Abstract: A computer virtual memory system key-lock mechanism providing for a variety of key-lock tests and key changes depending on the type of instruction involved. This key-lock mechanism provides the opportunity for users to share use of programs and data in conjunction with the keys and locks assigned to individual users by the facility manager. The mechanism prevents unauthorized access to data and programs simultaneously present within the computer. The invention is mechanized by use of tables which record the keys and locks associated with each segment of data or code. Hardware tests each data or code segment access for compatibility between the keys and locks and causes the memory reference to be rejected if disagreement exists. The keys and locks are short digit sequences associated with the user and referenced segments.

Abstract: A modified least recently used resolving network provides the capability of ignoring any one or more of the signals indicating use of the device in resolving the least recently used status of the devices.

Abstract: In this apparatus for dynamically translating virtual memory addresses to real memory addresses, a master system page table maintained in a memory associates real memory addresses with their corresponding system virtual memory addresses. This table is organized with each virtual memory address stored in it at an index location which is a smaller value formed as a predetermined function of the virtual memory address value. The translator forms the index from the virtual memory address according to the function, enters the table with it, and extracts the corresponding real memory address. In a preferred embodiment, every process (i.e., job) may reference any address in any segment of a process virtual address space, and a dedicated mechanism converts such a process virtual address reference to a system virtual memory address, which then is converted to the real memory address.

Abstract: A disc memory cartridge double-acting handle design increases, over an earlier design, the amount of material resisting stresses at critical points to increase overall stiffness and strength. The increased stiffness and strength allows plastic to be used as the structural material for the mechanism, rather than the metal of the earlier design. The manipulation required is unchanged from the earlier design.

Abstract: Electronic circuitry for improving the speed and accuracy of shifting the magnetic heads of a disk memory from one to another track cylinder. Head velocity is measured with great accuracy by measuring the servo head transit time between adjacent tracks of the servo disk. A microprocessor controller in conjunction with preferred velocity profile data stored in a read only memory provides a control signal to the linear motor control causing the head arm velocity to follow the preferred velocity profile with excellent precision.

Abstract: An improvement to allow easier detaching of a disk memory module from its magnetic attachment to the spindle of a front loading disk drive. In one such type of drive, manually pulling a door open actuates a track-mounted carrier which lifts the disk module from the spindle, breaking the magnetic attraction between them, and transporting the module to the open door for manual removal. To reduce the force necessary to break the magnetic attraction, this invention employs an actuator fixed to the carrier which engages a crank mechanism when the carrier is being pulled to the opening. The crank mechanism pushes against the underside of the module and assists its breaking loose from the spindle. A spring holds the crank assembly in position to re-engage the actuator when the carrier is in the module-detached position.

Abstract: A head arm to be mounted on the carriage of a disc memory drive has a two-stage lift mechanism. This reduces pitch of the head as it is lifted from and landed on the recording medium, reducing the danger that the head will penetrate the air film bearing and scuff the medium, a potential source of damage to either the head or medium.

Abstract: Apparatus for mounting a thin flexible grinding wheel to allow accurate cutting of kerfs therewith. A method of precision assembly of the apparatus is also disclosed.

Abstract: A magnetic transducing core having a transducing face defined by planes whose surfaces comprise substantially parts of ferrite grains, and a method for producing this core. The method involves proper selection of the grit size and binder of a diamond grinding wheel, machining its sides to precise parallelism with each other, mounting it on a highly accurate air bearing, rotating it at high speed, and feeding a work piece ferrite bar from which the core is cut into the rotating wheel. These techniques prevent axial run-out between the edge of the cutting portion of the wheel and the work piece greater than 2.5 microns. A preferred embodiment includes a high pressure jet of coolant impinging on the wheel just ahead of the cutting interface.

Abstract: A disk memory drive mechanism for accepting a disk memory module from a front-located port and conveying it to a seated position on the spindle, and for detaching it from the spindle and conveying it back to the loading port for removal. The module-conveying mechanism is activated by opening and closing the door for the loading port which seals it from the ambient air.

Abstract: Apparatus for mounting a thin flexible grinding wheel to allow accurate cutting of kerfs therewith. A method of precision assembly of the apparatus is also disclosed.

Abstract: In a disk memory module of the type having a permanent housing enclosing the disk and hub, and an opening at the bottom to allow access to the hub by the spindle of the drive unit on which the module is mounted, an improvement for restricting radial movement of the disk and hub within the housing to prevent damage to the disk caused by contact between it and the housing. An annular projection on the interior top surface of the housing fits inside an annular depression in the top of the hub. Radial movement of the hub causes contact between the projection and the side of the depression before the disk edge strikes the inside edge of the housing.

Abstract: An improved magnetic data transducer having a short gap with improved performance during writing, and substantially unaffected performance during reading. This is accomplished by placing one or more of the turns of the winding in the gap, occupying a fraction of the gap adjacent the transducing face. This simulates increasing gap reluctance during writing, by causing increased flux fringing.

Abstract: An improved means for attaching the detachable type of dust shield to a disc memory assembly.

Abstract: A method for forming a flat, thin polyester film into a curved film using heat, peripheral support for the film, and a single die.

Abstract: A structure for supporting a particular type of plasma display panel. The panel is of the type formed of two flat rectangular plates attached to each other face to face with crossed longitudinal axes, the active panel area comprising the face to face surfaces. Support bars with resilient gaskets interposed between themselves and the two plates provide a shock-resistant mounting. Electronic circuitry can be attached to the support bars to provide a compact package with electronic circuitry adjacent to and substantially coplanar with the panel itself.

Abstract: A location sensitive touch panel for use on a rigid substrate. The substrate carries a first set of conductive strips. A resilient plastic membrane overlaying it carries a second set of conductive strips orthogonal to and spaced from the first set. Finger pressure can cause electrical contact between any one of the first set of strips and any one of the second set of strips. The substrate may be either flat or curved, with the membrane conforming to its contour.

Abstract: Two or more processors share a large main memory in which are stored the programs and data sets on which the processors operate. Each processor operates independently from every other one, and selects its tasks for operation on the basis of information contained in tables which may be updated independently by each processor.

Abstract: A circuit card guide adapted to be fastened in a temporary fashion between permanently attached card guides so as to permit the guiding and retaining of circuit cards having a width substantially less than the spacing between the permanent guides.

Abstract: A location sensitive touch panel for use on a rigid substrate. The substrate carries a first set of conductive strips. A resilient plastic membrane overlaying it carries a second set of conductive strips orthogonal to and spaced from the first set. Finger pressure can cause electrical contact between any one of the first set of strips and any one of the second set of strips. The substrate may be either flat or curved, with the membrane conforming to its contour.