Back in the days of the GBA there were a fair few hacks for roms for other systems intended for use in emulators. Now the DS has some decent emulation of other systems (in as much as the games are by and large playable, I can forgive lack of cheats) I thought I would see if there is any interest in the area. There was a site called GBAfan that had a fair few of these for the nes and SNES but it is long gone and I do not know of any mirrors. Good news is that hacking tools, hacking grade emulators, hardware documentation, hacking guides and those knowledgeable in it are far more plentiful for older systems than there are for the likes of the DS. The only bad thing I can see is that a sizable chunk of the tools available are dos based which can cause headaches for those on newer systems as guides tend to be written for them (and the people who wrote either vanish or stick around but as they see the updates as incremental there is "no need" to update the guide). The guides are not usually tailored specifically for this but hacking a font for a translation is exactly the same as hacking a font to make it look nice on an emulator. Romhacking.net is naturally the place to start for info on systems if you want to have a go. My main machine is still down so I am doing much hacking at the moment but I am willing to lend a hand if I can. Possible hacks include font hacks: GBA emulation tended to shrink tiles to deal with resolution issues which meant some fonts looked horrible (try playing the final fantasy 3 (Japanese naming) fan translations on pocketnes: in this example the font is uncompressed nes format and you also have HVCA but others are not so lucky). Fonts were either shrunk or reworked to deal with this and make the game playable. Similarly the GBA and DS gave a fairly small screen compared to TVs which the games are designed for so "easy read" hacks are possible. OAM hacks: I am thinking mainly about newer jenesis versions here that lack horizontal scaling. In game menus are typically on the left of the screen and are often cut off now there is no horizontal scaling. Simply put the OAM (whether a distinct memory section or part of the main block) is what controls where things are on the screen. It is not however usually that difficult to alter both the OAM itself (you can do it with cheats even) and the code behind it (20 minutes on a tracing emulator and given you can even hardcode those these days with stuff like cracker's GGGP). Improvement hacks: normally associated with stuff like high res texture replacement for the N64 but can be stuff like palette switching to improve colours: games designers know a lot of tricks to make things look nicer than you would think the hardware would allow (try going slow on a late PS1 era wipeout game). Unfortunately a lot of these tricks can fall short on a small LCD or as was the case in early GBA the LCD was quite dark. Control hacks: the DS/GBA are different to the controls on something like the megadrive: 6 button megadrive X is normally mapped to L which is quite different to the official 6 button controller. Speed hacks: these can be anything from removing limiters to recoding sections of the game to run faster (normally at a cost to sound or appearance but simple optimisation is possible too). Also in this is hacks for roms to get them to run in emulators, frowned on to some extent by some in the community as it can affect the course of emulator development and the like but given the choice between replaying a great game from my youth or maybe annoying someone I have never met (and probably never will) over what amounts to a trivial matter I know which one I would pick. Older systems tended not to have stuff like the boktai solar sensors but I am including that there too.