The phrase refers to the act of acquiring a copy of the Pokmon Diamond Version video game, originally released for the Nintendo DS, formatted to be compatible with Game Boy Advance (GBA) emulators through a digital transfer. This typically involves locating and retrieving a ROM file, which is a digital image of the game cartridge, from an online source. For example, an individual might search for instructions on how to play Pokmon Diamond on a GBA emulator using a ROM they obtained.
The perceived importance of obtaining such a file often stems from a desire to experience the game on alternative hardware, bypassing the need for the original Nintendo DS console. Benefits might include portability (playing on a smartphone or other device), the ability to use emulator features such as save states and speed-up, and accessibility for individuals who no longer possess or cannot obtain a Nintendo DS. Historically, the practice of distributing and downloading such files has been prevalent due to the widespread availability of ROMs and emulators across the internet.