Page "Motherboard" Paragraph 22

Additionally, nearly all motherboards include logic and connectors to support commonly used input devices, such as PS / 2 connectors for a mouse and keyboard.

Early personal computers such as the Apple II or IBM PC included only this minimal peripheral support on the motherboard.

Occasionally video interface hardware was also integrated into the motherboard ; for example, on the Apple II and rarely on IBM-compatible computers such as the IBM PC Jr. Additional peripherals such as disk controllers and serial ports were provided as expansion cards.