Abstract: A control method and system when a flash memory is used as a semiconductor disk or a main memory in an information processing system. A semiconductor file system comprises a first nonvolatile memory electrically erasable, a second nonvolatile memory not electrically erasable, a volatile memory, a controller which controls the memories, and a control section which controls the controller wherein a physical address corresponding to a logical address specified from an external system is accessed. The first nonvolatile memory stores data for the external system to perform operations, first management information indicating the correspondence between physical addresses at which the data is stored and logical addresses, and second management information indicating a state of the first nonvolatile memory. The second nonvolatile memory previously stores interface information required for inputting and outputting the data from and to the external system and read-only data of the data.

Abstract: A control method and system when a flash memory is used as a semiconductor disk or a main memory in an information processing system. A semiconductor file system comprises a first nonvolatile memory electrically erasable, a second nonvolatile memory not electrically erasable, a volatile memory, a controller which controls the memories, and a control section which controls the controller wherein a physical address corresponding to a logical address specified from an external system is accessed. The first nonvolatile memory stores data for the external system to perform operations, first management information indicating the correspondence between physical addresses at which the data is stored and logical addresses, and second management information indicating a state of the first nonvolatile memory. The second nonvolatile memory previously stores interface information required for inputting and outputting the data from and to the external system and read-only data of the data.

Abstract: In an information processing apparatus including a backboard having a bus for transmitting signals therethrough, at least one module, and a connector to connect the bus to the module, the backboard includes two terminators disposed respectively at both ends of the bus for providing matched termination according to a characteristic impedance of the bus to which the module is connected and a matching resistor disposed between the bus and the module. The matching resistor has a resistance value Rm represented asRm=Z1.multidot.k-Z0/2(0.8<k<1.3)where, Z1 indicates a characteristic impedance of the module, Z0 denotes the characteristic impedance of the bus, and k stands for a coefficient.

Abstract: An information processing system includes a modem communicating with a remote console through a telephone line, an information processing apparatus communicating with the remote console through the modem, a service processor, a power supply continuously supplying power to the modem and the service processor, a power supply supplying power to the information processing apparatus according to commands from the service processor, and a switch connecting the modem to the service processor or the information processing apparatus in accordance with a switching signal from the service processor. The service processor controls the switch to connect the modem to the service processor when the information processing apparatus power supply is in the off state.

Abstract: Bus clock generation circuits divide an output of an oscillation circuit with respect to frequency and output phase state signals. A synchronization circuit judges a setup condition on a second bus on the basis of the phase state signals and, when judging the satisfied setup condition, outputs a shift request signal to a CLK2 generation circuit. This causes the CLK2 generation circuit to change a phase of a clock CLK2 in such a manner that data transmission ends always within one period of the clock CLK2, thus a reducing synchronization overhead.

Abstract: A control method and system when a flash memory is used as a semiconductor disk or a main memory in an information processing system. A semiconductor file system comprises a first nonvolatile memory electrically erasable, a second nonvolatile memory not electrically erasable, a volatile memory, a controller which controls the memories, and a control section which controls the controller wherein a physical address corresponding to a logical address specified from an external system is accessed. The first nonvolatile memory stores data for the external system to perform operations, first management information indicating the correspondence between physical addresses at which the data is stored and logical addresses, and second management information indicating a state of the first nonvolatile memory. The second nonvolatile memory previously stores interface information required for inputting and outputting the data from and to the external system and read-only data of the data.

Abstract: A virtual machine for operating, on a base machine, applications software for a target machine. The virtual machine includes first display control hardware for the base machine, second display control hardware for the target machine, a virtual machine monitor for emulating the operation of the target machine by utilizing the second display control hardware for displaying operation, and a selector for selecting one of the first display control hardware and the second display control hardware depending on whether the virtual machine monitor is operable in a target machine mode or a base machine mode. The OS of the base machine is utilized for the virtual machine without modification.

Abstract: A display system uses a dual-port memory having a random access memory part and a serial access memory part as a frame buffer. Display data is transferred from the random access memory part to the serial access memory part in response to a timing signal of the data transfer. Just prior to the timing signal, an access start disable signal is generated, which has an active period being equal to or longer than an access cycle time of drawing data. When the access start disable signal is active, a draw access from a central processing unit, etc. to the dual port memory becomes disable. Further, address bits for a column of the memory are detected to become all zero and a predetermined value, so that the timing of a real time data transfer and the access start disable signal for the real time data transfer can be generated.