Abstract: Apparatus and method for a supervisor for data processing system capable of utilizing a plurality of operating systems. The supervisor includes apparatus for identifying a condition in the data processing system requiring a different operating system. A reserved memory area associated with the currently active operating system is then addressed and register contents of a central processing unit are stored in the reserved memory area. The reserved memory of the operating system being activated is addressed and causes the address of the reserved memory of the operating system being activated, the data related to permitting the physical memory associated with the operating system being activated, contents of registers safestored in the reserve-memory and, data establishing the decor of the operating system being activated are entered in the central processing unit. The operating system to be activated is then enabled, and execution of permitted instructions by the second operating system is begun.

Abstract: A cache clearing apparatus for a multiprocessor data processing system having a cache unit and a duplicate directory associated with each processor. The duplicate directory, which reflects the contents of the cache directory within its associated cache unit, and the cache directory are connected through a system controller unit. Commands affecting information segments within the main memory are transferred by the system controller unit to each of the duplicate directories to determine if the information segment affected is stored in the cache memory of its associated cache memory. If the information segment is stored therein the duplicate directory issues a clear command through the system controller to clear the information segment from the associated cache unit.

Abstract: A pneumatic clamp is disclosed for use in thermomagnetic duplication systems. The clamp comprises a nip member having a web-guiding surface with at least one passageway, means for connecting that passageway to a source of pressurized gas, and means for urging the nip member toward a roller whereby the pressurized gas exiting the passageway(s) will (a) cause a web or webs disposed between that surface and a roller to be pressed against the roller, (b) exert a back pressure urging the web-guiding surface away from the roller, and (c) form an air bearing between the nip member and the web or webs.

Abstract: A novel type of splice trimmer is disclosed for use in a tape winding machine of the type designed to (1) splice magnetic tape into a leader tape connected between two hubs, and (2) take up the added tape on one of the two hubs.The present invention comprises a pneumatically-operated cutting mechanism designed to impart a double concave "Gibson Girl" cut to the spliced tape at the splicing junction so as to substantially eliminate any tape overhang created by misalignment of the tape and leader during the splicing phase of the tape winding operation.

Abstract: Film positioning apparatus is provided for supporting and positioning a disk-shaped film unit, having a plurality of images, in several spaced work positions on a photographic printer, including one position where the film unit is supported adjacent the printing gate aperture. When positioned adjacent the printing gate aperture, the supported film unit is rotationally indexed to position selected images in the aperture.

Abstract: An improved storage bin is provided for storing a flexible tape so that it can be moved in and out of the bin at relatively high speeds. Air is injected to establish a vertical pressure gradient to support the tape in the bin, and the bin has a tapered geometrical construction designed so that when an air pressure gradient is provided in the bin, the tape material will form natural folds as it accumulates in the bin.

Abstract: A memory system includes a cache store and a backing store. The cache store provides fast access to blocks of information previously fetched from the backing store in response to commands. The backing store includes error detection and correction apparatus for detecting and correcting errors in the information read from backing store during a backing store cycle of operation. The cache store includes parity generation circuits which generate check bits for the addresses to be written into a directory associated therewith. Additionally, the cache store includes parity check circuits for detecting errors in the addresses and information read from the cache store during a read cycle of operation. The memory system further includes control apparatus for enabling for operation, the backing store and cache store in response to the commands. The control apparatus includes circuits which couples to the parity check circuits.

Abstract: A machine is provided for automatically loading empty cassettes, each containing a leader, with magnetic tape. The machine is similar in principle to the machine disclosed in U.S. Published Patent Application No. B535,448 wherein sequentially each leader is cut into two sections, one section is sliced to the leading end of a supply tape, a selected length of the supply tape is wound onto the cassette, the supply tape is severed, the trailing end of the supply tape is spliced to the other leader section, and the trailing end of the severed length of supply tape and the other leader section are wound onto the cassette. This invention provides novel means for assuring that the leader is cut into two sections of substantially equal length.

Abstract: A machine is provided for automatically loading empty cassettes one at a time with magnetic tape. Each empty cassette contains a leader.