Abstract: Data is accessed by record identification in a peripheral sub-system having cache and back store to transfer the most recently updated version of one or more records stored in the subsystem where one version of a record may be in a back store and a modified version of the record may be in a cache storage, by a method and apparatus including table lookup means for indicating for each record of each track of each device in said back store whether record data stored in cache is modified with respect to a version of the same record stored in back store; and means responsive to the indicating means for transferring the modified or backing store version of a record in accordance with predetermined criteria.

Abstract: Initialization time of a peripheral storage subsystem is reduced. Each subsystem includes a cache store plus a back store having a plurality of DASD storage devides. Storage locations in the cache store are initially allocated for an index table for other subsystem control structures, track buffers, and a limited number of data storing record slots. Limiting the allocation of record slots reduces initialization time. The number of record slots initially allocated is determined by a maximum allowable system initialization time, a total number of subsystem devices to be initialized and the time required to initialize each record slot.

Abstract: A gray scale filter for image data is described which forces a least significant bit of a current pel equal to a most significant bit of the current pel when the most significant bit of the current pel is equal to the most significant bit of a previous and a next pel on a scan line of an image. The invention is embodied in a logic structure employing exclusive ORs to make comparisons between the previous, next and current pels and logic gates to gate the value of the most significant bit of the most current pel to an output representing a filtered least significant bit of the current pel. It should be noted that the value of the most significant bit of the current pel is not changed since only changes between gray-white and white or gray-black and black are filtered by the present invention.

Abstract: A large-area electroluminescent (EL) faceplate for storage CRT is described. The EL faceplate has a non-planar mesh structure which includes individual current limiting resistance between a power source and an array of small-area active regions for improving the faceplate breakdown characteristics. The mesh, which comprises high conductivity strips and delivers power to the active regions, is substantially reduced in area relative to a simple conventional device, and is disposed on thick dielectric nonactive regions to further reduce the possibility of catastrophic breakdown.