A computer system provides emulation routines that cause a keyboard or mouse to appear to be present to the system software even when the devices are not physically installed. On system start up, this allows installation of appropriate device drivers by the operating system. If a keyboard or mouse is later installed, the emulation responses are discontinued, and a keyboard and mouse operate normally. When the system is placed in a standby state, the keyboard and mouse connectors are totally powered down. Before this power down, the BIOS routines save the configuration state of the keyboard and mouse as recorded by the emulation routines, which have been tracking commands sent to those devices even when those devices are operating. When power is re-enabled to the keyboard and mouse connectors, the configuration of those devices is restored from that saved configuration data. Further, the system detects whether a keyboard or mouse is installed on a particular connector and appropriately maps the keyboard and auxiliary ports to correspond to that connector.