Abstract: An electronically controlled mechanical keyboard simulator includes a key selector switch and a signal generating circuit for outputting a preliminary symbol selection signal and a final symbol selection signal, and a keyboard interface circuit. The keyboard interface circuit has a row selector and a column selector, and a scanner for scanning the row and column selectors. The row selector has an enable input terminal which receives the preliminary symbol selection signal as an output disabling signal and the final symbol selection signal as an enabling signal for row identification of a selected information key and output of a row identification signal to the column selector. The column selector is operative upon receipt of the row determining signal for selecting an information column identifying output terminal and outputting the selected row information thereon to a microprocessor for data retrieval and communication of the selected information to the user by a display or audio device.

Abstract: A frequency modulated transmitter including a reference frequency source providing a reference frequency to a phase locked loop circuit. The phase locked loop circuit provides a frequency output signal stabilized in accordance with this reference frequency and in accordance with a feedback signal. The phase locked loop circuit further includes a data input circuit that adjusts the output frequency in accordance with input data. Also included is the feedback circuit that provides the feedback signal to the phase locked loop circuit. This feedback circuit is derived from the frequency output signal. A synchronization circuit is connected to the feed back circuit and synchronizes the output of the feedback circuit with the reference frequency signal and the input data.

Abstract: An improved communications device for use by handicapped persons utilizes a list of elements such as the alphabet. The list is sequentially scanned in a forward direction at a speed faster than the response time of the individual. Upon a first operation of a switch, the scan reverses direction and presents the elements at a slower speed. A second switch operation by the user indicates the selection of the desired element. Display and interpretation of the selected element is made in whatever manner desired, and the scanning process is repeated to enable selection of the next element.

Abstract: A network multiple physical layer interface connected to a first communications network physical layer and through a MODEM to a second physical layer wherein the interface includes circuitry for selecting transmission and reception frequency bandwidths for the MODEM and also includes a first transceiver circuit for receiving data from the first physical layer and transmitting this data through the MODEM to the second physical layer and a second transceiver circuit for receiving data from the second physical layer through the MODEM and retransmitting the data on the first physical layer. The interface further includes user selectable modes to enable this interface to provide a communications connection to only the first physical layer or to both physical layers. Still further, the interface includes collision avoidance circuitry to prevent any transmissions onto the network through this interface when information traffic is present on either physical layer.

Abstract: A user operated switch has a support frame mounted to a person's body. A first electrical contact is mounted on and extends from the frame. Contacting structure includes a friction device positioned against a portion of the person's skin and is supported by an electrically conductive support arm. An electrically conducting lever arm has a first end mounted in the friction device in electrical contact with the support arm. A second end of the lever arm is located adjacent the first contact. Skin movement will cause contact between the first contact and the lever arm. The switch may be modified to act as a double throw, single pole switch.