2600 Rom Comparisions and Dumps

[Rom Hunter]

Removed.

 

[Omegamatrix]

Just a quick note; work is progressing on My Golf. I have merged the two roms and found the differences. There is not a lot different, but there is significant changes (i.e. not something by error through bit rot or bad dumps). I am currently (and now almost completely) breaking down more of the data parts of the rom to get a better understanding of what is being done, and where. I ususally do it this way when disassembling as it makes the rest of the rom much easier to read. It is far easier to tackle the ram allocations after this, and it seems that is what needs to be done!

 

Ram $99 is going to be key in understanding why the changes were made. At this point I'm not even sure what is the original and alternate. Better written I'm not sure at this point what rom came first, and what came second. It'll become clearer as more is disassembled. I do need a couple of more days though.

 

 

 

As a secondary note I will soon be adding a list to the first post of this thread. It will contain a list of games yet undumped. This is meant to be a list of ordinary games that for some reason or other have been overlooked in dumping. Such a list could include:

 

- Playaround double enders that have only been dumped as a single Mystique ender. These likely only have the Mystique logo swapped for. That's it.

- Secam Activision carts. They have French writing on the screen.

- Lots and lots of PAL carts.

 

 

Rom, if you could make me a list I'd appreciate it. I'm not looking for prototypes here, those belong in another thread. This is more like Challenge of Nexar or Bridge. Not something no one owns like a Monogrammed SpaceChase.

[Rom Hunter]

Was already working on it.

 

Thanks, Omega!

 

 

Not something no one owns like a Monogrammed SpaceChase.

Don't be too sure about that...

 

[John Saeger]

Dear Rom.

 

I think what you're doing with the "classic" Atari 2600 ROMS is really great! I like the idea of an emulator getting its parameters from the filename. I've done a "play-through" of your collection and I thought I'd bring up the idea of changing the colors of the following ROMs, that is to reverse PAL and NTSC for the following games:

 

Air Raid (Men-A-Vision) (PAL).bin

Artillery Duel (1983) (Xonox - K-Tel Software, John Perkins) (6230, 7210, 06004, 99004) (PAL).bin

Artillery Duel (1983) (Xonox - K-Tel Software, John Perkins) (6230, 7210, 06004, 99004) (PAL) [a].bin

Asteroid Fire (1983) (Home Vision - Gem International Corp.) (VCS83111) (PAL).bin

Bermuda (AKA River Raid) (Unknown) (PAL).bin

Boom Bang (AKA Crackpots) (1983) (CCE) (C-849).bin

Chopper Command (Hack) (2600 Screen Search Console) (Jone Yuan Telephonic Enterprise Co).bin

Dungeon (Dark Chambers Beta) (1985) (Atari, John Howard Palevich) (CX26151, CX26151P) (PAL).bin

Frog Demo (1983) (CommaVid, Joseph Biel).bin

Great Escape (AKA Asteroid Fire) (1983) (Bomb - Onbase) (CA282) (PAL) [a].bin

Karate (Unknown) (PAL).bin

X'Mission (1983) (Home Vision - Gem International Corp.) (VCS83118) (PAL).bin

 

I think Air Raid has already been discussed somewhere, looks better in NTSC.

The Artillery Dual games are only 259 scanlines and look great in NTSC.

Asteroid Fire and Great Escape are badly positioned for PAL games.

Bermuda is not well positioned as a PAL game and looks great in NTSC.

Changing Boom Bang is perhaps controversial since it only has 268 scanlines but the colors are better in PAL.

Likewise changing the Chopper Command Hack is controversial as it only has 271 scanlines, but in PAL, the water is blue.

Dungeon, yah well, no biggie, but nonetheless, the grass is green in NTSC.

Frog Demo has 297 scanlines and is better positioned in PAL.

Even though Karate has 302 scanlines, it's better positioned in NTSC.

X'Mission is better positioned as NTSC.

 

Of course if you have other data supporting your original choice, like you dumped the rom from a cart that was in a box labeled PAL, I suppose we should go with your original choices. Otherwise, I guess my point is that the number of scanlines in a game is not necessarily the decisive factor in deciding how to make it look best. The colors and where on the display the game shows up are also important.

 

Thanks and keep up the good work!

 

John

[Rom Hunter]

Dear John,

 

Thanks for your warm reply.

 

If it's only a matter of programming Z26 to show the ROMs correctly, then I can fully understand your idea of displaying the games in the best possible way, while playing them on an emulator.

 

But if the ROMs themselves are being changed, I'm strongly against this idea.

 

I prefer the .bins to be 100% identical to the real thing, without any changes to their contents.

 

BTW: Dungeon and Frog Demo have been renamed a few moths ago:

 

Dungeon (Dark Chambers Beta) (11-22-1985) (Atari, John Howard Palevich) (CX26151, CX26151P) (Prototype)

(after all: 285 scanlines is in the NTSC range as well)

 

Frog Demo (1983) (CommaVid, Joseph Biel) (PAL)

 

Edited December 19, 2008 by Rom Hunter

[Shawn]

Not something no one owns like a Monogrammed SpaceChase.

 

How many do you want?

[Rom Hunter]

Rom, if you could make me a list I'd appreciate it. I'm not looking for prototypes here, those belong in another thread. This is more like Challenge of Nexar or Bridge.

Ok, let's start with the first four important companies.

 

Missing ROMs:

 

20th Century Fox:

 

M*A*S*H (PAL):

http://www.atarimania.com/detail_soft.php?...ERSION_ID=12265

 

Turmoil (PAL):

http://www.atarimania.com/detail_soft.php?...ERSION_ID=19324

 

 

Activision:

 

Decathlon (SECAM):

http://www.atarimania.com/detail_soft.php?...ERSION_ID=14009

 

Bridge (PAL):

http://www.atarimania.com/detail_soft.php?...ERSION_ID=13465

 

H.E.R.O. (SECAM):

http://www.atarimania.com/detail_soft.php?...ERSION_ID=19482

 

Keystone Kapers (SECAM):

http://www.atarimania.com/detail_soft.php?...ERSION_ID=19483

 

River Raid (SECAM)

http://www.atarimania.com/detail_soft.php?...ERSION_ID=19529

 

Space Shuttle (SECAM):

http://www.atarimania.com/detail_soft.php?...ERSION_ID=19855

 

 

Apollo:

 

Shark Attack (PAL):

http://www.atarimania.com/detail_soft.php?...ERSION_ID=13541

 

Spacechase (PAL):

http://www.atarimania.com/detail_soft.php?...VERSION_ID=8307

 

 

Atari:

 

16 in 1 Game Cartridge:

http://www.atarimania.com/detail_soft.php?...ERSION_ID=13733

 

Signal Tracing Cartridge:

http://www.atarimania.com/detail_soft.php?...ERSION_ID=18655

 

 

If anyone can dump any of the carts above, please let me know.

 

Edited December 19, 2008 by Rom Hunter

[Omegamatrix]

Rom, just PM me a list and I'll add it to the first post of this thread. I'll add these carts to it in the meantime.

[+Mitch]

The signal tracing cart doesn't have a ROM that you can dump, it's just a bunch of resistors and caps on a cart board.

 

Mitch

[Omegamatrix]

The signal tracing cart doesn't have a ROM that you can dump, it's just a bunch of resistors and caps on a cart board.

 

Mitch

Good to know. Okay the first post in this thread is now a list of undumped games. I'll keep adding to it as I think of carts or you guys tell me.

 

 

 

 

@ Shawn

Lol, I'll take them all! but wait, isn't this something I could do with Bithacker in about 30 seconds? I reduce my tender offer from $2500 to 3 food stamps.

[Rom Hunter]

Omega,

 

PM sent.

 

 

Thanks for the info, Mitch.

 

[Rom Hunter]

List on post #1 is looking good, Omega.

 

Let's hope some collectors will take the effort to dump one of these carts.

 

Perhaps it's a good idea to rename the topic as well.

 

[Omegamatrix]

List on post #1 is looking good, Omega.

 

Let's hope some collectors will take the effort to dump one of these carts.

 

Perhaps it's a good idea to rename the topic as well.

 

It's starting to come together. It is already a very long list. I spending a great deal of effort to not overwhelm a person when they see it. The embedded links and italics help to that end, I think.

 

 

I really hope no one copies the whole list with a "I got 1 of these do u want to dump it thaks", because we'll be scrolling down the page forever.

 

 

I'll think about renaming the thread. The original idea (and still is the main idea) of this thread is the discussion of differences between Atari 2600 roms. To that end it has been somewhat successful. Its first and foremost purpose is discussing the exact differences between the games. If it is a fixed rom, what was fixed? If it is an alternative rom, why exactly is different about it? New rom dumps do go in hand with this thread, but aren't the primary purpose.

 

 

 

Well I got to get back to work on the list. This has completely sidetracked me from My Golf, but well worth it.

Edited December 20, 2008 by Omegamatrix

[Rom Hunter]

Omega,

 

I think the list is long enough for now.

 

It will take years to tag.

 

Perhaps we could ask Jason from AtariGuide if he can dump one of these carts.

 

 

If you want to take a closer look at the last five ROMs from post #642, I will appreciate it very much.

 

Next week, my V4 collection will go online.

 

 

BTW: it's Goliath, not Golitath.

 

Edited December 20, 2008 by Rom Hunter

[Omegamatrix]

BTW: it's Goliath, not Golitath.

Fixed! BTW the My Golf is also a fix. There is a branch taken before an index register is updated to load a series of registers. The alternative corrects this and does a few other minor corrections. I don't have time to look at the other roms though. Lots of friends and family going on right now!

 

 

I shortened the list a bit. I think its addition by subtraction. With all these pirates the some of the original titles get buried. For instance Pete Rose Baseball (PAL) wasn't on that list you gave me, but really should be dumped over four or five versions of Sea Monster? These Goliath roms, what do you know is different about them?

[Rom Hunter]

Would like to find that out too.

 

Thanks for the My Golf info.

 

[Omegamatrix]

No worries about My Golf. Just remember although everything I've seen goes along with a fix right now, there are still large parts of the rom not disassembled. I think you have to enjoy pain to do this. Sometimes it's very simple and clear and other times its like chewing nails, whatever that is like. When you finally break down a chunk of it the Ah Ha is very rewarding, but nothing beats the point when you got it almost all the data and ram locations mapped out. It sort of avalanches and reads like a book. I'm making my way along though.

 

 

 

Anyhow Rom if you can think of anymore good entries I'll add them to the list. I look at the PAL list and there is a few surprising ones on there like Bridge, Stronghold, Pete Rose Baseball, etc... that for some reason or other have never been dumped. LMK!!

[Rom Hunter]

Omega, Thomas or Nukey,

 

If you find the time to have a look at Super Breakout and Racquetball (post #642) before thursday, I would very much appreciate it.

 

The only thing I would like to know is:

 

Which version is the original version?

 

Is the other version truly a fix or not?

 

Edited December 22, 2008 by Rom Hunter

[Sysbase]

This is awesome thanks!

[Rom Hunter]

What exactly is the diffrence between these two:

Centipede__1982___Atari___GCC___CX2676___PAL_.bin

Centipede__1982___Atari___GCC___CX2676___Prototype___PAL_.bin

 

[Impaler_26]

What exactly is the diffrence between these two:

Centipede__1982___Atari___GCC___CX2676___PAL_.bin

Centipede__1982___Atari___GCC___CX2676___Prototype___PAL_.bin

 

I just compared the 2 roms with HOM 3 and there are only 2 differences between them, at $0FF9 and at $1FF8.

[Rom Hunter]

Thanks!

 

[Nukey Shay]

Omega, Thomas or Nukey,

 

If you find the time to have a look at Super Breakout and Racquetball (post #642) before thursday, I would very much appreciate it.

 

The only thing I would like to know is:

 

Which version is the original version?

 

Is the other version truly a fix or not?

 

Since the non-alternate files match the released games (verified good dumps), it's pretty conclusive that the [a]lternate files didn't have these bugfixes in place - and are likely to be earlier versions. I wouldn't be able to tell you more than that without reverse-engineering the games to know what the upper boundries of these variables are supposed to be (and I got a bit lost looking at both of them).

[Omegamatrix]

It's a new year, and that means new roms! Dino has once again helped with some of the rarest of rare. I just crossed off Time Warp and Custer's Revenge from the list on the first post of this thread.

 

 

NewPALroms.zip

 

 

Inside are a couple of sand paper rough disassemblies comparing the new roms to their NTSC counterparts.

 

Time Warp has that beautiful Funvision logo on the bottom of the screen, while the Zellers version has the logo erased. The Zellers version will therefore draws "nothing", so you wouldn't even know a logo is supposed to be there without taking a peek inside a rom. This is a very common way for pirate companies to hide a logo. Erase it, and leave the routine that draws it untouched. Very easy to do.

 

It has some of the usual changes we see between NTSC and PAL versions:

- changes in the length time for Vblank and Overscan

- more scanlines added directly into the kernel

- color changes (to correct for the different palettes)

 

Time Warp also has some interesting broken code. This code is splices of routines used else where in the game. It absolutely belongs to the game as it is completely the same, but spliced so it might start between an instruction and the operand, and not quite finish. I can only guess that this somehow happened while reusing a eprom during the build process.

 

 

Custer's Revenge is very interesting in that they changed colors for a PAL conversion, starting adding more scanlines, and then fell short. The original NTSC rom has 258 scanlines. The PAL only has 264 scanlines. So the original NTSC one is a little too short, and the PAL one is way too short. We've seen this before; PAL Artillery Duel springs to mind, where they failed to adjust the scanlines correctly.

 

None the less it comes from a verified PAL cart, so I lableled the rom:

 

Custer's Revenge (Mystique) [verified PAL cart, but only 264 scanlines] (PAL).bin

 

To me that avoids any confusion as I know that it is from a PAL cart. If you have no explanation in there you loose the source. I like to know where my roms come from.

[Rom Hunter]

Added.

 

Thanks, Omega & Dino!

 

 

Nukey,

 

Thanks for the info.