Patents by Inventor Joseph M. Pettinger

Joseph M. Pettinger 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).

  • External interface control circuitry for microcomputer systems
    Patent number: 4794525
    Abstract: External interface control circuitry is described that couples a microcomputer system (100) to an external device (800). The control circuitry includes a microcomputer (102), a power switch (108) for applying power to the external device (800) in response to a PSC* signal, bus control (104) for gating interface signals from the microcomputer (102) with a PD* signal for application to the external device (800) and a peripheral interface adapter (106) for producing the PC and PD* signals and coupling the PI* and READY*/IRQ* signals to the microcomputer (102). A power-up sequence is executed by the microcomputer (102) in response to grounding the PI* signal when the external device (800) is plugged into the microcomputer system (100). Next, the external device (800) produces a binary zero state of the READY*/IRQ* signal, and in response microcomputer (102) produces a binary one state of the PD* signal and thereafter the PC signal.
    Type: Grant
    Filed: February 4, 1987
    Date of Patent: December 27, 1988
    Assignee: Motorola, Inc.
    Inventors: William F. Pickert, Joseph M. Pettinger, Peter Biancalana