How to Insert Custom ROMs into Sonic Mega Collection

Out of pure curiosity, I tried to find a way to replace a ROM in Sonic Mega Collection with one of your choosing. Here's that way.

NOTE: This tutorial does NOT work with the PC version to my knowledge. Only with the Gamecube, Xbox, and PS2 versions.

All you'll need to do this is:

• An .iso or whatever of Sonic Mega Collection.
• An emulator to run the .iso
• HxD (You may have another hex editor, but you still need to get this, as it is needed to edit RAM.)

To start, open up your emulator of choice and load up Sonic Mega Collection (or Sonic Mega Collection+, for those using the PS2 version like me)

Now, open HxD and go to the Open RAM option at the top. It looks like this:



A list should of the current running programs should then pop up. Look for your emulator on said list, and double click it. All you need to do now is search for something in the header. For example, I searched for 'SONIC THE'.



Just scroll up a little bit to find the beginning of the ROM. Look at what offset it's at, and keep it in mind. Click 'Edit' in the top bar, and then click the 'Select block...' option, like so:



A window should now pop up. Make sure the starting offset is the same as the beginning of the ROM's offset. Click the 'Length' bubble and change the value under it to however long the ROM is supposed to be (shocking, I know). In this case, Sonic 2 is 100000 bytes long, so the window would look something like this:



Just click 'OK', and the whole ROM will be selected. From here, all you have to do is copy the ROM you wish to inject (using a hex editor of course) and paste it into place. Make sure to click 'Save' before you do anything else. Once all of that is done, go back to the emulator, and select the 'Game Title' option from the menu. This will reset the game, and should (hopefully) run your injected ROM!



Keep in mind that the Genesis emulator used in Sonic Mega Collection has terrible sound emulation, and I have no idea what games wouldn't run on it. That's for you to find out.

Happy injecting!

 

Interesting! I'll grab my Sonic Mega Collection Plus (for PC) and see if I can produce similar results.

 

Big bump here; from May to August. Ooh, very interesting. I'll experiment with that once I can get a working emulator for PS2 to start, since that's what I'm planning on using.

 

You bumped the topic just to say you're going to give it a go sometime?  That's unacceptable.  I would have been fine if you bumped it to say there was an issue and you were asking for help, but not this.