Abstract: A tension eliminator pillow comprising a block in a generally rectangular configuration having an upper surface, a lower surface, long side walls and short front and rear walls coupled therebetween in a generally rectangular configuration, the side walls, front wall and rear wall being planar in configuration, the lower surface also being planar in configuration; two hemispherically shaped projections symmetrically disposed on opposite sides of a center line midway between the side walls, the walls extending upwardly a distance; the projections being located adjacent to the front wall of the pillow within the lower half of the pillow; and a U-shaped projection symmetrically formed in the central extent of the block, the projection being smoothly curved throughout its extent, the projection having parallel side edges parallel with the side walls, the projection terminating in a curved portion adjacent to the rear wall of the block with the projection initiating adjacent to the hemispherical projections.

Abstract: The embodiment provides selective supervisory disablement of fetch protection for a special storage subarea (such as for the first half of the first 4KB block) while fetch protection is enabled for an area containing the subarea by a single storage protect key. That is, the fetch protect for the subarea (normally provided in the fetch protect for the entire area) by the area's protect key is overriden by the selective subarea disablement control, so that accesses to the subarea are not fetch protected by the storage key. The override protection control is secured by its enablement via a field position in a control register only accessible to supervisory programming. Thus, while fetch protection is set on for a predefined 4KB block, the fetch protect override controls can disable the fetch protection for a portion of the block's real addresses (e.g. addresses 0-2047).

Abstract: Secondary storage subsystems exchange messages and data with host data processing systems and also forward messages between host systems. Host systems thereby communicate with each other in addition to having access to data in subsystem storage. Access to subsystem storage is initiated by a "request" sent from a host to the subsystem. Each request is a message containing an array of one or more commands, each command specifying a transfer of data or a control function to be performed by the subsystem. A subsystem may process more than one request at a time. It also may process the commands in a request in an arbitrary sequence suited to the availability of subsystem resources and data links to host systems. After all commands in a request have been processed the subsystem transmits an associated "completion" message to the host system which originated the request. The completion message indicates the status of completion or abnormal termination of each command in the associated request.