Attempting to build on their reputation, Neo-Geo branched out into the handheld space in 1998 with the Neo-Geo Pocket, but got off to a rocky start, releasing a black-and-white unit first before correcting things just a year later with the Neo-Geo Pocket Color (or NGPC).
The folks on the NeoGeo forum wasted no time experimenting, and soon found that the handheld's Bios and game ROMs can be successfully swapped for new games or custom loaders.