A computer system includes a main body, an integral keyboard formed in the main body, a CPU for executing various types of data processing, a connector through which an external keyboard can be connected to the main body, and a keyboard controller, controlled by the CPU, for receiving key code data supplied...http://www.google.com/patents/US5341316?utm_source=gb-gplus-sharePatent US5341316 - Personal computer system allowing selective use of built-in and external keyboards by means of selector
