3DS:Virtual Console

A Virtual Console (VC) is an official way that Nintendo has provided to play versions of older games on the 3DS. These VC games appear as individual icons on the HOME Menu. Most of these VCs leverage Nintendo-made emulators, and some of them offer additional functionality like savestates, fast-forward, or perfect-pixel mode (playing at the game's original aspect ratio, with blur removed).

Creating VC injects
Using the software NSUI, you can 'inject' a legitimate rom from most consoles into a Virtual Console game. At current, see the linked page for more specific instructions on using NSUI. Later on, a creation page will be made.

Extracting VC games
Using GodMode9, you can extract the ROMs out of Virtual Console games in raw format so they are usable elsewhere.

This can be a simple process, but pay attention to the type of game you're extracting. You will need to convert NES games and repair SNES games manually. This is because these types of ROMs are altered when made into VCs, and the alterations must be undone to make them usable in raw format.

Game Boy Advance
Game Boy Advance VC games run natively by leveraging the AGB_FIRM, software built into all models of the Nintendo 3DS that allows for native playback. The AGB_FIRM was only officially used as part of the initial Ambassador Program, but is compatible with all GBA games.

As they run natively, VC injects for these games do not have any extra features such as savestates or fast-forwarding.

As they are ran via native playback, all external programs will not work while playing a GBA VC game. This means remapping buttons, streaming, use of external controllers, etc. are not possible in this mode.

Pressing certain keycombos in these games will create unique effects, as follows:
 * Holding while booting into the game will enable pixel-perfect mode until the next time you launch it.
 * If you press HOME but do not press A, holding and pressing on the D-Pad in this menu will manage the screen's backlight.
 * and increase/decrease brightness, respectively.
 * and disable/enable power-saving mode, respectively.

NES & Famicom Disk System / Game Boy / Game Boy Color
NES/GB/GBC VC games run via emulators that have identical UIs. They all allow the use of a single savestate and the ability to reset the game at any time.

These games are small enough to run at full speed on both old and new models.

Pressing certain keycombos in these games will create unique effects, as follows:
 * NES: While playing, pressing ++ switches between players 1 and 2.
 * GB: While booting in, holding will enable perfect-pixel mode. While playing, pressing ++ switches the background tint between gray and green.
 * GBC: While booting in, holding will enable perfect-pixel mode.

Super NES
SNES VC games use a modified front-end of the NES/GB/GBC emulators.

They allow the use of a single savestate, the ability to reset the game at any time, and the ability to activate or deactivate perfect-pixel mode at any time.

SNES VCs can only be used on New 3DS, as Nintendo's official SNES emulator is heavily unoptimized. If you have an old 3DS, see Snes9x instead.

Game Gear
Game Gear VC injects use a unique front-end that is most like a heavily expanded version of the SNES emulators.

They allow the use of a single savestate, turbo binds, the ability to reset the game at any time, the ability to remap buttons freely, and the ability to alter various graphical settings or the game's overall performance.