Abstract: An arbitrary number of member computer stations are inter-connected by a "party" communication network. Each member station is normally in a high impedance Monitor Mode, for monitoring in-coming messages. The incoming messages latch the monitoring stations into a Receive Only Mode for preventing "interrupts" of on-going communications. Each station continuously monitors the input impedance from the network, to determine when the network is available for transmission. Member stations may enter the low impedance Transmit Mode only when the network is available, because all of the other stations are in the Monitor Mode. A high Z from the network indicates to each station that the network is available. A low Z indicates that another station is in the transmit Mode, and is in control of the network. The random entry of two (or more) parties at the same time is resolved by a Pre-Transmission Test Cycle.

Abstract: An array of thermochromic cells is formed along the end portion of a thin, highly conductive blade. Each cell is visually responsive to a critical temperature incrementally different from the critical temperatures of the other cells. The thermochromic array defines a set of temperature ranges, set off by the critical temperatures. The undersurface of the end portion is pressed down into contact with the hot surface of an object of unknown temperature. The contact pressure is established and maintained constant by bending the blade against the surface. The high elastic strength of the blade permits generous bends having high bending moments without creating a permanent set in the blade. Heat from the hot surface flows upward across the contact area and into the interior of the thin blade. The interior increase in temperature uniformly, with minimum pertubation; and the end portion rapidly obtains an equilibrium temperature substantially equal to the temperature of the object surface.

Abstract: An inner and outer cylindrical cathode are concentrically positioned about a vertical center axis. Vertical anode electrodes extend parallel to the center axis and are symmetrically arranged around the inter-cylinder space between the cathodes. The ends of the anode wires are supported by a pair of insulator rings mounted near the top and bottom of the cathode cylinders. A collection voltage applied to each anode wire for establishing an inward radial E field to the inner cathode cylinder and an outward radial E field to the outer cathode cylinder. The anode-cathode assembly is mounted within a housing containing a conversion gas. A radioactive sample is inserted into the inner cathode which functions as a tubular, deep well radiation window between the sample environment and the conversion gas environment.

Abstract: A deacceleration warning system employs relay isolation between a control loop containing a driver controlled switch, and an operating loop for activating the braking lamps. The relay bypasses the brake pedal switch for use during downshift deacceleration for manually flashing the braking lamps. A vacuum controlled mode switch in the control loop holds the system in a disable mode except during downshift deacceleration. The enable mode is temporarily established when the accelerator pedal is lifted by an increase in the manifold vacuum. Electrical, mechanical, and thermal termination transients within the control loop, the relay structure, and operating loop cause electrical, mechanical and thermal lags which prolong the trailing edge of the manual flash beyond the release of the hand operated switch. This post-release illumination assures that the warning flash cycle will have at least a minimum duration independently of the depression period of the switch.

Abstract: The door on an environmental chamber is provided with a single throw, multi-fingered over-center latching mechanism. The latching fingers extend from a common pivoting assembly, and are operated as a unit by a single handle. A hook on the end of each finger engages a post on the chamber housing. As the handle is operated, the over-center action of the pivoting assembly pulls the door towards the housing causing the gasket to seat. The over-center structure biases the latching mechanism in the latched position.

Abstract: Edge data codes forming an image to be displayed are entered into a random access memory map at addresses corresponding to the scanline number and pixel number of the edge in the display of the image. The edge codes may be entered into the memory map in any sequence (i.e. the sequence of availability, the sequence of generation, or the sequence of display). The addresses in the map which do not receive edge codes, are filled with zeros. The edge codes are retrieved form the map in display order to form a pixel data stream which in sequentially decoded by a look-up table and advanced through a pipeline latch for providing color and intensity control voltages to a D/A converter. Clocked pulses through a timing gate advance each new decoded edge code into the latch. The zeros between the edge codes are detected and disable the timing gate during the non-transition period between edge codes.

Abstract: A phase detector generates an error signal by comparing an input data rate F:in with an output clock rate F:out. The error signal is amplified and applied to the base of an emitter follower circuit. Current from a discharging capacitor within a clock ramp generator flows through the emitter follower and the emitter impedance. The ramp current is controlled by the error signal. The ramp rate F:out is determined by the peak to peak ramp voltage and by the rate of discharge of the ramp capacitor. Variations in the error signal due to F:in drift, cause a compensating change in F:out for continuously maintaining sync between F:in and F:out within each passband. Multi-passband capability is provided by a multi-level current generator which also supplies current through the emitter impedance. The ramp current is reduced to a lower level by an amount equal to the current from the multi-level current source due to the emitter follower action.

Abstract: A set of overlay images are established within a stack of memory maps for superpositioning over a host image on a raster display. The overlay images include legends, grids, cursors, graphs, formats, etc. which are primarily empty background with few actual image pixels. Overlay conflict between corresponding image pixels from different images is resolved by priority logic in accordance with the order of the image planes within the stack. The background pixels maintain a video switch in the host mode for continuing the flow of host data. The absence of background pixels in any plane (that is the presence of overlay image pixels in any plane) keys the video switch to the insert mode for substituting the overlay pixels for corresponding pixels of host data. The resulting composite data stream is decoded and presented to a D/A for display on a CRT. One overlay code is dedicated to background pixels in the overlay memory map, for indicating the absence of overlay pixels to control the status of the video switch.

Abstract: The isolation chamber has an aluminum outer housing with heat transfer fins extending therefrom on the outside vertical surfaces, and insulation material mounted along each inside surface thereof forming a thermally insulative shell. Large aluminum studs extend inwardly from the side surfaces of the housing through the insulative shell for supporting a solid state heat pump. Each pump has a set of inwardly directed heat exchange fins. Each stud and associated pump and inwardly directed set of fins forms a heat conductive path between the surrounding ambient air and the interior of the isolation chamber for controlling the heat flow therebetween. The combined configuration of the inner heat exchange fins defines a central cavity which is temperature controlled to within a desired operating temperature range. A card cage containing the electronic devices is installed in the temperature regulated central region.

Abstract: A truncated, open top, pyramid housing is provided containing a downwardly propagating woofer mounted near the base of the pyramid; a forwardly and slightly upwardly propagating tweeter mounted on the front side of the pyramid; and a pair of rearwardly propagating, crossed polarity, mid-range speakers mounted on opposed sides of the pyramid housing. The push-pull propagation between the opposed mid-range speakers, within a single housing, and similar cooperation between stereo loudspeaker pairs, provides a generally phase distortion free, wide dispersion sound circulation. A polarity switch is provided for establishing the desired cross-phase relationship. The nonparallel side configuration of the housing reduces internal resonance by preventing standing wave formation. The open top functions as an unidirectional port which also reduces internal resonance. The upward portion of each sound cycle is guided out of the speaker housing towards the ceiling by the funneling action of the slanted, tapered sides.

Abstract: A RAM device employs an array of dual gated transistor memory cells accessed by row and column decoding. A separate P type memory region is provided under the column gate which acquires holes as a function of the input data during the write cycle, for controlling the flow of an output electron current during the subsequent read cycle. The write holes flow from the substrate into the P memory region to record a "1" when both the row gate and the column gate are at a low positive potential. The write holes become trapped in the P memory region when the low write voltage on the row gate is replaced by a higher storage voltage. During the read cycle both gates are high, and electron current flows from source to drain along a continuous electron conductive path formed under both gates. The high row voltage causes electron conduction at the surface of the P substrate under the row gate by establishing an N type inversion layer.

Abstract: A light source focuses light on a revolving, apertured color disc. The portion of the light passing through the moving colored apertures is refracted by a projection lens into a small beam. The beam passes through the peripheral area of two large convex lenses sequentially positioned in the projection path. The optical properties of the two lenses combine to define distant focal surface. Each of the convex lenses has smooth optical irregularities randomly formed on each surface thereof for generating convolutions in the distant focal surface. The two lenses rotate slowly in opposite directions causing a smooth animation of the convolutions on the focal surface. The lens rotation continuously introduces new combinations of optical irregularities into the projection path each of which establishes unique and slowly changing convolution arrangements on the focal surface. The image is viewed on a reflective surface positioned proximate the distant focal surface.

Abstract: The terrain objects within the data base for an aircraft flight simulation system are formed by polygon faces and include certain objects formed by repetitive patterns of equally spaced identical polygon faces. More specifically, objects such as runway markings, which are a series of elongated narrow rectangles equally spaced along the length of the runway. The image data is arranged in a particular format including instruction words for identifying the type of data in the data words following each instruction word, and for controlling the flow of data through the image processor. The image data formatted and processed includes:Initialization vectors (Vo), defining the position of landmark points (i.e., the first vertex of the initial polygon of each series of faces).Delta data (shape data), defining the position of other points, (i.e., the remaining vertices of each initial face) with respect to the initial point therefor.

Abstract: A flight simulator combines flight data and polygon face terrain data to provide a CRT display at each window of the simulated aircraft. The data base specifies the relative position of each vertex of each polygon face therein. Only those terrain faces currently appearing within the pyramid of vision defined by the pilots eye and the edges of the pilots window need be displayed at any given time. As the orientation of the pyramid of vision changes in response to flight data, the displayed faces are correspondingly displaced, eventually moving out of the pyramid of vision. Faces which are currently not visible (outside the pyramid of vision) are clipped from the data flow. In addition, faces which are only partially outside of pyramid of vision are reconstructed to eliminate the outside portion. Window coordinates are generated defining the distance between each vertex and each of the boundary planes forming the pyramid of vision.

Abstract: The visual system within an aircraft flight simulation system receives flight data and terrain data which is formated into a buffer memory. The image data is forwarded to an image processor which translates the image data into face vertex vectors Vf, defining the position relationship between the vertices of each terrain object and the aircraft. The image processor then rotates, clips, and projects the image data into two-dimensional display vectors (Vd). A display generator receives the Vd faces, and other image data to provide analog inputs to CRT devices which provide the window displays for the simulated aircraft. The video signal to the CRT devices passes through an edge smoothing device which prolongs the rise time (and fall time) of the video data inversely as the slope of the edge being smoothed. An operational amplifier within the edge smoothing device has a plurality of independently selectable feedback capacitors each having a different value.

Abstract: A digital radar landmass simulator system for an aircraft flight simulator including a mapping radar portion using a computer to transfer pertinent blocks of terrain defining parameters stored in a high volume memory to a high speed memory and a processor accessing the high speed memory for collecting those parameters which correspond to each radar sweep line and for developing therefrom a mapping radar display driving signal and a terrain following radar portion having a profile line memory for storing those sweep line parameters which are collected by the mapping radar portion processor and which coincide with the azimuth angle of a simulated terrain following radar antenna, and a pair of processors for developing therefrom both a terrain following radar display driving signal and an autopilot driving climb/dive signal.

Abstract: The CRT visual system within an aircraft flight simulator receives flight data from a flight simulation computer, and polygon face terrain data from a gaming area data base. The vertices of each polygon face are defined by three object position coordinates. A perspective relationship is maintained between the vertices as the observer changes course in the training flight. The position of each face vertex on the CRT display is determined by two display coordinates. A separate miniraster is constructed for each face based on the position of the vertices. The set of spaced scan lines of progressively increasing and decreasing length thus provided systematically fill in the face area outlined by the face vertices. The vertical position of each vertex will normally not coincide exactly with a scan line, but will fall somewhere between two adjacent scan lines. The endpoint of the scan line subsequent to each vertex must be properly proportioned to accurately position the subsequent edge.