midway arcade greatest hits mod?

[SMiTH]

deluxux brought this up a few weeks ago as an idea, and I have also thought about this mod in the past as well.
The midway arcade hits games for dreamcast could possibly be modded?
I think on the og xbox there was a mod for the midway games that added custom roms.
From what I remember they had to overwrite the rom data using hex data, it wasn't a rom swap.
I could be wrong but the roms used had to be smaller in size or exact due to using hex data?
(to not go over the size of the original roms)

I looked at the midway games for dc and never figured it out.

Maybe search the dc files for similar hex data to the original game roms used on the disc?
(compare each mame game rom hex data to dc files etc)
I tried this but, didn't put much time into it.

mame roms have many files in a zip from what i remember??
the data could use different endianness or maybe encrypted as well??
Has anyone tried to mod the game?

Lou_P had some info on what games might be compatible.

Midway arcade classics vol. 1 and vol. 2 are likely a emulators of the following boards.

Vol .1
board
WILLIAMS 6809 REV.1
Bubbles
Defender
Joust
Robotron
Sinistar
Defender II / Stargate

Compatible games:
https://www.system16.com/hardware.php?i ... =1044#1044

Vol. 2
Boards
Irem M-52 (moon patrol)
Compatible games
https://www.system16.com/hardware.php?id=736
Atari System 2 (paperboy and 720)
Compatible games
https://www.system16.com/hardware.php?id=769
Bally Midway MCR-Scroll (Spy Hunter)
Compatible games
https://www.system16.com/hardware.php?id=605
Atari Gauntlet (Gauntlet)
Compatible games
https://www.system16.com/hardware.php?id=766
Midway MCR-III (Rampage)
Compatible games:
https://www.system16.com/hardware.php?id=602

Just are early 80's games.
Just a little bit of information to someone could have this modding challenge

[SMiTH]

I found a few interesting things about midway 1.
Turns out what I thought was a mod on og xbox for midway games was not really a mod at all.
It was just game files that were unlockables on different disks and making a standalone.
None of it was for the midway games.

As for midway 1.
It is a wince game.
You can overwrite the data for roms.
The mame rom files are in plain hex.
I was correct about this being the case.
But, it leaves 2 unused mame rom files (unless this data is somewhere else or scrambled/encrypted)?

When overwriting the mame rom data the game does not crash.
I think this might be good because typically doing that would crash a game.
So I'm thinking that it has to do with those 2 files and possibly a line of hex code before the rom is loaded?
This line of hex code looks like what I have seen in save files that usually is encryption? (just guessing)
Either way it still is interesting.

As for midway 2 its totally different.
It is not a wince game.
The file structure is different.
I have yet to really delve deeper.

I will post stuff about the findings later.

[SMiTH]

MIDWAY_1.EXE AND BUBBLES mame game rom:
The exe has the plain hex code for the game rom. (in this example bubbles.1b - bubbles.12b)
It represents bubbles.1b - bubbles.12b in the mame game rom archive.
In MIDWAY_1.EXE - start bubbles.1b @ 000b39c0
In MIDWAY_1.EXE - end bubbles.12b @ 000bfdc0

The 2 mame game rom files that are maybe scrambled/enc or elsewhere in the dc data are:
decoder.4
decoder.6

The sound data is in a .dat file for the dc : BUBSND.DAT
It is bubbles.snd in the mame rom archive.

Possible enc?? MIDWAY_1.EXE (hex code before bubbles game rom data) just guessing here??


I replaced the game bubbles with mame game rom splat!
Once at game selection screen after choosing bubbles game...
The game doesn't load.
I thought it freezes, but it doesn't.
No crash happens either.
So, I'm thinking its possible to figure this out?