Abstract: A method and apparatus of making a computer system using the peripheral component interconnect (PCI) bus architecture compatible with an Apple computer system are provided. In a preferred embodiment mechanism is used for dedicating interrupt request lines to each of a plurality of input/output (I/O) devices, a mechanism for providing an interrupt request from one of the plurality of I/O devices to a processor, and a mechanism for disabling an interrupt controller on the motherboard of the system (or onboard interrupt controller) so as to allow an interrupt controller residing on an Apple adapter to control the system. The interrupt controller on the Apple adapter contains an input for each of the various I/O adapters attached to the computer system and also provides a request line to the processor.

Abstract: A CHRP compliant Apple adapter is provided. The adapter comprises an onboard interrupt controller to control a peripheral component interconnect (PCI) based computer system. The adapter also comprises a mechanism for disabling a pre-existing system interrupt controller. The onboard interrupt controller contains an interrupt request input for each of a plurality of I/O devices attached to the computer system and also provides an interrupt request to a processor.

Abstract: A method and apparatus for providing automatic frequency and voltage selection for microprocessors in a computer system. Microprocessor identification (ID) bits are burned into a microprocessor during manufacture to specify the correct bus frequency and core voltage. A clock generator and voltage regulator are provided to receive and interpret the ID bits and provide the correct frequency and voltage.