Using the V64 involved the solution of two problems: how to boot a game and how to save. In order to get around Nintendo's lockout chip, when using the Doctor V64 a game cartridge is plugged into the Nintendo 64 through an adaptor which connects only the lockout chip. The game cart used for operation had to contain the same lockout chip used by the game backup. The second problem concerned saving progress. Most N64 games saved to the cart itself instead of external memory cards. If the player wanted to keep their progress then the cartridge used had to have the same type of non-volatile memory hardware.