Difference between revisions of "Mega Drive Unlicensed Game Emulation Notes"

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Furthermore, the Z80 sound driver presumably expects that the uppermost 32KB of ROM (from $1F8000) be mirrored at $400000. This needs to be confirmed.
 
Furthermore, the Z80 sound driver presumably expects that the uppermost 32KB of ROM (from $1F8000) be mirrored at $400000. This needs to be confirmed.
 +
 +
cmpi.b  #$C9,($400004).l
 +
cmpi.b  #$18,($400006).l
  
 
[[Category:Emulation]]
 
[[Category:Emulation]]

Revision as of 11:25, 13 August 2011

TODO: Is there a better category? And I have to add everything =P (plus ROM addresses, SRAM specifics, etc.)

Unlike official Mega Drive games, unlicensed games usually have copy protection schemes, SRAM mapping oddities, or other hardware quirks that emulator authors should take note of if they want their emulators to work with these games. sha1sums of dumps to watch out for are given.

Note that at present, no unlicensed game is known to use Sega's standard checksum routine, so checksum fixing should NOT be done to these games (especially since some, for example Aq Renkan Awa, are known to store code at $18E).

Checklist for keeping track of what I'm doing

To be edited as time goes on. .gen is from GoodGen and .md is from no-intro, with the no-intro names taking precedence (I'll take care of that later) 

12-in-1 (Unl) [!].gen
16 Tiles Mahjong (Unl) [b1].gen
16 Tiles Mahjong (Unl).gen
16 Tiles Mahjong (Unl) [h1C].gen
777 Casino (Unl).gen
777 Casino (Unl) [h1C].gen
777 Casino (Unl) [h2C].gen
Action 52 (Unl) [a1][!].gen
Action 52 (Unl) [b1].gen
Action 52 (Unl) [b2].gen
Action 52 (Unl) [!].gen
Action 52 (Unl) [h1C].gen
Action 52 (Unl) [h2C].gen
Action 52 (Unl) [h3C].gen
Action Replay (Unl) [!].gen
Aladdin II (Unl).gen
Aq Renkan Awa (Unl).gen
Barver Battle Saga - The Space Fighter (Ch) [a1].gen
Barver Battle Saga - The Space Fighter (Ch).gen
Barver Battle Saga - The Space Fighter (V0.9) (Ch).gen
Bible Adventures (Unl) [!].gen
Bible Adventures (Unl) [h1C].gen
Bug's Life, A (Unl) [f1].gen
Bug's Life, A (Unl) [f2].gen
Bug's Life, A (Unl) [!].gen
Bug's Life, A (Unl) [h1C].gen
CDX Pro BIOS V1.70 (Unl) [b1].gen
CDX Pro BIOS V1.8I (Unl).gen
CDX Pro BIOS V1.8I (Unl) [o1].gen
Chaoji Dafuweng (Unl) [!].gen
Chess (Unl) [!].gen
Chinese Chess (Unl) [b1].gen
Chinese Chess (Unl).gen
Conquering the World III (Ch-Simple).gen
Conquering the World III (Ch-Trad).gen
Devilish Mahjong Tower (Unl) [b1].gen
Devilish Mahjong Tower (Unl) [b2].gen
Devilish Mahjong Tower (Unl) [b3].gen
Devilish Mahjong Tower (Unl).gen
Dial Q o Mawase! (Unl).gen
Dial Q o Mawase! (Unl) [h1C].gen
Dial Q o Mawase! (Unl) [T+Chi].gen
Divine Sealing (Unl) [!].gen
Divine Sealing (Unl) [h1C].gen
Divine Sealing (Unl) [h2C].gen
Domino (Unl).gen
Earth Defend, The (Unl) [b1].gen - not sure what happened here
Elf Wor (Unl) [h1C].gen - this is a header hack so still needs the copy protection; IDK if I should throw it in...
Exodus (Unl) [!].gen
Fengshen Yingjiechuan (Ch).gen
Fido Dido (Unl) [b1].gen
Fido Dido (Unl).gen
FIFA Soccer 2000 Gold Edition (Unl) (M6) [!].gen
Fun Car Rally (Unl) [b1].gen
Fun Car Rally (Unl).gen
Fun Car Rally (Unl) [h1C].gen
Fun Car Rally (Unl) [h2C].gen
Futbol Argentino 98 - Pasion de Multitudes (Unl).gen
Gamtec Magicard (Unl) [!].gen
Ghost Hunter (Unl) [b1+C].gen
Ghost Hunter (Unl) [b1].gen
Ghost Hunter (Unl) [b2].gen
Ghost Hunter (Unl).gen
Hercules 2 (Unl).gen
Hercules (Unl) [!].gen
Iraq War 2003 (Unl).gen
Joshua & the Battle of Jericho (Unl) [!].gen
King of Fighters '98, The (Unl) [!].gen
King of Fighters '98, The (Unl) [p1][!].gen
Link Dragon (Unl).gen
Link Dragon (Unl) [h1C].gen
Lion King 3 (Unl) [f1].gen
Lion King 3 (Unl).gen
Lion King II, The (Unl) [!].gen
Lion King II, The (Unl) [p1][!].gen
Magic Girl (Unl) [!].gen
Magic Girl (Unl) [h1C].gen
Magic Girl (Unl) [t1].gen
Mahjong Lover (Unl) [!].gen
Mega Bomberman - 8 Player Demo (Unl).gen
Mega Bomberman - 8 Player Demo (Unl) [h1C].gen
Mega Bomberman - 8 Player Demo (Unl) [h2C].gen
Mega Bomberman - 8 Player Demo (Unl) [h3C].gen
MK 5 - Mortal Combat - SubZero (Unl) [!].gen
MK 5 - Mortal Combat - SubZero (Unl) [p1][!].gen
Mulan (Unl) [f1].gen
Mulan (Unl) [f2].gen
Mulan (Unl) [!].gen
Pocket Monsters 2 (Unl) [f1].gen
Pocket Monsters 2 (Unl) [!].gen
Pocket Monsters (Unl) [a1][f1].gen
Pocket Monsters (Unl) [a1][!].gen
Pocket Monsters (Unl) [f1].gen
Pocket Monsters (Unl) [!].gen
Pokemon Crazy Drummer (Unl).gen
Pretty Girl Mahjongg (Ch).gen
Pretty Girl Mahjongg (Ch) [h1C].gen
Pretty Girl Mahjongg (Ch) [h2C].gen
Pro Action Replay 2 V2.1 (Unl) [!].gen
Pro Action Replay (Unl) [!].gen
Rockman X3 (Unl) [b1].gen
Rockman X3 (Unl) [b2].gen
Rockman X3 (Unl) [f1].gen
Rockman X3 (Unl) [!].gen
Romance of the Three Kingdoms Part 5 (Ch).gen
Sangokushi Retsuden (Ch).gen
Sangokushi Retsuden (Ch) [h1C].gen
Sangokushi Retsuden (Ch) [h2C].gen
Sega Subor System Cartridge (Unl).gen
Smart Mouse (Unl) [h1C].gen - this is a header hack so still needs the copy protection; IDK if I should throw it in...
Sonic Jam 6 (Unl) [f1].gen
Sonic Jam 6 (Unl) [f1][o1].gen
Sonic Jam 6 (Unl) [f2].gen
Sonic Jam 6 (Unl) [!].gen
Sonic Jam 6 (Unl) [p1][!].gen
Soul Blade (Unl) [!].gen
Spiritual Warfare (Unl) [!].gen
Spiritual Warfare (Unl) [h1C].gen
Spiritual Warfare (Unl) [h2C].gen
Super Chinese Tycoon (Unl) [f1].gen
Super Donkey Kong 99 (Unl) [f1].gen
Super Donkey Kong 99 (Unl) [!].gen
Super Donkey Kong 99 (Unl) [h1C].gen
Super King Kong 99 (Unl) [!].gen
Super Mario 2 1998 (Unl) [f1].gen
Super Mario 2 1998 (Unl) [!].gen
Super Mario 2 1998 (Unl) [o1][f1].gen
Super Mario 2 1998 (Unl) [o1].gen
Super Mario Bros. (Unl) [f1].gen
Super Mario Bros. (Unl) [!].gen
Super Mario World (Unl) [f1].gen
Super Mario World (Unl) [!].gen
Super Mario World (Unl) [p1][!].gen
Taiwan Tycoon (Unl) [b1].gen
Taiwan Tycoon (Unl).gen
Tekken 3 Special (Unl).gen
Tiger Hunter Hero Novel (Ch).gen
Top Fighter 2000 MK VIII (Unl) [f1].gen
Top Fighter 2000 MK VIII (Unl) [!].gen
Top Shooter (Unl).gen
TotoTek Multi-Game Menu V1.00 (Unl).gen
Unknown Chinese Game 1 (Ch).gen - Feng Shen Ying Jie Chuan; not sure if different
Unknown Chinese Game 2 (Ch).gen - Shui Hu Zhuan; not sure if different
Virtua Fighter 2 vs Tekken 2 (Unl) [b1].gen
Virtua Fighter 2 vs Tekken 2 (Unl) [b2].gen
Virtua Fighter 2 vs Tekken 2 (Unl).gen
Virtua Fighter 2 vs Tekken 2 (Unl) [h1C].gen
Whac-A-Critter (Unl) [f1].gen - it definitely circumvents the copy protection but not in a way that I understand by just looking at a binary difference...
World Pro Baseball 94 (Unl).gen
Yang Warrior Family, The (Ch).gen
Ya-Se Chuan Shuo (Ch) [f1].gen - not sure how it was fixed; need to check later
Ya-Se Chuan Shuo (Ch) [f2].gen - not sure how it was fixed; need to check later


16 Zhang Ma Jiang (China) (Unl).md
Action 52 (USA) (Alt) (Unl).md
Action 52 (USA) (Unl).md
Adventurous Boy - Mao Xian Xiao Zi (China) (Unl).md
Aq Renkan Awa (China) (Unl).md
Barver Battle Saga - Tai Kong Zhan Shi (China) (Unl).md
Bible Adventures (USA) (Unl).md
Chao Ji Da Fu Weng (China) (Unl).md
Dial Q o Mawase! (Japan) (Unl).md
Divine Sealing (Japan) (Unl).md
Exodus - Journey to the Promised Land (USA) (Unl).md
Feng Kuang Tao Hua Yuan (China) (Unl).md
Feng Shen Ying Jie Chuan (China) (Unl).md
Hei Tao 2 - Super Big 2 (China) (Unl).md
Hua Mu Lan - Mulan (China) (Unl).md
Jiu Ji Ma Jiang II - Ye Yan Bian (China) (Unl).md
Joshua & The Battle of Jericho (USA) (Unl).md
Long (China) (Unl).md
Ma Jiang Qing Ren - Ji Ma Jiang Zhi (China) (Unl).md
Ma Qiao E Mo Ta - Devilish Mahjong Tower (China) (Unl).md
Meng Huan Shui Guo Pan - 777 Casino (China) (Unl).md
San Guo Zhi V (China) (Unl).md
Shi Jie Zhi Bang Zheng Ba Zhan - World Pro Baseball 94 (China) (Unl).md
Shui Hu - Feng Yun Zhuan (China) (Unl).md
Shui Hu Zhuan (China) (Unl).md
Spiritual Warfare (USA) (Unl).md
Squirrel King (China) (Unl).md
Taiwan Daheng (China) (Unl).md
Tun Shi Tian Di III (China) (Simple Chinese) (Unl).md
Tun Shi Tian Di III (China) (Unl).md
Wu Kong Wai Zhuan (China) (Unl).md
Xiao Monv - Magic Girl (China) (Unl).md
Yang Jia Jiang - Yang Warrior Family (China) (Unl).md
Zhuo Gui Da Shi - Ghost Hunter (China) (Unl).md

Games With Constant-Value Hardware Registers

TODO many, many, many more

A large number of unlicensed games merely read various constant byte values stored at specific addresses in the $400000 region as copy protection.

Game sha1sum $400000 $400002 $400004 $400006 On Failure
Elf Wor 5fc4591fbb1acc64e184466c7b6287c7f64e0b7a $55 $F $C9 $18
Huan Le Tao Qi Shu: Smart Mouse df7a2527875317406b466175f0614d343dd32117 $55 $F $AA $F0 The game will fade to black and freeze several seconds into gameplay. Check is at ROM $8BC.
Mighty Morphin' Power Rangers: The Fighting Edition 25d2d6a5ab20e16b8b42b67e5fb338421b64b29b $55 $F $18
Super Bubble Bobble MD 03f40c14624f1522d6e3105997d14e8eaba12257 $55 $F It will play a high-pitched beeping sound and refuse to go past the beginning of the title screen. This check is at ROM $123E4.

Additional Game Specifics

Elf Wor

The game checksums the two that do the copy protection check and will refuse to boot if the checksums do not match: 

ROM:000003EC                 lea     ($5166).l,a0    ; what this routine does is presently unknown (TODO)
ROM:000003F2                 move.w  #$2FF,d7
ROM:000003F6                 move.w  #0,d0
ROM:000003FA
ROM:000003FA loc_3FA:                                ; CODE XREF: ROM:000003FC�j
ROM:000003FA                 add.b   (a0)+,d0
ROM:000003FC                 dbf     d7,loc_3FA
ROM:00000400                 cmpi.b  #$5E,d0
ROM:00000404                 beq.w   loc_40E         ; next check
ROM:00000408                 jmp     (loc_300).l     ; back to entry point == no boot
ROM:0000040E ; ---------------------------------------------------------------------------
ROM:0000040E
ROM:0000040E loc_40E:                                ; CODE XREF: ROM:00000404�j
ROM:0000040E                 lea     ($1AAE).l,a0    ; this is the player event handling routine
ROM:00000414                 move.w  #$1FF,d7
ROM:00000418                 move.w  #0,d0
ROM:0000041C
ROM:0000041C loc_41C:                                ; CODE XREF: ROM:0000041E�j
ROM:0000041C                 add.b   (a0)+,d0
ROM:0000041E                 dbf     d7,loc_41C
ROM:00000422                 cmpi.b  #$94,d0
ROM:00000426                 beq.w   sub_430         ; boot!
ROM:0000042A                 jmp     (loc_300).l     ; back to entry point == no boot

Mighty Morphin' Power Rangers: The Fighting Edition

(TODO cleanup this part) According to Eke, author of Genesis Plus GX: 

00065D2E:6000 ; bypass a first check
00065D3A:070A ; fixes internal checksum so it matches original value

000661FC:6000 ; bypass a second check
00066208:070A ; fixes internal checksum so it matches original value

Additionally there's a routine that overwrites ROM to thwart copiers (TODO)

Super Bubble Bobble MD

The game also stores stuff in the $200000-$3FFFFF range and reads stuff back from it; exactly what this should be is unknown (TODO).

Games That Use Mirrored Memory For Copy Protection

TODO not as many: Tiny Toon Adventures 3, Barver Battle Saga, Shui Hu Zhuan, Feng Shen Ying Jie Chuan, and Squirrel King are the only five I know of so far

Some games store memory instead of constant values at the $400000 area, writing byte values to one address and expecting to read them back from a different address. While each game uses different pairs of addresses (some even switching between pairs), all of them will still work if the expected value is read back from all addresses, which would be the safest option for emulator authors.

Additional Game Specifics

Games With Rockman X3-style ROM Banking

TODO this one will hurt

Games With Super Donkey Kong 99-style ROM Banking

TODO so will this

All Realtec Games

TODO: wikify this

Affected ROMs:

All Realtec games use a custom mapper format documented by TascoDLX.

Tiny Toon Adventures 3

Affected ROMs:

The game writes byte $55 to $400000 (this address is stored in memory by a calculation at $673E and the byte is stored in the function starting at $2C0C) and expects to read that byte back from $400002; otherwise, the game will reset itself (function with this check is at $2C26).

The game also appears to write to the upper 64KB of ROM (from $F0000 on), but doesn't appear to actually use that area (TODO).

Xin Qi Gai Wang Zi

Affected ROMs:

  • Xin Qi Gai Wang Zi: presently undumped
  • Dumps of pirate versions: 75f8003a6388814c1880347882b244549da62158, 4a7494d8601149f43ba7e3595a0b2340cde2e9ba

The game is 4MB storing SRAM above the $400000 mark. (TODO get specifics)

Ya Se Chuan Shuo

Affected ROMs:

  • "Imperial Dynasty" version: presently undumped
  • "The Legend of Arthur" version: 8fe0806427e123717ba20478ab1410c25fa942e6

The Data East/Side Pocket driver stolen from High Seas Havoc used in this game is slightly modified; an add from Z80 RAM to a register (TODO) is used. If this instruction is not emulated correctly, the play song routine will load invalid music and eventually crash.

Furthermore, the Z80 sound driver presumably expects that the uppermost 32KB of ROM (from $1F8000) be mirrored at $400000. This needs to be confirmed.

cmpi.b #$C9,($400004).l cmpi.b #$18,($400006).l

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