Patents Assigned to BTI Computer Systems
  • Patent number: 4390944
    Abstract: Circuitry for affording access to a common passive bus by a plurality of computer devices connected to the bus. Each of the devices is provided with the circuitry, which operates in three sequential phases: a bus request phase, an address phase and a data transfer phase. Circuitry interconnecting the bus connections for permitting a device to initiate the bus request phase only if all devices superior to it are not in the bus request phase thereby establishing a priority ranking among the devices. The circuitry also includes a call back system wherein if a given device is unready to receive data when addressed by a source device, such device will, when it is ready, call back the source device that was previously and unsuccessfully attempting to transfer data to it.
    Type: Grant
    Filed: May 13, 1980
    Date of Patent: June 28, 1983
    Assignee: BTI Computer Systems
    Inventors: William L. Quackenbush, Stephen C. Porter, William P. Cargile
  • Patent number: 4380029
    Abstract: A sector of data to be recorded on a magnetic medium is formatted by dividing the data sector into a plurality of data segments. Recorded with each segment is a time code which is identical for all segments in a given sector. During recordation of the data and time code for each segment, a cyclic redundancy check (CRC) signal is generated and the CRC signal is recorded after the data and the time code. As data in a segment is recorded, it is also temporarily stored. The temporarily stored data is combined according to a prescribed function with data in the succeeding segment and that function is temporarily stored for combination with the data in the next succeeding segment so that after all segments of data have been recorded there is a function that uniquely represents the data in all data segments. The function is recorded as a check segment. On recovery of the data, an error in any given segment can be detected by employment of the CRC signal associated with the segment containing an error.
    Type: Grant
    Filed: March 13, 1981
    Date of Patent: April 12, 1983
    Assignee: BTI Computer Systems
    Inventor: Elwood J. Bode