Why Won't an MVS Cartridge Fit in an AES?
The MVS arcade system and the AES home console share one hardware design and execute identical machine code. Owners can even move the ROM chips from one cartridge type to the other and the game still runs, and every game ROM carries the program options for both home and arcade play. The incompatibility lives entirely in the plastic and the pins.
THE LOCK IS PHYSICAL
Different pinout, on purposeThe arcade and home cartridges have a different pinout, and the record states the reason plainly: they were designed that way to prevent arcade operators from buying the cheaper home cartridges and using them in arcades. Home cartridges were the less expensive pressing of the same game, and a shared connector would have let the professional market cannibalize itself with consumer stock. So the split that defines the Neo Geo (one game, two markets) is protected by the one difference between the two products: the shape of the connection. In a few home releases, the arcade version of the game can even be unlocked with a special code, which underlines how complete the sameness underneath really is. The machine pair itself is introduced on the history of the Neo Geo.