352   sd_tyu_2
    305. 303   AE1353   sd_tyu_2a
    306. 304   AE1354   sd_tyu_3
    307. 305   AE1355   sd_tyu_3a
    308. 306   AE1356   sd_tyu_4
    309. 307   AE1357   sd_tyu_4a
    310. 308   AE1358   sd_laugh0b
    311. 309   AE1359   sd_bowling
    312. 310   AE1000   sd_game_bgm_00
    313. 311   AE1001   sd_game_bgm_01
    314. 312   AE1002   sd_game_bgm_02
    315. 313   AE1003   sd_game_bgm_03
    316. 314   AE1004   sd_game_bgm_04
    317. 315   AE1005   sd_game_bgm_05
    318. 316   AE1006   sd_game_bgm_06
    319. 317   AE1007   sd_game_bgm_07
    320. 318   AE1008   sd_game_bgm_08
    321. 319   AE1009   sd_game_bgm_09
    322. 320   AE100A   sd_game_bgm_0a
    323. 321   AE100B   sd_game_bgm_0b
    324. 322   AE100C   sd_game_bgm_0c
    325. 323   AE100D   sd_game_bgm_0d
    326. 324   AE100E   sd_game_bgm_0e
    327. 325   AE100F   sd_game_bgm_0f
    328. 326   AE1010   sd_game_bgm_10
    329. 327   AE1011   sd_game_bgm_11
    330. 328   AE1012   sd_game_bgm_12
    331. 329   AE1013   sd_game_bgm_13
    332. 330   AE1014   sd_game_bgm_14
    333. 331   AE1015   sd_game_bgm_15
    334. 332   AE1016   sd_game_bgm_16
    335. 333   AE1017   sd_game_bgm_17
    The format is: AE 1b nn with "b" being the sound bank and nn being the ID within the bank.
     
    Last edited: Sep 12, 2020
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  14. biggestsonicfan

    biggestsonicfan

    Model2wannaB Tech Member
    1,608
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    ALWAYS Sonic the Fighters
    Thanks much for this! Is it alright if I include this in the disassembly repo?
     
  15. ValleyBell

    ValleyBell

    Tech Member
    246
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    researching PC-98/X68000 sound drivers
    Feel free to do so.
     
  16. biggestsonicfan

    biggestsonicfan

    Model2wannaB Tech Member
    1,608
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    ALWAYS Sonic the Fighters
    Yay! Now to figure out a way to take the extracted samples and midis and put them back into the game :british:
     
  17. Tiberious

    Tiberious

    Yeah, I'm furry. Got a problem? Oldbie
    777
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    I'm watching this with interest. Personally, I've always wanted to see either a fan or official sequel to this game, now that there's more characters to work with, and hopefully fix up some system/balance issues in the process (some characters are outright broken within the system as it is now). I've brainstormed a few, vague ideas on what could be done, but nothing I can really turn a critical eye on.

    But good thing with this is I bet you could at least make some good balance changes. Sonic shouldn't be able to completely remove the opponent's ability to block for the rest of the match in the first seconds of the first round, for instance.

    What are your plans with this?
     
  18. biggestsonicfan

    biggestsonicfan

    Model2wannaB Tech Member
    1,608
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    ALWAYS Sonic the Fighters
    Well, the main goal is to document and create a point of reference for which someone much smarter than me can use Ghidra and take that I have and compare it and eventually turn it into C-like code for mucking about, much like the Super Mario 64 disassembly. That's never going to become a reality though, so realistically this is just going to become an open-ended project where we learn a bit and get some new takeaways from secrets the game holds.

    There's a lot going on in this game's engine where we can't fully understand it without also disassembling both Fighting Vipers and Virtua Fighter 2, as a lot of variables listed in the debug menu simply go unused or unrefrenced in Sonic the Fighters, where they could be implemented in the other games. So to get the full picture of the game's engine and what it is capable of may never manifest itself.
     
  19. Scorched Dreamer

    Scorched Dreamer

    Tudd Member
    16
    6
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    Linz, Austria
    Pier Pressure [Headcannon]
    Rooting for this! I've always found it to be such a fascinating game, being developed by AM2.. The sound in particular. I'd be really interested in looking at the MIDI and SF2 files, but I'm not particularly good at compiling and using C code

    Keep up the good work!!
     
  20. biggestsonicfan

    biggestsonicfan

    Model2wannaB Tech Member
    1,608
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    ALWAYS Sonic the Fighters
    Thank you very much!

    Today, I would like to do something a little different. Cheats have traditionally been made in the scripts of the emulator's engine, like displaying numbers and values, but I wondered if I could make a "cheat" within the game's engine itself. Something that could run on hardware. Well, yes, yes I can.

    There is an odd routine I've labeled as "CPU_USE_MOVE".

    Code (Text):
    1. CPU_USE_MOVE:
    2.                 ldob    0xC9(g4), r3
    3.                 ld      debug_cpu_movesets[r3*4], r4 # Sets proper character moveset
    4.                 ldob    0xBA(g4), r3
    5.                 addo    0x1F, 0xD, r5
    6.                 mulo    r5, r3, r3
    7.                 lda     (r4)[r3], r5
    8.                 mov     r5, g0          # sets move ascii location to g0, then returns
    9.                 call    CPU_USE_MOVE_return
    10.                 lda     0xC(r5), r6
    11.                 lda     0x1C(r5), r7
    12.                 ldob    0xC5(g4), r8
    13.                 cmpibl  0x10, r8, loc_3E5D0
    14.                 ldob    (r6)[r8], g5
    15.                 lda     0x7F, r5
    16.                 cmpobe  r5, g5, loc_3E5D0
    17.                 call    sub_3E6A4
    18.                 stob    g5, 0x1200(g7)
    19.                 stob    g5, 0xC7(g4)
    20.                 ldob    (r7)[r8], r3
    21.                 stob    r3, 0xC6(g4)
    22.                 cmpobne 0, r3, loc_3E5CC
    23.                 ldob    0xC5(g4), r14
    24.                 addi    1, r14, r15
    25.                 stob    r15, 0xC5(g4)
    26. loc_3E5CC:
    27.                 ret

    This routine loads up the current computer player's moveset and loads the currently executing move's ascii location to register g0. It then calls a subroutine which just returns, so it goes back to executing code. I bet this subroutine once provided debug information showing what move a CPU was using. So I decided to restore something like that.

    To start with, I decided to use a 100% unreferenced area of ROM to start writing my own routine in, and "DEBUG_UNUSED_MENU" fits that bill perfectly. So long as I keep the same amount of bytes used in my custom code, I can do whatever I want.

    First, I need to alter "CPU_USE_MOVE" to call "DEBUG_UNUSED_MENU" instead of "CPU_USE_MOVE_return". That's just a simple like so:
    Code (Text):
    1. call    DEBUG_UNUSED_MENU
    Next, we need to write the code that will run in DEBUG_UNUSED_MENU. Text displays using register "g0" as the ascii text and register "g9" as the coordinate. So if we look at the code above for "CPU_USE_MOVE", we can see that the location of the ascii of a move is loaded to g0, but not the ascii itself, so the first line of code we need is as follows:
    Code (Text):
    1. ld     (g0), g0
    Great, now g0 is loaded with the ascii value that was located at g0 previously!

    Now I don't understand the coordinate system enough yet to place text wherever I want, but I DO know that when the game boots up, it lists some text in the top left corner of the screen, so I'm going to copy the disassembled code from there to use as our coordinates to place text:
    Code (Text):
    1. lda     0x1000014, g9
    Alright, almost done. Now we need to call the routine that places text on the screen, like so:
    Code (Text):
    1. call    uk__dispText
    And finally, we need to jump back to the "CPU_USE_MOVE" routine with a return:
    Code (Text):
    1. ret
    Giving us the resulting code:
    Code (Text):
    1. DEBUG_UNUSED_MENU:
    2.                 ld     (g0), g0
    3.                 lda     0x1000014, g9
    4.                 call    uk__dispText
    5.                 ret
    Assembling this code into the ROM allows us to view the CPU player move names as they execute, like so:

    sfight034.png

    But you don't have to do all this because I wrote an emulator cheat so you can play with this cheat too!

    Simply add
    Code (Text):
    1. function show_cpu_move()
    2.     Romset_PatchDWord(0,0x3E584, 0x0900963C)
    3.  
    4.     Romset_PatchDWord(0,0x47BC0, 0x90841000)
    5.     Romset_PatchDWord(0,0x47BC4, 0x8CC83000)
    6.     Romset_PatchDWord(0,0x47BC8, 0x01000014)
    7.     Romset_PatchDWord(0,0x47BCC, 0x09FBDAA8)
    8.     Romset_PatchDWord(0,0x47BD0, 0x0A000000)
    9. end
    To "sfight.lua" and call "show_cpu_move()" under "Init()" like so:
    Code (Text):
    1. function Init()
    2.      show_cpu_move()
    3. end
    Have fun!
     
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