Abstract: A computer-based information exchange system permits customers to request and receive different types of information from various sources. The operation of the system is controlled by an application created using object oriented techniques. These techniques permit simple and straightforward creation and modification of complex automation tasks involving numerous action-object pairs.

Abstract: A computer display system includes a display screen capable of flipping between portrait orientation and landscape orientation and includes a method for repositioning and resizing display windows in response to flipping between such oprientations of the display screen. The windows are moved and resized according to a set of rules to yield displays which take advantage of the new orientation. Where the computer display system includes coordinated, multiple display screens, images controlled for display on fixed-orientation display screens do not change as a result of a flip between orientations of a variable-orientation display screen.

Abstract: A method and system for protecting computer program distribution within a broadcast medium involves encrypting at least a portion of the computer program S.sub.i using an encryption scheme keyed to both an encryption key SK.sub.i and a program identifier i. Each decryption device (PCDD) also has an associated identifier j. Two tables are generated and stored in a memory device: a first table, including correlations between the encryption key SK.sub.i and the program identifier i; and a second table, including correlations between the password key PK.sub.j and the hardware identifier j. A password P.sub.ij is generated based on both the encryption key SK.sub.i and a password key PK.sub.i is retrieved from these tables. The password P.sub.ij is transmitted to the user for subsequent use in decrypting the subject software program contained on the medium.

Abstract: A computer video display acceleration system and method is disclosed for increasing the speed with which modifications can be made to video memory. This system and method uses a video buffer section in system memory with high priority access by a central processing unit which can use the buffer space to make changes rapidly in the stored video information. Once the changes are completed, the data stored in the buffer is written as a block of data to video memory without requiring additional video memory read cycles.

Abstract: A backplane circuit board for connecting network signal lines, bus signal lines, and a number of circuit cards includes a first set of traces from a first network signal connector to connectors for the circuit cards, and a second set of traces from a bus signal connector to the connectors for the circuit cards. The first set of traces and the second set of traces are separated by a uniform distance to provide electrical isolation from one another. The traces are made up of signal-active lines surrounded by signal-neutral lines for further electrical isolation. As one other mechanism for signal isolation, the backplane provides signal-neutral lines on a separate layer from, and in superposition to, the signal-active lines.

Abstract: A chaotic transmitter (100) operates according to preselected chaotic protocols, such as a set of Lorenz equations. Modulation is accomplished by modifying a predetermined parameter of the set of chaotic Lorenz equations with a message signal, thereby producing a spread spectrum chaotic transmitted signal. A corresponding receiver (200) reconstructs a synchronizing drive signal, which is used by a demodulator (412) of the receiver (200) to detect the message signal.

Abstract: A method and apparatus for color screening combines existing halftone pixel matrices into a super cell. Images of different intensities are displayed using such a super cell by selectively illuminating pixels in the super cell in an order that depends both on the illumination order of the original cells and a visitation order for the halftone cells that make up the super cell.

Abstract: Color image information is encoded by grouping together adjacent pixels into blocks, determining which one of several templates each block most closely approximates, and encoding each block in accordance with the rules for a particular template. Data compression without loss of image quality results because the encoding rules for each template ignore irrelevant or duplicative information, thereby saving space for information that is important.

Abstract: The system and method of forming a display from a sequence of blocks of pixel data includes intermediate storage of selected blocks of pixel data in sequence for subsequent selective access in the stored sequence. One or more accesses to a given block of pixel data from intermediate storage provides zoom expansion or compression of displayable images represented by the blocks of pixel data.

Abstract: A bus structure for coupling pixel data to control a raster-type display of objects that are represented by the pixel data in storage operates in real time to assemble pixel data for each pixel-count interval from the pixel data in a plurality of memory segments that are connected in cascade. Priority of displayable overlapping images is restored by comparing priority data stored with associated pixel data to transfer from memory and along the bus structure the pixel data for a pixel-count interval that has the highest associated priority data.

Abstract: Color image information is encoded by grouping together adjacent pixels into blocks, determining which one of several templates each block most closely approximates, and encoding each block in accordance with the rules for a particular template. Data compression without loss of image quality results because the encoding rules for each template ignore irrelevant or duplicative information, thereby saving space for information that is important.

Abstract: A phase-lock circuit for controlling an oscillator includes a sampling gate that operates during a gate interval to pass transitions in a comparison signal derived from the oscillator to produce therefrom an oscillator-controlling error signal that is representative of the phase-error direction and magnitude of the substantially symmetrical relationship between occurrence of transitions in the comparison signal within the interval of the gate pulse.

Abstract: A disposable CO.sub.2 absorber for applications in rebreathing systems uses a flexible bag-like pouch to contain CO.sub.2 absorbent granules. The pouch includes an intake port having a one-way valve at the top of the pouch and an outlet or exhaust port including a perforated cylindrical tube or perforated disk in the bottom of the pouch. Exhaled gas containing CO.sub.2 passes through the one-way valve at the intake port and contacts the absorbent granules where a chemical reaction bonds the CO.sub.2 with the granules. The residual gas, substantially free of CO.sub.2, passes out of the pouch through the exhaust ports for rebreathing by the user. The flexure of the pouch increases the efficiency with which the CO.sub.2 is absorbed.