Akumajou Dracula X68000 uses a hacked dump instead of the unmodified one

[HazukiXX]

MAME version

0.257

Emulated system/software

X68000/akumajo

Incorrect behaviour

MAME uses the wrong dump of the game. It's the easy hack where every enemy only gives you 1 point of damage.

Expected behaviour

Enemies from stage 1 should give you 2 points of damage, 3 points on stage 2 and 4 from stage 3 and onward.

Steps to reproduce

Run the game, take damage from the first zombie enemy and watch as you only take 1 point of damage instead of 2.

[rb6502]

Replacing bad dumps in software lists is a great way to contribute without needing any real technical skills. It's fine if you'd rather not, but I always like to throw that out there when reports like this happen.

[Firehawke]

If nobody has fixed this yet, I'll go see if I can't dig up a correct dump.

[Firehawke]

I've compared what we have to what's in Sharp X68000 - Games - [DIM] (TOSEC-v2014-05-13_CM).datthat is included in the current TOSEC - DAT Pack - Complete (3983) (TOSEC-v2023-07-10) and it's a 100% match. If this is an incorrect dump, this issue should be brought to the upstream at TOSEC.

[etabeta78]

Our xml software lists for Japanese computer have vastly superseded whatever dats images were taken from. This means we that we shall flag this as bad dump as well as bring the issue to TOSEC if they want to rectify their dats as well

In the meanwhile, let’s hope some of the people behind Japanese disk torrents can source a better cop

On Wednesday, April 3, 2024, Firehawke @.***> wrote:

I've compared what we have to what's in Sharp X68000 - Games - [DIM] (TOSEC-v2014-05-13_CM).datthat is included in the current TOSEC - DAT Pack - Complete (3983) (TOSEC-v2023-07-10) and it's a 100% match. If this is an incorrect dump, this issue should be brought to the upstream at TOSEC.

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[einstein95]

Looking at the alternate dumps in TOSEC's dat and Akumajou Dracula (1993)(Konami)(Disk 1 of 2)[a].dim (<rom name="akumajou dracula (1993)(konami)(disk 1 of 2)[a].dim" size="1261824" crc="4145035d" sha1="63d7ea781b36db6920fb36c0fd75dcba4c475384" />) has enough differences to be probably considered the original:

1. the executable filename is DRA.X vs dra.x
2. the executable has 3 bytes different (using the locations in RAM):

      MAME                  -> Alt
   702f2: 6018  bra     $7030c  -> 6718  beq     $7030c
   95f5e: 7000  moveq   #$0, D0 -> 5340  subq.w  #1, D0

   The 2nd change is the one that is responsible for the decreased life loss.

In addition, akumajou dracula (1993)(konami)(disk 2 of 2).dim is the only version of the 2nd disk in TOSEC that has BLK0_V.DAT with 41 FA 0F 3A at 0x5257 rather than 7E 00 4E 75, though I'm unsure of what this changes.

[cuavas]

TOSEC quality really isn’t that good.

@rzero9 – as the person who’s done the most to replace bad dumps for the Japanese computers, do you know anything about this one?

[rb6502]

In addition, akumajou dracula (1993)(konami)(disk 2 of 2).dim is the only version of the 2nd disk in TOSEC that has BLK0_V.DAT with 41 FA 0F 3A at 0x5257 rather than 7E 00 4E 75, though I'm unsure of what this changes.

I'd suspect a copy protection crack but I don't know if X68K games had any disk-based protection.

[angelosa]

x68k has plenty of disk copiers like any other Jp computer ("The File Master" for example), and sounds very logical that the TOSEC dumps can have cracked disks ...

[rzero9]

TOSEC quality really isn’t that good.

@rzero9 – as the person who’s done the most to replace bad dumps for the Japanese computers, do you know anything about this one?

In terms of gameplay changes, I can't confirm or deny anything as I don't have access to the original to compare (unless we count the Castlevania Chronicles version), but all Konami X68000 games I've come across have on-disk protection (and a pretty nasty one, with overlapped sectors that cover the entire length of a track and is really hard to represent in a format that MAME understands; Detana! Twinbee only worked by some kind of miracle), which means every image of Dracula out there is probably modified in some way.

Since it's very unlikely that a playable dump of the original disks will show up in MAME any time soon. If one of the alts in TOSEC is indeed closer to the original behavior, I think it would be a good idea to add it.

[HazukiXX]

@Firehawke – Yes, that one dump is 100% clean. You can replace the current one with it safely.