Patents by Inventor Simon Johnson

Simon Johnson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • EPROM emulator for selectively simulating a variety of different paging EPROMs in a test circuit
    Patent number: 5003507
    Abstract: An EPROM emulator makes use of a simple device with a housing connected to a eprom header which serves to connect the device to a circuit board in conjunction with a microprocessor emulator. Inside the housing are paging and data select circuits and a set of SRAM which are used in place of a traditional EPROM to hold the programming information. To program the device, the EPROM simulator is connected to the circuit board in place of an eprom. A switch on the housing is then turned to place the device in programming mode. The same switch also determines how the device is programmed by accessing the appropriate data lines for the number of pages of EPROM memory which are being emulated. After the switch is properly selected, the emulator is programmed by sending the data through the eprom socket on the circuit board via the microprocessor emulator. After the device is programmed, the switch on the housing is turned to place the device in read-only mode so that it can simulate an EPROM.
    Type: Grant
    Filed: September 6, 1988
    Date of Patent: March 26, 1991
    Inventor: Simon Johnson