Kabushiki Kaisha Toshiba

Kazunori Yamaki

Shigeru Sekine

Nobutaka Nishigaki

A sound controller has a signal pin for externally outputting the contents of bit 1 of a control register for controlling its operation mode as a power down signal POWERDOWN# for controlling a power supply to analog audio amplifiers. The power down signal POWERDOWN# output from the signal pin is sent to a power supply controller. The power supply controller switches supply/stop of a power supply voltage VCC2 to the analog audio amplifiers in response to the signal POWERDOWN#. With this control, the power down control of the analog audio amplifiers can be realized in accordance with the state of the sound controller.

Power savings for sound system

In a computer system, when an expansion unit is connected to a computer main body by an interface card, power supply control and I/O port selection are performed at the start of the computer system. In the power supply control, when an expansion power supply of the expansion unit is turned on, a first voltage is supplied to a main power supply of the computer main body. When the main power supply is turned on, main voltages are supplied to computer main body elements from the main power supply in response to the main voltage, and a second voltage is supplied to the expansion power supply through the interface. In response to the second voltage, expansion voltages is supplied to expansion unit elements, and an interface voltage is supplied to the interface. After the power supply control is completed, the I/O port selection is performed. The port addresses of the I/O ports in the computer main body are compared with the port addresses of the I/O ports in the expansion unit. If both port addresses coincide with each other, the I/O ports in the computer main body are disabled, and the I/O ports in the expansion unit are enabled.

Computer system for avoiding coincidence of port address on a bus during

A personal computer includes a connector to which first or second extended memory having different memory capacities is connected. The personal computer further includes a chip type register for storing identification information indicating which of the first and second extended memories is connected to the connector, an address range generation circuit for deriving an address range designated by each row address strobe signal based on the identification information, and a circuit for detecting a row address strobe signal which designates an address range to which the value of a memory address for accessing the first or second extended memory belongs, and activating the detected row address strobe signal.

Personal computer for accessing two types of extended memories having

Computer system capable of connecting expansion unit

A computer system is provided which can be initialized in a condition to operate with one of a plurality of types of display controllers and display modes. The computer system includes a built-in display controller, a switch for enabling use of either the built-in display controller or an optional display controller, a random access memory (RAM) for storing setup data of the system, and a basic input/output system program (hereinafter system BIOS) for actuating the computer system in a condition to operate with a display controller to be selected by the user. The built-in display controller includes a read only memory (ROM) in which an identifier information is written. The system BIOS discriminates the type of the display controller which has been selected by the user by detecting whether or not the identifier information can be read. At least one optional display controller can be connected to the computer system.

Growing community of inventors

Tokyo, Japan

Kazunori Yamaki