Abstract: A computer system which can properly operate even when the power supply is reactivated immediately after its deactivation or when the power supply is deactivated during the execution of a resume process. When after voltage supply to individual components is inhibited by depression of a power supply switch, the power supply switch is depressed again for the voltage supply, a power supply controller determines whether or not a predetermined period of time has elapsed after the voltage supply is inhibited. Upon elapse of the predetermined period of time, the voltage supply to the individual components starts. In the case where a voltage is being supplied to the individual components by depression of the power supply switch, when the power supply switch is depressed again to inhibit the voltage supply, it is determined whether or not a resume process has been completed, or a predetermined period of time has elapsed from the beginning of the voltage supply.

Abstract: A computer comprising a main body, a connector having pins for connecting an external display to the main body, a register for storing data representing a first status or a second status in accordance with the voltage of specified ones of the pins of said connector means, and a display controller for controlling the external display. The computer further comprises a data-reading section for repeatedly reading the data stored in the register and counting the number of times the data representing the first status is read from said register means, and detecting section for determining that the external display is connected to the connector when the number of times the data representing the first status is read from the register reaches a prescribed value.

Abstract: When an AC adapter and a battery are connected to a system, the rapid charge for the battery is started. During the rapid charge, the battery voltage of the battery is detected by a voltage detector. A power supply controller samples the detected battery voltage at predetermined sampling times, thereby to monitor changes in the battery voltage. If the battery voltage rapidly changes at least twice within a predetermined period of time, it is determined that the battery is in a full charge state, and the rapid charge for the battery is stopped.

Abstract: A computer comprising a main body, a connector having pins for connecting an external display to the main body, a register for storing data representing a first status or a second status in accordance with the voltage of specified ones of the pins of said connector means, and a display controller for controlling the external display. The computer further comprises a data-reading section for repeatedly reading the data stored in the register and counting the number of times the data representing the first status is read from said register means, and detecting section for determining that the external display is connected to the connector when the number of times the data representing the first status is read from the register reaches a prescribed value.

Abstract: In a power supply control apparatus capable of connecting an AC adapter, it is determined by a controller whether or not the AC adapter is connected. When a battery is set in the apparatus, it is determined whether the battery is in a low battery state. When the AC adapter is connected and the set battery is in a low battery state, charge operation for the battery is started. During charging, a charged state is monitored on the basis of the current value detected by a current detector and a charge time measured by a timer. When the charge amount exceeds a predetermined amount, or the charge time exceeds a predetermined charge time, the charge operation is completed and the battery is used as a power supply.

Abstract: A CPU in a power source controller generates various error status data, that correspond to various kinds of failure conditions, based on detection signals supplied from a variety of failure detection circuits provided at a power source circuit. The CPU controls an LED in a blinker based on the error status data to light up and extinguish the LED in an orderly fashion which is fixed by the generated data, so that the blinker blinks variously in correspondence with various kinds of power failure conditions. Thus, a various kinds of power failure conditions can be indicated by difference in blinking operation of the blinker.

Abstract: When an AC adapter and a battery are connected to a system, trickle charge is performed with respect to the battery through a trickle charge resistor. During the trickle charging of the battery, the adapter voltage of the AC adapter and the battery voltage of the battery are detected by voltage detectors, respectively. On the basis of a differential voltage representing a difference between the two detected voltages, a power source controller controls the start and stop of the trickle charge at predetermined timings in such a manner that a trickle charge current does not exceed a predetermined value even when the differential voltage increases.

Abstract: There is provided a low-battery detection reference voltage table for memorizing the correspondence between current values and low-battery detection reference voltage values, which is obtained from battery voltage characteristic curves corresponding to different current values. Further, there is provided a low-battery reference voltage correction table for correcting the low-battery detection reference voltage in accordance with a voltage variation. Referring to the low-battery detection reference voltage table on the basis of the value of current output from the battery, the low-battery detection reference voltage corresponding to the current value is obtained. The voltage variation is found from the currently measured battery voltage and the previously measured battery voltage which is memorized. On the basis of the voltage variation, the correction voltage is found with reference to the low-battery reference voltage correction table.

Abstract: In a computer system having an extension slot capable of detachably receiving a display adapter board and display hardware controllers for plasma and CRT displays, respectively, the display hardware controllers are disabled in initialization processing upon power-on. Thereafter, it is checked if a certain type of display adapter board is inserted in the extension slot. When the certain type of display adapter board is not inserted, the display control hardware element for the plasma or CRT display is enabled in accordance with display select data selected in setup processing. When the certain type of display adapter board is inserted, the incorporated display hardware controller interfering with the inserted board is disconnected from the system, and the display adapter board inserted in the extension slot is enabled to have a priority over the incorporated controller.