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2600 Rom Comparisions and Dumps


Omegamatrix

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Is there a date on the label?

 

8)

 

 

 

The label says it's 3/18 release, but the binary dump differs a lot from the final version. The melody is different (one more note in the beginning) and the game logic part is also different.

 

similarity between released and proto dump 0.934, levenshtein distance: 538 (so 538 single changes to the Proto file would be needed to be identifcal to the release version).

 

 

Andre

 

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One ROM less, seven to go.

We still need the following third party PAL ROMs (the red ones are PAL originals, not hacks or conversions):


- Coco Nuts (Telesys)

- Plate Mania (Home Vision)
- Stargunner (Telesys)
- Stronghold (CommaVid)
- Topy (Home Vision)
- Treasure Discovery (Home Vision)
- X’Mission (Home Vision)

8)

Edited by Rom Hunter
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  • 5 weeks later...

I've long suspected the HES version of Robot Tank would be different, and sure enough it was.

 

RobotTank(AllVerisions).zip

 

I've included a disassembly that can compile all versions of Robot Tank. The dump is good, but if you fire this up in Stella it will incorrectly auto-detect the rom as FE. You need to manually configure the game properties so that the type is F8 (8K Atari).

 

Now the only question is if there is an NTSC F8 version of Robot Tank out there, and undumped. I feel that there is a good chance there is.

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The dump is good, but if you fire this up in Stella it will incorrectly auto-detect the rom as FE. You need to manually configure the game properties so that the type is F8 (8K Atari).

 

I'm fixing the autodetection in Stella right now for such a case. Just making sure it doesn't cause anything else to fail detection.

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I've started dumping some of the unusual carts in my collection, and so far almost all of them are identical to known good ROMs according to CloneSpy. I've attached one that isn't an exact match with the ROM in the Atarimania V15.0 collection -- it's an early/review copy of Gangster Alley, as seen in my Twitter post here (it has a generic Spectravision end label, and weighs a slight bit more than a "regular" Gangster Alley cart).

 

I disassembled both my dump and the standard Gangster Alley ROM, and in comparing them I can see that they aren't exactly the same, but I don't really know enough about assembly language to know whether the (very minor, I think?) differences are of any significance. I don't immediately notice any difference in the gameplay or graphics, but it's also possible that I'm missing something obvious. It could also just be a bad dump, of course.

 

Would love if someone could let me know!

Gangster Alley (review copy).bin

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Their released version has a few bug fixes (e.g. several missing # got fixed, a missing branch got added), but no other changes. So this is probably a very late beta version before the final release.

Edited by Thomas Jentzsch
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Thomas, thanks for confirming that my Gangster Alley dump is a pre-final ROM! Very cool.

 

Rom, I don't have any of the undumped PAL titles, unfortunately.

 

Attached are three more that may be unique.

 

- From eyeballing the code of Sea Hawk (Home Video Computor Games) and comparing it, it seems to be identical to the PAL Sancho ROM except it has the on-screen "©Sancho 1982." graphics blacked out with $00.

- I could only get Yars' Attack to dump by using an 8K setting in MaxFlash Studio. I would guess it's just the standard 4K PAL Yars' Revenge on an 8K ROM (i.e. Bank 0 looks like it might be empty?)

- Mr. Gobler seems to be the same as the standard NTSC Pac-Man, with the on-screen Atari copyright blacked out in the same manner as the Sea Hawk ROM.

 

Confirmation/refutation of my analysis is welcome. More to come.

Sea Hawk (Home Video Computor Games).bin

Yars' Attack.bin

Mr. Gobler.bin

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If you split the Yar's rom in half and throw away bank 0, then you will find the exact PAL version there so this dump as 8K is bad. With Sea Hawk (PAL) the logo is erased. Also, the last byte of the rom is changed from $00 to $FB. That byte looks unused. Mr Gobler is NTSC Pac-Man with the logo erased.

 

 

 

I did a comparative disassembly of the Gangster Alley review cart.

 

GangsterAlley(NTSC).zip

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If you split the Yar's rom in half and throw away bank 0, then you will find the exact PAL version there so this dump as 8K is bad. With Sea Hawk (PAL) the logo is erased. Also, the last byte of the rom is changed from $00 to $FB. That byte looks unused. Mr Gobler is NTSC Pac-Man with the logo erased.

 

 

 

I did a comparative disassembly of the Gangster Alley review cart.

 

attachicon.gifGangsterAlley(NTSC).zip

 

Thanks so much, Omegamatrix.

 

How does one split ROMs? The smallest setting that Maxflash Studio offers for dumping is 4K, but there are a few 2K games that I was forced to dump with the 4K setting. Similarly, I have some 8K and larger ROMs that I'd like to use distella to look at more closely, but of course it only can handle 4K at a time, AFAIK.

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Thanks so much, Omegamatrix.

 

How does one split ROMs? The smallest setting that Maxflash Studio offers for dumping is 4K, but there are a few 2K games that I was forced to dump with the 4K setting. Similarly, I have some 8K and larger ROMs that I'd like to use distella to look at more closely, but of course it only can handle 4K at a time, AFAIK.

There's various utilities, or you can even use the command line.

 

I usually use HOM3.

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This is where it gets interesting. :) The PAL Gameworld rom also has $08 at $FF40.

 

I didn't look what this byte is for, but it makes me wonder if $0A is actually the correct value. A 1 bit difference is suspectable. At this point I would really like it if a retail copy NTSC Warplock was dumped to see what we find.

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I did a comparative disassembly of the Gangster Alley review cart.

 

attachicon.gifGangsterAlley(NTSC).zip

Thanks for the comparison code.

 

I found that they swapped the scoring between Mugsy ($20..) and Scar Face ($30..). Probably because Mugsy is an easier target. And they decreased the time before they draw the gun (UNKNOWN_01) by 33%. So the final release is harder than the review copy,

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At this point I would really like it if a retail copy NTSC Warplock was dumped to see what we find.

 

Done. My dump of the NTSC retail cart matched my sample Warplock cart dump 100%, so I'm attaching it here.

 

And just so a one-useless(?)-byte correction of one of the worst games on the system isn't the sole content of this post :) , I'm also including my dump of a sample/review copy of Beany Bopper. The only difference (pretty sure) between it and the standard release:

 

post-43608-0-06450300-1550440323_thumb.png

 

I dumped a Deadly Duck sample/review cart as well, but it matches the final release. Up next to dump and compare: review copies of Trick Shot and Star Voyager.

Warplock (NTSC).bin

Beany Bopper (review cart).bin

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Thanks for the confirmation with Warplock. Based on your both of your dumps being the same I am going to recommend that this NTSC dump of Warplock be marked as the good rom. The one that is currently in Rom Hunters collection should be marked as a bad dump because we can't source where it came from. While it could possibly be an alternate I would say that it is a very low probabilty. It is much more likely to be a bad dump and it should be replaced with yours. Thank you for your help in finding this. Well done! :)

 

 

With Beany Bopper that new rom does not look good. The instructions make no sense because one byte is corrupted.

 

DEC (%11000110) got changed to SEI (%01111000). The arguement of DEC is $81 which is the opcode for STA indirect X. Anyhow the next few instructions changed simply because of that one byte being different.

;old
    dec $81     ; $C6,$81
    ldx #$00    ; $A2,$00
    
;new (DEC changed to SEI)
    sei         ; $79
    sta ($A2,X) ; $81,$A2
    brk         ; $00
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Done. My dump of the NTSC retail cart matched my sample Warplock cart dump 100%, so I'm attaching it here.

 

And just so a one-useless(?)-byte correction of one of the worst games on the system isn't the sole content of this post icon_smile.gif

That different byte is not used by the code at all.

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