Abstract: Apparatus for generating self-clocking data of a predetermind format simulating control information recorded on a dynamic magnetic medium storage device. The data generator includes means for simulating servo clock signals and encoding means for producing formatted data signals having jitter and phase relationship to the servo signals which are worst-case rather than random. The apparatus is utilized to test data recovery circuits independently of the storage device.

Abstract: In order to achieve the capability to operate a plurality of identical power supplies in parallel, whereby the drawbacks of the conventional master-slave regulator relationship are avoided, the regulator of each power supply is provided with a load current sensor and a secondary differential amplifier circuit responsive to a predetermined load current for controlling the normal reference voltage supplied to the primary, voltage regulating differential amplifier. As a result of the inevitable, within-tolerance differences in the characteristics of two paralleled regulators, one supply will assume constant current operation at the predetermined load current while the other supply will operate at constant voltage and will carry the remainder of the actual load current. As many identical power supplies as necessary for a given application may be operated in parallel, and a single one will automatically operate in the constant voltage mode while the rest operate in the constant current mode.

Abstract: A low-cost electromagnetic interference (EMI) gasket for light-weight equipment enclosures. A pliable strip of electrically conductive material is wrapped spirally about a flexible laminar core structure comprising foam and permanent magnet elements. The gasket is emplaced between two conductive surfaces forming portions of an EMI shield, one of which surfaces is attractive to the magnetic element of the gasket.

Abstract: A method and apparatus is described for generating a data stream incorporating a self-clocking Manchester type code. The data, originally stored in a shift register, is shifted out of the register in bi-level form with a first voltage level representing one binary value and a second voltage level representing a second binary value. The output voltage levels from the shift register are applied simultaneously to two AND gates with an inverter interposed between the shift register and one of the AND gates. Two clock pulse trains are utilized, one having a clock rate twice the clock rate of the other. The clock pulses are respectively applied to the AND gates, the outputs of which are OR'ed and applied to a flip-flop. The output pulses from the OR-gate clocks the flip-flop which toggles to provide a suitably encoded self-clocking data stream at the true and the not true outputs thereof.

Abstract: A method and apparatus is described for receiving a data stream incorporating a self-clocking Manchester code. The data stream is applied to monostable multivibrators which produce pulses at each positive-going and negative-going transition in the voltage level of the data stream. Output pulses from the monostable multivibrators are applied to a third monostable multivibrator which is responsive to only the positive-going pulses applied thereto; the third multivibrator produces an output pulse having a period greater than one-half the bit period, but less than the whole bit period, of the data stream. The positive-going voltage transition of the output of the third multivibrator is used to trigger a clock pulse which is applied to a pair of gates. The gates enable a pair of latches to which the data stream is applied to recover data from the stream and apply the data to a shift register.