Mortal Kombat Madness?
Posted: Sun Apr 17, 2016 9:35 pm
So, I'm doing a bit of bug hunting in my GB emulator, and I figured I should start off with some problems affecting specific DMG games. I thought Mortal Kombat & Mortal Kombat II would be simple enough as a starting point, but it turns out this isn't the case. Allow me to explain.
This game is a compilation of the 1st and 2nd MK games for the DMG, so it uses a menu after the copyright and publisher info screens. Selecting either MK1 or MK2 from the menu, however, always restarts the game back to the copyright and publisher screens. Start, Select, A, B, doesn't matter what's pressed; the result is the same, just an endless loop without the game starting.
Now, at first, I dismissed this (the issue was reported to my project) as a bad dump, but when I checked with another source, the dump they used was clean (as far as the MD5 hash indicates) and it exhibited the same problems in my emulator, in BGB, and in VBA-M. What's even stranger is that they put MK & MKII on a flashcart and played it on a real Game Boy, only to have the same menu-loop problem occur on real hardware. My next thoughts were that maybe no one has been able to get a clean & verified dump of this game before (unlikely, but hey, it could happen).
Unfortunately, I don't think that's the case. I stumbled upon this ebay page as I was looking to buy this game myself. So, looks like actual production carts had bugs in them too. Evidently, this isn't an issue of emulation or getting complete ROM data from the physical cart; it seems like something larger...
So here are my current thoughts:
1) Maybe they goofed when making a number of MK & MKII carts. A number of them might have defects that make the game unplayable.
2) Maybe they aren't really using an MBC1, maybe something different that neither flashcarts nor emulators can handle? But that doesn't explain why commercial carts have the issue, unless something inside the cart breaks down over time. But how would that affect dumping it properly?
3) Maybe something inside the cart is defective (something to do with the MBC itself) but the ROM image is still usable, e.g. the ROM banks need to be rearranged after using a dumping tool?
Any thoughts from others are appreciated. If you know anything about this game, let me know. Thanks everyone
This game is a compilation of the 1st and 2nd MK games for the DMG, so it uses a menu after the copyright and publisher info screens. Selecting either MK1 or MK2 from the menu, however, always restarts the game back to the copyright and publisher screens. Start, Select, A, B, doesn't matter what's pressed; the result is the same, just an endless loop without the game starting.
Now, at first, I dismissed this (the issue was reported to my project) as a bad dump, but when I checked with another source, the dump they used was clean (as far as the MD5 hash indicates) and it exhibited the same problems in my emulator, in BGB, and in VBA-M. What's even stranger is that they put MK & MKII on a flashcart and played it on a real Game Boy, only to have the same menu-loop problem occur on real hardware. My next thoughts were that maybe no one has been able to get a clean & verified dump of this game before (unlikely, but hey, it could happen).
Unfortunately, I don't think that's the case. I stumbled upon this ebay page as I was looking to buy this game myself. So, looks like actual production carts had bugs in them too. Evidently, this isn't an issue of emulation or getting complete ROM data from the physical cart; it seems like something larger...
So here are my current thoughts:
1) Maybe they goofed when making a number of MK & MKII carts. A number of them might have defects that make the game unplayable.
2) Maybe they aren't really using an MBC1, maybe something different that neither flashcarts nor emulators can handle? But that doesn't explain why commercial carts have the issue, unless something inside the cart breaks down over time. But how would that affect dumping it properly?
3) Maybe something inside the cart is defective (something to do with the MBC itself) but the ROM image is still usable, e.g. the ROM banks need to be rearranged after using a dumping tool?
Any thoughts from others are appreciated. If you know anything about this game, let me know. Thanks everyone