Posted: 9/29/2004 3:03 AM
Post subject: What causes a "bad checksum"?
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Viewer
Joined: 6/4/2004
Posts: 284
Hello, everyone. A question that's been on my mind is this; what is it that causes different game ROMs, most often when a translation or other game affecting patch is used, to report a bad checksum in an emulator and thusly be unable to run? So far, very few patched ROMs have worked in Snes9x, while most of them have worked with ZSNES. However, some do not seem to work at all, even when released by trustworthy sources. Why is this? Does it have to do with the ROM itself--if so, could it be edited/worked around with a hex editor? Is the problem with the emulator? Please, somebody give some insight. Thank you.
Posted: 9/29/2004 3:52 AM
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Bag_of_Magic_Food
He/Him
Active player (278)
Joined: 5/29/2004
Posts: 5712
Well, uh, because the sum isn't the same anymore if you change enough bits. I guess some emulators can ignore it. And I suppose it's possible to edit things right if you know how the checksum is, well, summed. Yup.
put yourself in my rocketpack if that poochie is one outrageous dude
Posted: 10/3/2004 7:59 PM
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Bisqwit
Editor, Active player (296)
Joined: 3/8/2004
Posts: 7469
Location: Arzareth
Because updating the checksum to the ROM when creating a translation patch is troublesome, and not really necessary. I created a tool to do that in my Chrono Trigger translation, but it doesn't seem to always work ^^; Edit: I fixed the checksum problem in ctfin. But this is off-topic.