Can any NES/SNES game be hacked so as to include a save function?

[hamguy]

It has always bothered me that many NES and SNES games rely on passwords, or worse, have no save function at all. I would be interested in hacking games such as the NES/SNES Mega Man games, if I could add a save function and do away with the passwords. Would something like this be at all possible?

[Bregalad]

Not only it is possible but it has already be done.

However this is up to opinions, but the advantage of passwords is that you can note down many of them simultaneously without losing any of them, with saves usually this implies overwriting a previous save file.

[justin3009]

What Bregalad said.

Saving is definitely possible with any game as long as you have ROM space to code everything.  The only limitation you might have are the save game files.  SRAM is limited.  So games like Tales of Phantasia, which already allow saving, can only have up to three at once and no more unless SRAM is expanded (Which is doable, but the main debugger people use mirrors it incorrectly so it can't work, but it should run correctly if they're saved in the new space).

All it takes is a little bit of coding and figuring out what absolutely needs to be saved into the file.  Along with adding the menu and stuff of course, that's probably the hardest part out of the entire thing.

[Bregalad]

All it takes is a little bit of coding and figuring out what absolutely needs to be saved into the file.

Since the game already uses passwords, it would be simple to simply copy the password into the save RAM. Of course this is only one of the possible approaches.

[Grimlock]

A couple more hacks that add save capabilities:

Metroid + saving:

http://www.romhacking.net/hacks/1186/

Super Mario All Stars NES

http://www.romhacking.net/hacks/2422/