Abstract: A hatch cover for deployment over a hatchway formed in a floating roof liquid storage tank permits rapid loading and unloading of inspection or maintenance equipment and minimizes vapor emissions from the tank. The portable hatch cover has two base plates movably connected at a hinge and each defining complementary recesses. A circular flange extends from the bottom surfaces of the base plates to seat the hatch cover in the hatchway. Two door panels are movably connected at hinges to the top surfaces of the base plates. When one or both of the door panels are opened, equipment may be loaded into the tank through the complementary recesses. When closed, the door panels cover the recesses in the base plates. Complementary notches in the door panels provide an opening through which equipment tubing or wiring may extend when the door panels are closed. A collar gasket optionally may be wrapped around the tubing or wiring as a further means to limit vapor emissions from the tank.

Abstract: A helical needle is attached to a surgical probe to aid in the insertion of the probe into a tissue mass. The tip of the helical needle penetrates the tissue mass in advance of the tip of the probe. The probe is rotated to push the helical shaft of the needle into the tissue mass in the direction of rotation. As the helical shaft advances into the tissue mass, the probe advances with it. Rotating the probe in the opposite direction causes the helical needle and probe to withdraw from the tissue mass. Rotation of the probe and needle is more effective in penetrating rubbery and calcified growths than the conventional method of pushing the probe, and it enables the precise placement of the probe. The helical needle also enables insertion of the probe in situations where an inconvenient angle of entry makes it difficult to push the probe along.

Abstract: An integrated circuit including a plurality of connectors for communicating with circuitry within the integrated circuit, a plurality of input/output pads for connecting to external circuitry, a plurality of multiplexors joined to the connectors and the input/output pads, means for providing an external control signal for each multiplexor for joining the plurality of connectors for communicating with circuitry within the integrated circuit to correct input/output pads for connecting to external circuitry for operating the integrated circuit.

Abstract: A method and apparatus for improving bandwidth of sequential access to a display data memory. Display data and tag information related to consecutive data repetitions are stored. No display memory access is needed to output data to the CRT during the time periods when data is being repeated, thus increasing display memory bandwidth. Display data from a location in display memory is stored in a latch, and is output from the latch until the tag information indicates no more data repetitions occur.

Abstract: A hinge includes a first clevis (30), defining a vee-block support (12) and a first limiter surface (44, 46, 48). A cylindrical hinge shaft is supported by the vee-block (12). A second clevis (140) is affixed to the shaft, whereby the second clevis may rotate in response to torques. The second clevis has a limiter surface (148) which coacts with the first limiter to limit rotation of the shaft and second clevis past the deployed state. The second clevis (140) has a cam follower (158) at a predetermined distance from the axis of rotation (2). A cam (100, 104) affixed to the first clevis (30) rotates about a cam axis (3'). The deployed-state engagement between the cam and the follower snugs one end of the shaft into the vee-block, while the rotation limiters snug the other end. A rotational driver (50, 54, 70, 75, 90, 110) urges the cam (100, 104) to rotate in a direction which tends to move the second clevis (140) from the stowed state toward the deployed state.

Abstract: A deployable crossed log-periodic dipole array antenna includes a plurality of bays, each associated with four elongated, flexible antenna elements, each element having an S-shaped cross-section for stiffness. Each bay also includes a spool. The spools have a "squared circle" shape adapted to the natural curvature of the antenna elements. A drum surrounds and is coaxial with all the spools, and the antenna elements extend through apertures in the drum. Rotation of the drum winds and unwinds the flexible antenna elements from their spools simultaneously. When the drum begins to wind for retraction of the elements toward a stowed condition, some bays are arranged so that the elements begin to wind about the spools immediately, whereas other bays are arranged so that the antenna elements rotate about hinges over an angle such as 90.degree. or 180.degree. before beginning to wind onto their spools.

Abstract: A deployable crossed log-periodic dipole array antenna includes a plurality of bays, each associated with four elongated, flexible antenna elements, each element having an S-shaped cross-section for stiffness. Each bay also includes a spool. The spools have a "squared circle" shape adapted to the natural curvature of the antenna elements. A drum surrounds and is coaxial with all the spools, and the antenna elements extend through apertures in the drum. Rotation of the drum winds and unwinds the flexible antenna elements from their spools simultaneously. When the drum begins to wind for retraction of the elements toward a stowed condition, some bays are arranged so that the elements begin to wind about the spools immediately, whereas other bays are arranged so that the antenna elements rotate about hinges over an angle such as 90.degree. or 180.degree. before beginning to wind onto their spools.

Abstract: In a multiunit data processing system, such as a multicontrol unit peripheral data storage system, a least busy one of the units requests work to be done from a busier unit. The busier unit, a work sending unit, supplies work to the work requesting or least busy unit. Work thresholds in the respective units determine when work is to be requested or transferred. In a data storage environment, the transferred work consists of data transfers to be achieved usually asynchronously to connected host activities, such as data transfers between a backing and a front store in a data storage hierarchy.

Abstract: A so-called "roll mode" technique provides block transfer with a disk-type of direct-access data-storage device (DASD). A set of chained commands for accessing record areas enables rapidly accessing a plurality of records within a given DASD cylinder of tracks. The rotational position of the surfaces is checked. The command within the chain, irrespective of its location, having the closest logical rotational proximity to the instant rotational position of the surfaces is selected as the first command in the chain. The chain is executed beginning at the indicated rotational position selected command through the end of the chain and then wrapped to the beginning of the original chain and continuing on until the command immediately preceding the rotational position selected command has been executed.

Abstract: Data is promoted from a backing store (disk storage apparatus termed DASD) to a random access cache in a peripheral data storage system. When a sequential access bit is sent to the storage system, all data specified in a read command is fetched to the cache from DASD. If such prefetched data is replaced from cache and the sequential bit is on, a subsequent host access request for such data causes all related data, up to a predetermined maximum, not yet read to be promoted to cache.

Abstract: A plurality of addressable data storage devices are selectively directly accessed or accessed via a cache memory. Access via the cache memory uses one of a plurality of logical addresses; each of the data storage devices is represented by a plurality of the logical addresses. Each of the data storage devices can be reserved for direct access; such reservation does not apply to device accesses via the cache. Accesses to the devices are queued on a device basis.

Abstract: Data associated with a defective area of a backing store and stored in an alternate area, such as defective and alternate tracks in a direct access storage device, is selectively stored in a high speed buffer front store based upon usage of such data. A first replacement control governs buffer operation for data from good areas of the backing store, and a second independent replacement control governs buffer operation for data from alternate storage areas. Limitations are imposed on the amount of data subject to the second replacement control.

Abstract: Direct access storage devices (DASD) are connected to a host via a cache. Each device can be independently addressed by any one of a plurality of addresses, also termed logical devices and exposures. Since operations between DASD and cache are combined for all of the independent logical devices, resetting operations related to one independent logical device can inadvertently interfere with operations of another independent logical device. To maintain data integrity, a programmed control accommodates logical device independence by using queues and control blocks relating to the DASD and logical devices, respectively.