Abstract: An option attach connector has a first indicator bit combination that alerts the device that a public switched telephone network connection has been made to it. The presence of the first indicator bit combination is a signal to the device that telephone, FAX, and E-MAIL communications applications are to be conducted over a PSTN link. The presence of the first indicator bit combination invokes a stored computer program to provide appropriate connections between the PSTN link and the telephone, FAX, and modem hardware in the device. The connections are made by an audio multiplexer that receives control signals from the system CPU, while executing the stored computer program. The program determines the communications application selected by the user and selectively configures the PSTN link to be connected to the either the ear piece and microphone for voice communications, or to the FAX/modem for FAX communications, or to the modem alone for E-MAIL communications.

Abstract: This invention relates to personal computers, and more particularly to personal computer power supplies for supplying electrical power to electrically operated components which manipulate or store digital data. The power supply has a controllable component for responding to the presence and absence of a low voltage direct current electrical signal by enabling and disabling the supply of electrical power to the data processing and storage components, and a signal generator circuit operatively connected with the controllable component and with an alternating current electrical main supply for controllably deriving from the main supply a low voltage direct current signal for delivery to the controllable component, whereby a user of the microcomputer may control energization of the electrically powered data processing and storage components by controlling the application of the low voltage direct current signal from the signal generator circuit to the controllable component.