Abstract: At least two clusters of CPUs are present in a multiprocessor computer system. Each CPU cluster has a given number of CPUs, each CPU having an associated ID such as an ID number. An additional ID number, not associated with a CPU in the same cluster, is associated with the opposite CPU cluster that appears to the original cluster as a "phantom" processor. A round-robin bus arbitration scheme allows ordered ownership of a common bus within a first cluster until the ID reaches the "phantom" processor, at which time bus ownership passes to a CPU in the second cluster. This arrangement is preferably symmetric, so that when a CPU from the first cluster requests ownership of the bus, it is granted bus ownership by virtue of the first cluster's appearance to the second cluster as a "phantom" CPU.

Abstract: An interface allows a given CPU (Central Processing Unit) to communicate concurrently with a large number of disk drives in a high-performance, low-cost system. Plural seek operations can be performed concurrently, to serve a common processor. Also, heterogeneous physical drives--of any physical or logical configuration (storage capacity, number of heads, and so forth)--can be combined into one or more "logical" drives as seen by a host operating system. An "on-board" embodiment provides an "enhanced" IDE (Integrated Drive Electronics) disk drive that is an extension of the industry-standard IDE drives, allowing an arbitrary number of independently seeking IDE drives on a conventionally single-seeking, two-drive-maximum bus. In a "paddle board" embodiment, low-cost IDE drives of arbitrary physical size, storage capacity and geometry, can be combined simply and inexpensively into a high-performance storage device. For example, a 3.5" 80 MB (megabyte) drive can be transparently combined with a 2.5" 60 MB drive.

Abstract: An interface allows a given CPU (Central Processing Unit) to communicate concurrently with a large number of disk drives in a high-performance, low-cost system. Plural seek operations can be performed concurrently, to serve a common processor. Also, heterogeneous physical drives--of any physical or logical configuration (storage capacity, number of heads, and so forth)--can be combined into one or more "logical" drives as seen by a host operating system. An "on-board" embodiment provides an "enhanced" IDE (Integrated Drive Electronics) disk drive that is an extension of the industry-standard IDE drives, allowing an arbitrary number of independently seeking IDE drives on a conventionally single-seeking, two-drive-maximum bus. In a "paddle board" embodiment, low-cost IDE drives of arbitrary physical size, storage capacity and geometry, can be combined simply and inexpensively into a high-performance storage device. For example, a 3.5" 80 MB (megabyte) drive can be transparently combined with a 2.5" 60 MB drive.

Abstract: An interface allows a given CPU (Central Processing Unit) to communicate concurrently with a large number of disk drives in a high-performance, low-cost system. Plural seek operations can be performed concurrently, to serve a common processor. Also, heterogeneous physical drives--of any physical or logical configuration (storage capacity, number of heads, and so forth)--can be combined into one or more "logical" drives as seen by a host operating system. An "on-board" embodiment provides an "enhanced" IDE (Integrated Drive Electronics) disk drive that is an extension of the industry-standard IDE drives, allowing an arbitrary number of independently seeking IDE drives on a conventionally single-seeking, two-drive-maximum bus. In a "paddle board" embodiment, low-cost IDE drives of arbitrary physical size, storage capacity and geometry, can be combined simply and inexpensively into a high-performance storage device. For example, a 3.5"80 MB (megabyte) drive can be transparently combined with a 2.5" 60 MB drive.