 The character graphics were created with a special graphics machine ("Character Generator Computer Aided Design") that generated a collection of all the graphical shapes used in the game. Shapes in the collection were assigned numbers that the game's code uses to access, and are combined to form complete images on the screen in real time. The Super Mario Bros. 3 cartridge uses Nintendo's custom MMC3 (memory management controller) ASIC to enhance the NES capabilities. The MMC3 chip allows for animated tiles, extra RAM for diagonal scrolling, and a scanline timer to split the screen. The game uses these functions to split the game screen into two portions, a playfield on the top and a status bar on the bottom, allowing the top portion to scroll as the character navigates the stage while the bottom portion remains static to display text and other information.
