Author Topic: A few Genesis games not reading  (Read 2238 times)

Offline KingMike

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A few Genesis games not reading
« on: 05/Dec/2013 06:09:42 AM »
Just got mine, great so far.

I was going through my collection of Genesis games and noticed a few of them will not read, even though I have cleaned them. I checked and they booted just fine on my actual hardware (US model 2 Genesis).
Results in Kega Fusion:
Batman (The (original) Video Game) (US) - black screen with screeching noises. I check the ROM and the header looks normal.
Zero Wing (Japan) - plays intro without sound, when trying to start gameplay freezes on a black screen with only the HUD visible
Sorceror's Kingdom (US) - black screen, glitch title in header. From opening the dump in a hex editor and looking at the header, it looks the ROM is somehow interleaving itself

And a few with bad checksums but still play. Unsure if normal:
MegaPanel (Japan)
US: Dynamite Headdy, Lightening Force, The Flintstones

Offline Matthias_H

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Re: A few Genesis games not reading
« Reply #1 on: 05/Dec/2013 09:40:59 PM »
Hi Mike,

If you send me the dumps, I can have a look and see if I can find something obvious. support at retrode dot org

Cheers,
Matthias
http://www.retrode.org

I no longer sell the Retrode. For sales inquiries, please contact our friends at DragonBox.

Offline KingMike

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Re: A few Genesis games not reading
« Reply #2 on: 03/Jul/2014 04:55:07 AM »
I don't know what's going on with Batman or Sorcerer but I see the problem with Zero Wing is that the game has a bad header. It says 4mb but according to Internet dumps it should be 8mb.
(Batman, I think Matthias must've pointed it out in the email but it looks like D7 is constantly 0. Not sure why the game doesn't break on console, though.)
Indeed Zero Wing does have a wrong header. Forcing the system to mdrv and size to 8 fixes it.
My copy of FireShark (USA) dumps with a bad checksum but seems to only differ from the Internet dump by a single block of ~$70 bytes (address $D886-D8EB all zeroed, if anybody wants to actually play the game and figure out what it does). I wonder if it could possibly be a revision, as that seems to be an awful small and specific set of data to just be a dumping error.

I have several other games with checksum errors but seem to all match scene dump hashes, so maybe that's normal then.
« Last Edit: 03/Jul/2014 05:19:14 AM by KingMike »

Offline Zerker

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Re: A few Genesis games not reading
« Reply #3 on: 05/Jul/2014 01:30:57 PM »
KingMike, I would clean and try dumping Lightening Force again. The checksum matched for mine.

My Fire Shark checksum doesn't match either, and it appears to have the same zero block as yours. My MD5Sum is C00981929F3ECA882D123809E81185DF if you want to compare. When I google search this particular MD5 sum, I do see a few pages listing it as good dump of the game.

Also, I hacked up a Python 3 script a while ago to dump out a CSV listing for Genesis roms. It will list the contents of the headers, as well as automatically perform standard checksum algorithms on the files. This may be useful:

www.zerker.ca/zzone/files/geninfo.py

And the output for my collection as an example:

www.zerker.ca/zzone/files/genesis_rominfo.csv
« Last Edit: 05/Jul/2014 01:37:05 PM by Zerker »