Nintendo game cards are the media format used to distribute video games for the Nintendo DS and Nintendo 3DS systems. The game cards resemble smaller, thinner versions of cartridges for previous portable gaming consoles released by Nintendo, such as the Game Boy or Game Boy Advance. The mask ROM chips are manufactured by Macronix and have an access speed of 150 ns. Cards for the Nintendo DS (NTR-005) currently range from 64 megabits to 4 gigabits (8–512 MB) in size (although the maximum capacity is unknown) The cards usually have a small amount of flash memory or an EEPROM to save user data such as game progress or high scores. However, there are a small number of games that have no save memory such as Electroplankton. The game cards are 35.0 mm × 33.0 mm × 3.8 mm (about half the breadth a