Abstract: A hand-held computer is described, which comprises an application program launcher having a multi-point switch. Using the launcher, a user selects and executes one of several application programs registered in a program selection menu. If a launching signal is generated from the launcher when the hand-held computer is at a low power consumption mode, the hand-held computer wakes up from a sleep mode and its mode is converted into a normal mode. At this time, a program selection menu is displayed on a screen. If an application program is not selected before a predetermined time elapses, the hand-held computer re-enters the low power consumption sleep mode without delay. Thus, it is possible to prevent the hand-held computer from consuming unnecessary power.

Abstract: A portable computer having a touch pad as the pointing device adopts a touch pad input control function in accordance with the principles of the present invention. The portable computer system is provided with an input device interface for receiving pointing data generated in the touch pad and for detecting a quantity of time elapsing between occurrence of the pointing data. When the quantity of time exceeds a preset value, the input device interface disables input of the pointing data from the touch pad. The input operation of the pointing data is resumed when pointing data corresponding to a predetermined pattern is inputted. Preferably, the predetermined pattern corresponds to a closed curve which disregards the area and curvature of the closed curve. According to the principles of the present invention, unnecessary pointing operations which occur during inadvertent touches of the touch pad can be effectively prevented.

Abstract: A computer display switching circuit employed in a computer system having an external display and a notebook computer having an internal display includes an external display sensor for checking the state of the external display connector to sense whether the external display is receiving an image signal, and an image signal output controller for controlling an image signal output according to the state sensed by the external display sensor. Accordingly, power to the external display connected to the notebook computer is turned on or off according to the opening and closing of the cover of the internal display of the notebook computer so as to avoid the need for a conventional keyboard hot key. Also, in the case that only an external display is used, the internal display is powered down. Therefore, unnecessary power consumption by the internal display is prevented.

Abstract: A device for controlling data transmission between a docking station and a portable computer includes signal control circuitry connected to the docking station for selectively enabling and disabling data transmission between the docking station and the portable computer to enable and disable expanded operating functions of the portable computer, respectively. The signal control circuitry enables and disables the data transmission between the docking station and the portable computer in dependence upon a first signal indicating a power supply state of the docking station, a second signal indicating a power supply state of the portable computer, and a third signal indicating a connection state between the docking station and the portable computer.

Abstract: Battery-powered equipment for detecting the type of battery installed therein, includes a plurality of types of batteries which can be installed in the battery-powered equipment. Each of the batteries has a positive power terminal, a negative power terminal, and first to third detection terminals. The battery-powered equipment includes a battery type detector for detecting the type of an installed battery according to terminal voltages on the first to third detection terminals of the installed battery. The equipment further includes a battery charger for controlling the charging and discharging of the installed battery on the basis of the detected battery type.

Abstract: A circuit for enabling replacement of a peripheral device connected to a main system in a computer system includes a selecting section that enables a user to select to replace the peripheral device. The replacement will occur while electrical power is being provided to the main system in a computer system. A display section provides a display indicating whether or not the peripheral device may be disconnected from the main system in a computer system. A sensing control section controls a display state of the display section in response sensing a switched state of the selecting section, and transmits corresponding signals to a central processing unit in response to sensing an operating state of the peripheral device. A transmission section selectively enables and disables transmission of interface signals between the peripheral device and the main system in a computer system in dependence upon a control signal provided from the sensing control section.