Abstract: A method, system and computer program product are provided for implementing memory migration of large system memory pages in a computer system. A large page to be migrated from a current location to a target location is converted into a plurality of smaller subpages for a processor or system page table. The migrated page is divided into first, second and third segments, each segment composed of the smaller subpages and each respective segment changes as each individual subpage is migrated. CPU and I/O accesses to respective subpages of the first segment are directed to corresponding subpages of the target page or new page. I/O accesses to respective subpages of the second segment use a dual write mode targeting corresponding subpages of both the current page and the target page. CPU and I/O accesses to the subpages of the third segment access the corresponding subpages of the current page.

Abstract: Processing multicast messages in a data processing system that includes compute nodes, each of which includes a communications controller, the communications controllers operatively coupled for data communications amongst the compute nodes, each compute node in the data processing system executing at least one logical partition, the data processing system including a hypervisor, where multicast messages are processed by receiving, by more than one of the communications controllers, a multicast message; responsive to receipt of the multicast message, signaling, by one of the communications controllers, an interrupt in the hypervisor without signaling an interrupt by any other communications controller; determining, by the hypervisor, that the message received by the interrupt signaling communications controller is a multicast message; and providing, by the hypervisor, the multicast message to at least one logical partition configured to receive multicast messages.

Abstract: Attachment of electronics to optical devices is made by supporting the optical devices on a heat spreader card and the electronics on a separate circuit card. Each card has at least a first major surface, with an optical transducing subassembly mounted perpendicularly from the major surface of the heat spreader card. Electronics, except for transducing elements, are placed on the circuit card. The only direct attachment between the circuit card and the heat spreader card is one or more flexible cables attached to the respective major surfaces. This arrangement mechanically isolates the circuit card from the heat spreader card. The flexible cables include electrical conductors held positionally in a polyimide matrix, which provides for thermal isolation of the heat spreader card and the circuit card.

Abstract: Packaging for an electronics assembly. A base card has a row of elongated slots. A number of individually insertable subassemblies have standoff feet and a pair of offset hooks at their sides. The hooks snap into the slots in such a way that each slot can hold the hooks for four different subassemblies, which are positioned adjacent each other and on both sides of the base card.

Abstract: An electronics system communicates among its subsystems by a free-space optical bus. The bus transmits signals bidirectionally along a single linear axis as polarized beams of light. Each subsystem has a bus interface unit for generating outgoing beams along both axial directions, and for receiving incoming beams from both axial directions. The interface units use laser generators, photodetectors, and amplitude beam splitters.

Abstract: An electronics system communicates among its subsystems by a free-space optical bus. The bus transmits signals bidirectionally along a single linear axis as polarized beams of light. Each subsystem has a bus interface unit for generating outgoing beams along both axial directions, and for receiving incoming beams from both axial directions. The interface units use laser generators, photodetectors, and amplitude beam splitters.

Abstract: An optical fiber link card communication module, and process for fabricating the module, where the module provides a parallel electrical interface to the user, facilitates high speed serial transmission of data over an optical data link, and contains a plurality of converters for performing conversions between both electrical and optical signals. A preferred embodiment of the invention contemplates fabricating the optical communication module on a single multilayer card with all the transmitter electrical components being located on one side of the card, all receiver electrical components being located on the other side of the card, and the transmitter and receiver components being separated by shielding layers in the card. By using two transmitter/receiver pairs (with the transmitters and receivers being located on respective sides of the card) an embodiment of the invention provides for double full duplex communications.

Abstract: An optical fiber link card communication module, and process for fabricating the module, where the module provides a parallel electrical interface to the user, facilitates high speed serial transmission of data over an optical data link, and contains a plurality of converters for performing conversions between both electrical and optical signals. The module further includes edge mounted optical components having leads mounted on the surface of a card (as opposed to standard pin-in-hole type leads) to minimize lead capacitance and inductance from the optical components to the card electronics, on board card control means for the converters and safety shut down means on the same card as the electrical and optical components.

Abstract: An optical communication signal source package and assembly for coupling optical signals to the end of an optical fiber includes first and second semiconductor laser diodes capable of being operated in a redundant fashion for increased reliability or to provide wavelength division multiplexing for increases in bandwidth and information carrying capability. The laser diodes are supported with their mounting flanges in a common plane and are oriented to provide parallel beams of polarized light having perpendicular E-field vectors. A connector carried by the support positions the optical fiber at the target area where an optics system focuses the light beams. An optical coupling device such as a polarizing beam splitter or a holographic beam separator is responsive to the orthogonal light beams to direct both light beams toward the optical fiber with minimum decrease in amplitude. The package includes no moving parts or highly frequency selective components.

Abstract: The invention uses a small sized, low cost, high accuracy, semiconductor laser interferometer to position the transducer in a disc storage system. Light is reflected back over the path to be measured and directly back into the semiconductor laser. This causes the power present in the laser to be varied. Unexpectedly, the output of the photosensor associated with the laser has an asymmetric, sawtooth waveform.

Abstract: An optical serial data bus for connecting logic cards used in a data processing system. The bus uses semiconductor lasers and PIN diodes as transmitters and receivers, transmitting through free space without the use of lenses or other optical elements. Each logic card communicates only with the adjacent cards on either side to minimize the transmission distance.