Author Topic: Bio Hazard (and a few other Waixing games)  (Read 3705 times)

NewRisingSun

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Bio Hazard (and a few other Waixing games)
« on: February 15, 2018, 02:58:10 PM »
There are two known versions of Bio Hazard from Waixing: a regular version using Mapper 15, and a version found among Waixing's downloadable NES games using Mapper 227. The Mapper 227 version works flawlessly in emulators that support this mapper, while the Mapper 15 version will sooner or later freeze, usually early in the game. (There is also a differently-named version from Henge Dianzi which again uses a completely different mapper.)

I investigated the issue and found that the Mapper 15 version is just a mapper hack of the mapper 227 version. The bankswitching code appears at the start of every 32 KiB bank, and this is the only place where the two versions differ. Mapper 15's bankswitching code takes fewer bytes (17) than Mapper 227's, and after those 17 bytes in the Mapper 15 version, there are the remnants of Mapper 227's bankswitching code. This proves that the Mapper 15 version must be a (bad) mapper hack, and that the Mapper 227 version is the original version.

I further found that all Waixing mapper 15 ROM images are mapper hacks, judging by the fact that in each of these games, the Mapper 15 bankswitching code is followed by now-unreachable remnants of bankswitching code for a different mapper:
  • 笑傲江湖 (Xiào ào Jiānghú)
  • 爆笑三國 (Bàoxiào Sānguó)
  • 外星戰士2 (Wàixīng Zhànshì 2)
  • 上海大亨 - Shanghai Tycoon
Waixing's downloadable games include the original unhacked version of Xiào ào Jiānghú as well. The other three are not available in their original unhacked versions: while the games are of course downloadable as well, the downloadable versions have been greatly modified from their original cartridge releases. This means that Bàoxiào Sānguó, Wàixīng Zhànshì 2 and Shanghai Tycoon need to be redumped. I think their original mapper must have been 227 as well, though it can only be said with certainty once one tries actually dumping one of these cartridges.

KAGE-008

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Bio Hazard (and a few other Waixing games)
« Reply #1 on: February 17, 2018, 01:12:57 PM »
Hengge's version of Biohazard runs on mapper 241 and also older versions of the emulators can run it. There is a version of WXZS2 with its original title, Meng Huan Zhi Xing IV which runs on mapper 176 IIRC.

NewRisingSun

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Bio Hazard (and a few other Waixing games)
« Reply #2 on: February 17, 2018, 01:50:34 PM »
Yes, Henge Dianzi used their own mappers and modified existing games for that purpose when they released them. (I still don't know whether Henge pirated Waixing's games or whether theirs are legitimate releases.) Waixing started using their FS005 board (Mapper 176, using FK23C hardware) sometime in the mid-2000s and modified most of their existing games for it, which are the versions found in the downloadable WXN archive. But those modifications are skillfully done, some of them even visibly from original source code, unlike those mapper 15 hacks.
Henge Dianzi games set to 241 should be set to 177, but since the mappers are so similar, it makes little difference, so the distinction is pedantic for most games.

The available ROM image Meng Huan Zhi Xing IV that uses Mapper 176 can only be a later re-release, as the Waixing FS005 board (Mapper 176) certainly did not exist in 1996. I have added the original version of Meng Huan Zhi Xing IV to the dump needed wiki page.
« Last Edit: February 18, 2018, 05:58:35 AM by NewRisingSun2 »

NewRisingSun

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Bio Hazard (and a few other Waixing games)
« Reply #3 on: February 25, 2018, 05:09:17 AM »
I already posted the unhacked Mapper 227 version of Bio Hazard as part of my December 10th Multicart Extracts release, but here it is again, along with the Henge Dianzi release.

Attachments:
« Last Edit: February 25, 2018, 05:16:31 AM by NewRisingSun2 »

dragon2snow

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Bio Hazard (and a few other Waixing games)
« Reply #4 on: February 25, 2018, 05:36:27 AM »
this game first rom dump by my master tpu
tpu add dumper info in Raw DATA......,to BUG