Abstract: A digital joystick is interfaced to a video game by utilizing diodes for isolation and providing means for strobing the digital joystick. In this manner, the number of conductors required in the cable coupling the digital joystick to the video game circuitry is significantly reduced. In one embodiment, a matrix-type keyboard is included in the remote control unit without adding a significant number of additional conductors. Furthermore, the multiplexer ordinarily required to couple the conductors from the digital joystick and the matrix keyboard is eliminated by this technique.

Abstract: An improved recording cartridge contains a flexible magnetic recording disc. The lower interior major surface of the cartridge provides a smoothing plane for the flexible magnetic recording disc positioned inside the cartridge to allow the disc to rise slightly above the lower interior major surface on a cushion of air while the disc is in rotation. To enhance the stability of the disc and to make the disc conform more readily to the shape of the magnetic head transducer, the lower interior major surface includes a raised portion thereon. This raised portion gives the disc added rigidity and prevents it from flying away from the head during head penetrations and horizontal movement. The remainder of the smoothing plane surface is relatively flat, thereby permitting a thin cartridge configuration to be used.

Abstract: Disclosed is a non-sequential counter. The non-sequential counter comprises, in a preferred embodiment, six inverters coupled together as a three stage shift counter, the input of which is generated according to a feedback term provided by the outputs of each one of the inverter stages. Counters having more than three stages are also disclosed. The feedback term is provided by disclosed decoder circuitry. The non-sequential counter counts through all possible states; thus, a counter having N stages will count non-sequentially through 2.sup.N possible binary states.

Abstract: A method and system for driving a liquid crystal display (LCD) with adjustable drive voltages to match selected ones of a number of different liquid crystal materials utilize variable duty cycle control. Instead of regulating the battery supply voltage to provide desired driving voltage, the driving voltage is disabled for preselected portions of each cycle thereby controlling the root mean square voltage across the LCD segments during both the display-on and display-off states of each display segment to match the liquid crystal material. Two-, three- and four-way multiplexing or any other level of multiplexing may be used in conjunction with this method and system.

Abstract: A flexible disc is provided for the recording and playback of information on a recording surface thereof. The disc is contained within a cartridge housing which protects the recording surface. At least one opening is provided in the disc which is in permanent engagement with at least one pin member of a drive hub, the drive hub providing rotation to the disc when the drive hub is rotated. The outer perimeter of the opening in the disc is larger than the outer perimeter of the pin member so that the disc is free to move laterally along the pin. At least one surface of the cartridge housing acts as a smoothing plane; rotation of the disc causes the disc to rise above such surface creating an air cushion between the flexible disc and surface, with the disc seeking its own level above the smoothing plane surface.

Abstract: A module containing an integrated circuit is disclosed. The module may be repetitively installed in a receptacle located in some electronic apparatus, such as an electronic calculator or video game, with low risk of damage to the integrated circuit or to the receptacle. The module is essentially "box" shaped and is provided with keys and slots for assuring proper orientation within the receptacle. The integrated circuit device is preferably attached via its leads to a substrate located in a chamber located within the module. Contacts are affixed to the substrate and coupled to the leads. These contacts are accessible from the exterior of the module through at least one aperture provided from the exterior to the chamber.

Abstract: An improved arrangement for providing cathode heating current in a visual display wherein pulses of heating current are sequentially applied at brief intervals, the magnitude of the current and the intervals being coordinated with the cathode thermal inertia so as to maintain cathode temperature within an operative range during the off periods, and wherein potentials for activating the display are applied during such off periods.

Abstract: A Read-Only-Memory (ROM) is addressed with a binary coded decimal (BCD) address in an address register or program counter. The ROM comprises an array of memory cells with associated row and column lines for addressing the array. Row and column decoders responsive to the address in the address register identify a unique row and column line for each BCD address. The row and column decoders comprise a plurality of decoders in cascaded levels. The decorders in any given level decode particular bits of the address in the address register; these decoders decode a one-out-of-a-prime-number, which prime number is a factor of the number of memory locations in the array.

Abstract: Disclosed is a parameter interpolator for a speech synthesis circuit. Using a parameter interpolator permits the data rate to the speech synthesis circuit to be lowered inasmuch as the incoming speech data is used to slowly charge the data previously inputted to the values of the incoming data. The speech synthesis circuit includes an input circuit for receiving the target values of the speech data and a memory for stored interpolated values of the speech data. The interpolator includes a circuit coupled to the input circuit and the memory which calculates the difference between the target values and the stored values. Another circuit is used to add a portion of the difference to the values stored in the memory; the particular portion of the difference is equal to 1/2N where N=0, 1, 2 . . . Further, the interpolator is arranged to inhibit the normal interpolation upon certain conditions, such as changes from voiced speech to unvoiced speech, and visa versa.

Abstract: An electronic phase locked loop circuit including a variable period sawtooth generator. The sawtooth generator receives digital reference clock signals and in response thereto generates sawtooth-shaped signals having the same period as said reference clock signals. A sample and hold circuit samples the sawtooth-shaped signals in response to one logical state of a sampling clock. A voltage controlled oscillator is coupled to the output of the sample and hold circuit and oscillates at a frequency proportional to the magnitude of the held sample. A feedback circuit generates the sampling clock by coupling the output of the voltage controlled oscillator to the sampling input of the sample and hold circuit.

Abstract: A flexible disc is provided for the recording and playback of information on a recording surface thereof. The disc is contained within a cartridge housing which protects the recording surface. At least one opening is provided in the disc which engages with at least one pin member of a drive hub, the drive hub providing rotation to the disc. The outer perimeter of the opening in the disc is larger than the outer perimeter of the pin member so that the disc is free to move laterally along the pin. At least one surface of the cartridge housing acts as a smoothing plane; rotation of the disc causes the disc to rise above such surface creating an air cushion between the disc and surface. An opening is provided in the cartridge housing for receiving a recording and/or playback head; the head is moveable within such opening so that it may be selectively indexed to read and/or write information on a plurality of tracks as the disc rotates within the cartridge.

Abstract: An electronic apparatus having a keyboard and an output device, such as a thermal printer unit. The apparatus, including its printer unit, is burn-in tested by an electronic system built into the apparatus. The system includes a memory, a circuit for storing a preselected or predetermined alphanumeric code in the memory and a circuit for repetitively causing the printer unit to print the contents of the memory. A delay system may be incorporated which causes the apparatus to enter a wait mode between printing operations. The period of time that the system is in the wait mode may be either a fixed duration or of a selected duration. In the embodiment disclosed, the apparatus is an electronic calculator.

Abstract: Disclosed is a memory system for storing digital data; the memory system of the type which may be implemented, for instance, in an electronic microprocessor or calculator system. The memory comprises an array of transistor memory cells arranged in columns and rows. Column conductors are provided for supplying digital information to each column of such cells and row conductors are provided for enabling each row of cells to store digital information being received on the column conductors. A commutator is provided for successively supplying enabling signals to the row conductors and another commutator is provided for successfully connecting the column conductors with an input/output bus in the memory system. The provision of the commutators with the array of memory cells causes the data, when stored as a word of data, to occupy a register arranged in essentially a diagonal pattern through the array.

Abstract: A digital joystick control includes an elongated shaft member having a spherical ball at one end thereof. First and second socket members are coupled to the joystick to provide a swivel joint between the ball and the socket members enabling movement of the shaft about the ball in any direction; movement of the joystick effects corresponding movement of the socket members. Each of the socket members is connected to a plate member which moves therewith. The plate members have a patterned surface presenting conductive and non-conductive regions in opposing relation to wiper arms which engage the patterned surfaces. The patterned surfaces are coded in such a manner that the locations of the conductive and non-conductive regions of the patterned surfaces with respect to the wiper arms are changeable in response to movement of the shaft of the joystick whereby a unique digital-coded positional signal is generated for preselected incremental positions of the shaft.