Patents Assigned to Racal-Milgo, Inc.
  • Patent number: 4720812
    Abstract: A microprocessor-based system is provided with a non-volatile store (such as a PROM) which stores a bootstrap program, a non-volatile store (such as an EPROM) which stores one or more program overlays, and a programmable volatile store (such as a RAM) which can be written into and read from. When the system is powered up, the microprocessor executes the bootstrap program out of the PROM. The bootstrap program includes instructions which copy the program instructions stored in the EPROM into the RAM. The microprocessor then executes the program instructions out of the RAM. Program instructions may be stored in the EPROM in a plurality of overlays, and individual overlays selected by either the bootstrap program or instructions contained in another overlay may be selectively loaded into the RAM for execution. The EPROM is addressed by a programmable counter which appears to the microprocessor as an input/output device to be written into.
    Type: Grant
    Filed: May 30, 1984
    Date of Patent: January 19, 1988
    Assignee: Racal-Milgo, Inc.
    Inventors: Ming-Luh Kao, Jong-Keung Cheng
  • Patent number: 4541045
    Abstract: A two-bus, two instruction type, pipelined microprocessor having a control means which orders application of instruction and data addresses to a memory and further interleaves instructions and data on a single bus to achieve maximum efficiency in operation.
    Type: Grant
    Filed: September 21, 1981
    Date of Patent: September 10, 1985
    Assignee: Racal-Milgo, Inc.
    Inventor: Philip F. Kromer, III
  • Patent number: 4494232
    Abstract: A statistical multiplexer is disclosed that includes interfaces for asynchronous and synchronous data equipment, and a CPU/control logic. The CPU/control logic cooperates with the interface for the synchronous data equipment for allocating bandwidth to synchronous data equipment when bandwidth is requested and for deallocating bandwidth when bandwidth is no longer required. The allocation and deallocation of bandwidth is controlled by predetermined control frames generated by the CPU/control logic. Such control frames are responded to by the synchronous data equipment interface of the multiplexer originating the control frame and the synchronous data equipment interface of the multiplexer receiving control frames.
    Type: Grant
    Filed: December 4, 1981
    Date of Patent: January 15, 1985
    Assignee: Racal-Milgo, Inc.
    Inventors: William A. Dambrackas, Michael B. Marshall, Larry S. Greenstein, Alex Downie
  • Patent number: 4378535
    Abstract: An automatically adjusted equalizer circuit includes an operational amplifier having a parallel resonant circuit, a voltage controlled resistor, and an amplifier output signal monitoring circuit in a feedback path for the adjustable equalizer. The presence of the parallel resonant circuit in the feedback path causes the amplifier gain to vary with frequency. An input signal to the operational amplifier will be distorted depending upon the particular loss characteristic of a telephone wire to which the input is connected. Automatic adjustment of the voltage controlled resistor, and the presence of the resonant circuit, causes the slope of the gain of the amplifier to inversely compensate for the loss characteristic of the particular line in question. Within the variety of lines, each line will have different loss characteristics as a function of length and gauge of the different telephone lines.
    Type: Grant
    Filed: May 13, 1980
    Date of Patent: March 29, 1983
    Assignee: Racal-Milgo, Inc.
    Inventors: Ran F. Chiu, Yoon B. Park, David E. Nizel
  • Patent number: 4355402
    Abstract: Circuitry for detecting and correcting false equilibrium conditions generated in data modems by sudden changes in gain of an associated transmission system including a false gain detector which detects a low rate of production of symbols of largest magnitude and triggers a final gain circuit which initially jumps the overall system gain and thereafter adaptively adjusts the gain jump to the correct value.
    Type: Grant
    Filed: October 19, 1978
    Date of Patent: October 19, 1982
    Assignee: Racal-Milgo, Inc.
    Inventors: Philip F. Kromer, III, Ran F. Chiu, Ming L. Kao, Henry H. Parrish
  • Patent number: 4351982
    Abstract: A public-key data encryption system employing RSA public-key data encryption including a message encrypter capable of encrypting messages using a non-secret encryption key, a transmitter-receiver coupled to the message encrypter which transmits or receives an encrypted message to or from a remote location, the transmitter-receiver also being coupled to a decrypter capable of decrypting a received encrypted message using a decryption key which is a secret input to the decrypter, and an encryption-decryption key generator, including a microprocessor or other large-scale integrated circuit or circuits formed to generate a sequence of prime numbers beginning with a selected known prime number having a length relatively short with respect to the desired length of the last in the sequence of prime numbers, and which is constructed to form the sequence of prime numbers in the form hP+1 where P is the preceding prime number in the sequence, and to test hP+1 for primality by first determining if hP+1 has a GCD of 1 wi
    Type: Grant
    Filed: December 15, 1980
    Date of Patent: September 28, 1982
    Assignee: Racal-Milgo, Inc.
    Inventors: William J. Miller, Nick G. Trbovich
  • Patent number: 4322576
    Abstract: Communication over data links using binary synchronous protocol that is to be made secure according to the Federal data encryption standard (DES) is enhanced by utilizing an encrypted message format wherein the initialization vector for the DES algorithm is at the trailing end of the message. Additional information or control words may also be strung at the trailing end of the encrypted message format without causing throughput loss while enhancing the security and flexibility of the encrypted message in both point-to-point and multipoint systems.
    Type: Grant
    Filed: December 28, 1979
    Date of Patent: March 30, 1982
    Assignee: Racal-Milgo, Inc.
    Inventor: William J. Miller
  • Patent number: 4270202
    Abstract: Circuitry for automatically and dynamically reconfiguring the channel or port configuration of a modem handling a plurality of ports. A standard signal such as DTR (data terminal ready) is used to provide a code to a master modem indicating the particular port configuration requested by cooperating apparatus. The requested configuration code is continuously compared to a code stored by a shift register controlling the actual modem port configuration. When the requested code changes, an indication of the code change is transmitted to a communicating slave modem and a control signal is sent, after a suitable delay, to the shift register to conform its contents to the newly requested configuration code. During the delay, the slave modem switches to the newly requested configuration. The circuitry follows a defined sequence of configuration switching, dropping channels successively and adding channels by passing through the state where all channels are active.
    Type: Grant
    Filed: February 1, 1979
    Date of Patent: May 26, 1981
    Assignee: Racal-Milgo, Inc.
    Inventors: Edward B. Stuttard, John E. Blackwell, Jessie Chao
  • Patent number: 4263671
    Abstract: A circuit for maintaining proper sampling timing in a data modem wherein main channel equalizer error is correlated with a derivative channel signal to drive a clock correction signal. The derivative channel signal is derived from an equalizer using fewer coefficients than required to derive the main channel equalized signal, and calculation of the equalized derivative and clock correction signal is performed only once every other Baud.
    Type: Grant
    Filed: October 19, 1978
    Date of Patent: April 21, 1981
    Assignee: Racal-Milgo, Inc.
    Inventors: Ran F. Chiu, Henry H. Parrish, Philip F. Kromer, III, Ming L. Kao
  • Patent number: 4213097
    Abstract: An automatic gain control circuit having a coarse analog gain adjustment section producing discrete increments of db gain and a fine digital gain adjustment section. The digital section provides for adjustment of gain through a final increment of db gain to achieve precise gain setting. The output of the digital section is squared and compared to a reference signal to derive an error signal whose value is fed to an apparatus which iteratively determines the precise coarse increment and fine digital settings to achieve the final desired gain setting.
    Type: Grant
    Filed: October 19, 1978
    Date of Patent: July 15, 1980
    Assignee: Racal-Milgo, Inc.
    Inventors: Ran F. Chiu, Philip F. Kromer, III, Ming L. Kao, Henry H. Parrish
  • Patent number: 4193112
    Abstract: A data display communication system wherein data generated locally by a keyboard or generated remotely and communicated by modems is displayed on a display device. Data displayed on the screen can be edited or reformatted prior to storage, print-out, or transmission to a remote location. Data communicated between storage and the central processing unit is handled in blocks that make up one full line of characters on the display device. All edit and format functions are performed on the basis of these blocks of data. Timing for the display device controls the operation of the system. The communication system utilizes a microprocessor operating in conjunction with specific hardware logic to handle display oriented operations.
    Type: Grant
    Filed: January 22, 1976
    Date of Patent: March 11, 1980
    Assignee: Racal-Milgo, Inc.
    Inventors: Judson T. Gilbert, George R. Harrison, Alan R. Holbrook, Michael Levy, John B. Scott, Harris K. Swan