Abstract: An information processing system includes a processor for processing information; a processor bus, a first expansion bus; a host bridge for coupling the processor bus to the first expansion bus; a second expansion bus; a first bus bridge for coupling the first expansion bus to the second expansion bus; a plurality of input/output (I/O) devices coupled to the second expansion bus; and a first storage device for storing a first set of configuration data for the plurality of I/O devices; a second storage device for storing additional configuration data. The first storage device includes a register for storing a pointer for pointing to addresses in the first storage device for forwarding addresses sent from the processor to the I/O devices.

Abstract: To enable wired-OR signal lines to be connected without interlock in a bus linkage unit for connecting the bus of a computer system with the bus of an expansion device or the bus of another computer system through a signal transfer path in which the signal mode is different from those of the buses. A shadow register 46 that acts on the level of wired-OR signal line 51 of the other bus is provided in each system. The level of wired-OR signal lines in each system is sent to the shadow register of the other system through a communication path. When the shadow register of the system is at a predetermined level, said system will not send the level of said wired-OR signal line to the other system. Interlock is eliminated by avoiding repetition of level transfer echoes between both systems in this way. Both systems are further provided with a shadow-shadow register 47 for forming a mirror image of the shadow register of the other system.

Abstract: A bridge for interfacing buses in a computer system having an industry standard architecture (ISA) bus and a peripheral controller interconnect (PCI) bus is coupled between the ISA and PCI buses. Devices coupled to the buses are either PCI bus-compliant devices or are non-PCI bus-compliant devices. A power management device in the computer system is able to place the computer system into a low power suspend mode, a resume mode and an active mode. The bridge has a multi-tiered arbitration device for arbitrating among the PCI bus-compliant devices and the non-PCI bus-compliant devices for control of the computer system. The arbitration device is responsive to the power management device to controllably suspend arbitration when the power management device indicates that the suspend mode is being entered.

Abstract: A computer system having a plurality of devices which transmit and receive information over a channel is presented. The system includes, in the preferred embodiment, a central arbitration control circuit and a local arbiter associated with each device contending for channel access. Each local arbiter, corresponding to a device which desires channel access, generates a channel request signal to the central control circuit. At the appropriate time when the channel becomes available, the central control circuit generates an arbitrate signal. All local arbiters, then contending for channel access, compare the priority level on the arbitration bus with the priority value of the device it is arbitrating on behalf of, with the winning device gaining access to the channel. Each of the local arbiters contains a programmable circuit which enables the arbiter to operate either utilizing a linear priority arbitration technique or a fairness priority arbitration technique.

Abstract: An operating system definition file (ODF) is provided for each operating system stored in a computer system. Each ODF contains a list of keywords that define the operating environment for the particular operating system. During setup, a set configuration program reads each ODF and produces a master record that specifies an ordering of non-system memory regions across all of the operating systems that coexist in the computer system, allowing non-system memory allocations to be made to regions that meet all operating system needs. A merge matrix is used to merge records from the ODFs into a common array allowing the records to be searched to find optimum non-system memory allocations. A memory address space topology table is also built by the set configuration program for use by the operating system during initialization and during allocation of memory.

Abstract: An information handling network includes a plurality of information processing systems having a pretermit system configuration operating under the control of a corresponding number of operating systems where during a initial microcode load (IML) period prior to loading the operating systems a change in the system configuration is detected based on the predetermined system configuration. Upon detecting the change, a communication adaptor device is activated for communicating certain configuration information over the network before loading the operating system.