Taken from the readme:
· Converted to Mapper 4: MMC3
· Mapper has been prepped (all mapper addresses written to at start-up)
· Expanded the ROM (double the size)
· Enabled SaveRAM (game saves your lives and completed stages/weapons after each stage, and when you get the special weapon)NOTE:
Unlike the Mega Man Upgrade Patch, this ROM has not been converted to CHR-ROM, and there is no option to erase saved game data. No text edits were made, no graphics were modified, no palettes were changed, and no levels were altered. The score is still intact, and no modifications were made to the original game engine at all. All that was added was mapper prep code, so that the game would run on real hardware, the save code, which loads and saves your progress, and the bankswitch routine, so that you could easily switch banks.
You may use this patch as a base for your Mega Man hacks. If you decide to use this for your hacks, credit is not necessary, but it is appreciated.End of readme text
This is more of a vanilla version of the Upgrade Patch. You'll have to use CHR-RAM, but there is still a lot of free space in the game, and working with MMC3 is very comfortable. Plus you have the added benefit of the game saving your progress for you.