House of the dead 2 prototype on a real Naomi

[PlatynumX]

@skate323k137

I know I'm not breaking ground here as it's essentially an ic22 swap but others might learn from this.

Backstory I spent too much time on x(fka Twitter) at the end of July. 'wiki of the dead' shows up in my feed and I give them a follow(hotd series fan if isn't obvious). One of their posts was a screenshot of hotd2 title screen but it was different. It had a subtitle : original sin. Wtf is this I asked myself. A Google search taught me the prototype name was hotd2:original sin and a mame dump of it existed. I learned looking through all the hotd2 mame files that the only difference in game roms(prototype or normal region versions) was the ic22 file and having to use the prototype bios(the bios bit turned out to be wrong). I renamed the ic22 and made a new hotd2 rom zip. I command line launched mame with my new rom zip file. Ran as well as to be expected (I don't keep up with Naomi emulation but it chugged. My PC can emulate PS3 games fine ). I hit up skate to burn me the prototype bios and ic22. Usps seemingly lost them for 2 weeks and they magically showed up today. Guess what?
I've got hotd2:original sin running on my cab on a stock hotd2 bios. I was too lazy to remove the game PCB and bios swap . Metal cage Naomis are a pita.

There are a few differences.
I immediately noticed the timing of the music and the announcer saying house of the dead,the flame animation being different and minor mutant texture differences.i only casually played through the first level. I know the game ends at the coliseum.

The test menu is different

The sub menus have smaller font/different resolution

And a different loading screen

Kind of bad things about this:green blood only and Japanese in game text.


Tldr: have skate323k137 burn you the hotd2 prototype ic22 and you can convert your hotd2 PCB into the prototype version. Unlike the mvc2 unlocked ic22 you don't need to swap games for the new ic22 to load

 

[skate323k137]

That's awesome, thanks for the thorough write up and letting me prepare your chips

And I'm glad the first ones appeared because the receipt for the replacement packages label has vanished from my PayPal . Hopefully you get that package too eventually, and if so, feel free to keep them or pass them on.

 

[MetalliC]

@PlatynumX good work
but, if anyone have NAOMI 1/2 with NetDIMM and guns there is simpler way -
grab proto hod2 IC22 dump from MAME romset, grab netboot HOD2 binary, open them in HEX editor, copy proto IC22 contents and paste it at the very beginning of netboot binary
that's it, took few second to complete

 

[skate323k137]

@PlatynumX good work
but, if anyone have NAOMI 1/2 with NetDIMM and guns there is simpler way -
grab proto hod2 IC22 dump from MAME romset, grab netboot HOD2 binary, open them in HEX editor, copy proto IC22 contents and paste it at the very beginning of netboot binary
that's it, took few second to complete

Isn't the stock HOTD2 BIOS pre-netdimm support? Not saying I don't believe you or anything just the first thought that comes to mind.

 

[nem]

IIRC the BIOS is included in the netboot binary of HOTD2. It doesn't matter what BIOS is on the motherboard.

 

[skate323k137]

IIRC the BIOS is included in the netboot binary of HOTD2. It doesn't matter what BIOS is on the motherboard.

That's interesting. I don't fully understand how it's possible, wouldn't the main board need a new enough bios to support netboot to load the binary in the first place?

 

[DragonMinded]

It's possible because the NAOMI BIOS usually copies itself to 0x0C000000 (IIRC) and games reference this instead of the ROM location directly. The NAOMI header includes up to 8 chunks that say "copy this chunk of data to this memory address" so the HOTD2 netboot ROM uses this trick to include the mirror copy of the proto BIOS as if it was loaded by the system and the netdimm NAOMI BIOS dutifully overwrites what it just copied with the HOTD2 proto copy. It's the same theory behind SRAM restoration included in libnaomi and chunksin's wipi system.

 

[skate323k137]

Thanks, I really appreciate the explanation being documented concisely @DragonMinded

 

[MetalliC]

IIRC the BIOS is included in the netboot binary of HOTD2. It doesn't matter what BIOS is on the motherboard.

it's not that simple, but in general, in kinda this way I've did HOD2 netboot port

@DragonMinded hehe, and how do you think, is it possible for BIOS which is running in RAM to load whatever chunk of data in 0x0c00000-0x0c020000 area (i.e. HOD2 boot loader) on top of itself ?
spoiler: it's not
there was made special loader for HOD

there was also used another trick: when NAOMI BIOS trying to boot the game in 1st place it looking for NAOMI ROM header at 0x400000 in ROM/DIMM, if there is no heder was found it will look at offset 0
I've used this in HOT2 netboot, so it have IC22 at offset 0, and ROM HEADER + loader at 0x400000

and that's why you may simply copy&paste some another HOD2 IC22 dump in the beginning of netboot binary

Not saying I don't believe you or anything just the first thought that comes to mind.

are you OK man ? hard days or what ?

 

[skate323k137]

are you OK man ? hard days or what ?

Yeah man. Doing better now, had to change jobs recently but landed in a better spot. Hope you are well and thanks as always for the knowledge.

 

[PlatynumX]

@PlatynumX good work
but, if anyone have NAOMI 1/2 with NetDIMM and guns there is simpler way -
grab proto hod2 IC22 dump from MAME romset, grab netboot HOD2 binary, open them in HEX editor, copy proto IC22 contents and paste it at the very beginning of netboot binary
that's it, took few second to complete

Noted. I was debating going through the ic22 and see if I can't change the blood red/ enable the toggle from the u.s release. Knowing this will make this easier. Thanks for dropping the knowledge metallic.

 

[MetalliC]

as of regions - netboot binary have it hardcoded to US (2 byte patch, and it's the only changes which was made in IC22 dump)
if you'll "replace" it with proto IC22 dump - game will read region from DIP switches, like multi-bios.
nice side effect of how it works:
- game read region code from DIPSW
- game read region u32 value from BIOS area at 0x40000, and if it less than 5 - use this value as region code, otherwise ignore it
regular NAOMI bioses have some data/code at 0x40000, read value will be quite big, so, the game automagically will use DIPSW instead

 

[PlatynumX]

Just to follow up my attempts to swap the green blood files for the red ones result in a black screen in mame.
Interesting note : it appears the prototype ic22 has the full game files in it, has the normal test menu options(including the blood color toggle!)but disabled for some reason, and has English subtitles from every cutscene from the final game.

Also the scoreboard doesn't work!

 

[AlxUnderBase]

Great to read this

 

[PlatynumX]

i m about to give up on this red blood mod. I cant figure out why the game isnt liking what im trying to do it lol.(it worked in windows version back in the day)
anyways consolation prize :i used Metallic's lesson and made a netbootable copy of the prototype.
http://archive.org/details/hotd2p

 

[elrod]

i m about to give up on this red blood mod. I cant figure out why the game isnt liking what im trying to do it lol.(it worked in windows version back in the day)
anyways consolation prize :i used Metallic's lesson and made a netbootable copy of the prototype.
http://archive.org/details/hotd2p

Has anyone tried this outside of a cab? I have my Naomi2 connected to my projector and when i netboot this version the video does funny stuff like stretching the whole display to either the left or the right or duplicating the image. It's the only game where this happens.

 

[PlatynumX]

Let me see if I cant find a way to get out of cab and not use an old crt monitor or ossc. I think I have a more modern display around here that takes vga.

 

[PlatynumX]

well @elrod i was wrong. i dont have anything to test with. sorry

ive kept up trying to get red blood in this prototype and made a slight bit of progress. The secret to any censored version of hotd2 is swapping 2 file names around: scr_blood_red.bin and scr_blood_green.bin, easier on some platforms than others. i finally managed to accomplish this after reading through https://www.arcade-projects.com/threads/making-an-english-version-of-typing-of-the-dead-arcade.106/ i tried out a different hex editor recommended by @twistedsymphony in that thread. ive learned a lot from that thread really. ive made a little progress in that i can get the game to boot with absolutely no blood textures at all and the 'polygon rainbow' error typical of most games when a texture doesn't load properly for blood effects,bullet holes and skull fragment holes.

 

[MetalliC]

@PlatynumX why to so over complicate things ? in HoD2 proto you may simply
test switch -> NAOMI ASSIGNMENTS -> COUNTRY -> set to USA -> EXIT
GAME ASSIGNMENTS - BLOOD COLOR -> select RED or GREEN
that's it

 

[PlatynumX]

@MetalliC it's not there in the test menu to enable on the prototype on my end.Its in the ic22 but it's disabled.I don't have a multibios.im currently netbooting this on a Naomi with a Japanese bios. I think I misunderstood your post about how the bios is loaded and it hit me as I was typing this. Where's my duncehat? Lol

why to so over complicate things ?

It's more or less a test run to see if I can't swap out the script that ends the game and see if the full files are really there to look for more differences between this and release version.