A method for memory management and block paging in a control program that controls the execution of tasks on behalf of a plurality of system computing entities, which selects, transfers blocks of data, such as pages, between storage and memory to maintain in memory only those blocks of data necessary for current system processing requirements. Pages in memory are first identified as not referenced within a preceding time period, for example, since the last examination by a core table scan mechan...

A graphic display system with the ability to use mulitiple memory buffers to produce images with a wide range of colors through bit plane encoding or to present independent application displays or to combine display images through the use of lateral bit encoding. When operated in the lateral bit encoded state, application programs can be associated with independent memory buffers or an application can use the separate buffers to create a display with animation or apparent movement. Each memory b...

A dual mold choke is provided to reduce both differential and common mode electromagnetic interference. Ferrite cores are placed around DC power bus bars providing an inductor limiting differential mode noise and creating a choke reducing common mode noise. The use of E-cores provides a simplified mechanical assembly while providing high levels of noise reduction. An air gap between the center legs of the cores prevents saturation of the choke.

A shadow generation method and apparatus that employs a depth buffer technique to increase the speed of calculation of visible shadows. The system employs pipelined processors to determine visible objects and shadows generated by those objects for one or more light sources. The technique determines whether a shadow exists at a given pixel by evaluating the parity of the number of intersections between shadow polygons and a line of sight extending from the viewpoint. Pipeline processing is introd...

A dual resistance connector system is provided to allow the replacement of power regulators in a computer system without removing power from the operating voltage bus. The new power regulator can be "hot plugged" into the voltage bus without creating a voltage drop on the bus which could lead to voltage transients and logic errors. The low resistance bus bar is augmented by a retractable high resistance contact. The high resistance contact is configured to make electrical connection with the ope...

A process of efficiently managing working storage that unifies the use of queues of fixed size free storage blocks and a global list of blocks of random size. The process implements continuous garbage collection that continually purges unused storage blocks from the fixed size queues to ensure maximum free storage availability. Data processing system throughput is enhanced by reducing the processor overhead required to allocate and return free storage blocks and by reducing the overhead required...

A system and process for enhancing procedural software using object oriented classes. Implementation classes are constructed that provide a defined object oriented interface to applications and are able to invoke the procedural software using defined procedural application program interfaces (APIs). New function is added to the software by adding classes that interface to the implementation classes or directly to the procedural API. The new function builds upon the procedural software without ac...

An interactive computer system for converting user interface presentations from a first application specified format to a second user specified format. The system accepts application program output designed to be displayed on a target type of computer system terminal and, converts the display to a user specified form prior to display. Through conversion apparatus and process the user may specify a customized format for presentation of the data from the application program to take advantage of th...

An electromagnetic contactor assembly with a sensing circuit for determining contactor state based upon the reluctance of the contactor coil. The coil has an electromagnetic coil and a movable contact separated from the coil by a gap when the coil is not energized. Energizing the coil causes the movable contact to close the gap and contact the coil. The determination of the relationship between the reluctance in the coil when the gap is in an open and closed state allows contactor gap status to ...

A ceramic base component packaging assembly with high thermal transfer rates. The packaging assembly includes a molded plastic cover that receives spring washers, ceramic pads, resistive elements or other electronic components, and a thermally conductive ceramic base. The spring washers press the electronic elements against the ceramic base ensuring good thermal transfer. The ceramic base is an effective thermal conductor and electrical isolator for the device.