Jump to content
NHL'94 Forums

help editing roms via hex editor


Recommended Posts

hi all,

i'm a beginner at this so there's probably a very simple and straightforward solution to this that is beyond me, but i just did some simple editing of players' names in a hex editor, saved the file and tried to open it in the gens emulator. all i got was a black screen. this isn't a case of me fooling with things that shouldnt be fooled with, because the same happens when all i change is one letter in someone's name or something of the like. i'd imagine i need to do something to fix the checksum or header of the new rom (i have no idea what these terms mean but i see them thrown around a lot), but i really dont know... can someone help me out and explain how i can prevent this? before you say "just use one of the rom editing programs," i'm attempting to edit other games which don't have editors released so this is an important problem for me to figure out.

thanks a lot

Link to comment
Share on other sites

hi all,

i'm a beginner at this so there's probably a very simple and straightforward solution to this that is beyond me, but i just did some simple editing of players' names in a hex editor, saved the file and tried to open it in the gens emulator. all i got was a black screen. this isn't a case of me fooling with things that shouldnt be fooled with, because the same happens when all i change is one letter in someone's name or something of the like. i'd imagine i need to do something to fix the checksum or header of the new rom (i have no idea what these terms mean but i see them thrown around a lot), but i really dont know... can someone help me out and explain how i can prevent this? before you say "just use one of the rom editing programs," i'm attempting to edit other games which don't have editors released so this is an important problem for me to figure out.

thanks a lot

http://en.wikipedia.org/wiki/Checksum

Near the end if the file, there is a checksum value that needs to be correct.

Link to comment
Share on other sites

sorry if this is another stupid question, but is there an easy way to make this become correct?

write a program that runs through the file and add up the values of the bytes, then re-writes the checksum. don't include the old checksum when calculating the new one

Link to comment
Share on other sites

Hint... Search the forums...

Hacking any other Genesis EA series games will be similar to the structure shown in the NHL series... other games from other developers/game consoles may have completely different data structures you will need to contend with...

Note, the EA games use their own checksum routine, and not the default one used by most Genesis ROMs... which Gens etc. ignore anyway (if it wrong) and still loadw the game.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...