Abstract: At least one pair of areas on a circuit pack or substrate is allocated for the placement of electromagnetic interference (EMI) absorbing material, e.g., split ferrite cores. All or a portion of the conductor paths for the circuit are routed between pairs of the allocated areas. After the circuit pack is developed and tested, if EMI suppression is required, the EMI-absorbing material extends around the conductors passing between the pairs of allocated areas using holes formed through the allocated pairs of areas. Such holes are formed prior to circuit assembly or, alternatively, are formed only as needed after circuit testing. A clip is used to secure the EMI-absorbing material to the circuit pack. Advantageously, the insertion and securement of the EMI-absorbing material does not require any soldering or special manufacturing tools or fixtures. Accordingly, it can be readily provided in any manufacturing process.

Abstract: At least one pair of areas on a circuit pack or substrate is allocated for the placement of electromagnetic interference (EMI) absorbing material, e.g., split ferrite cores. All or a portion of the conductor paths for the circuit are routed between pairs of the allocated areas. After the circuit pack is developed and tested, if EMI suppression is required, the EMI-absorbing material extends around the conductors passing between the pairs of allocated areas using holes formed through the allocated pairs of areas. Such holes are formed prior to circuit assembly or, alternatively, are formed only as needed after circuit testing. A clip is used to secure the EMI-absorbing material to the circuit pack. Advantageously, the insertion and securement of the EMI-absorbing material does not require any soldering or special manufacturing tools or fixtures. Accordingly, it can be readily provided in any manufacturing process.

Abstract: The disclosed clock adjustment method and apparatus utilizes a periodically transmitted positive or negative predetermined fixed increment clock phase adjustment signal to phase adjust the clocks of the system. The transmitter clock is periodically compared with a common reference clock and a fixed increment clock adjustment signal is transmitted to the receiver which adjusts its clock by applying the fixed increment clock adjustment signal to the common reference clock. The utilization of a predetermined fixed increment clock phase adjustment signal eliminates the need to send the resolution of the clock adjustment and hence reduces the number of data bits required to send clock information over the communication channel.

Abstract: A telautograph system allows a user at one location to write on a special surface, such as a chalkboard, and have the image appear at remote screens. Presently, a user wishing to call attention to an entry already written on the board must make a new line or must circle the item to which the remote viewer's attention is to be drawn. This procedure unduly clutters the image and a system has been devised which provides for a cursor (a graphical hand) to appear on the remote screen when the user touches the input surface at a point. The cursor also appears when the user is writing on the surface so as to call attention to the newly formed images. When pressure on the writing surface is released the cursor remains on the remote screen for a finite period and then automatically disappears, leaving the image unencumbered. When information is being removed from the input surface a graphical eraser appears at the remote screen at the site of the removed information.

Abstract: This disclosure discloses a graphics transmission system using a chalk writing blackboard, a transceiver and a memory. The blackboard is a pressure-sensitive device under control of circuitry in the transceiver producing indicia of the instantaneous position of the chalk on the writing surface. An eraser tray and eraser at its base provide a means to automatically condition the transceiver to interpret a pressure as erase rather than a write command, simply by the absence of the eraser from the tray. Further signal processing yields a more faithful sampling and reproduction of the written signal. A tape recording adjunct is interconnected through a modulation and phase lock loop network that reduces transmission channel and recorder-introduced signal distortion both in the record and the playback modes.