Patents Assigned to DuoCor, Inc.
  • Patent number: 6175904
    Abstract: A method and corresponding apparatus provide a backup drive in a computer system having a CPU, a memory, an operating system executing between the CPU and the memory, and a first and second storage device. In accordance with one aspect of the invention, the method includes the steps of designating the first storage device as a primary drive and designating the second storage device as a backup drive. It further includes the step of making the backup drive appear invisible to the operating system. Preferably, the invention accomplishes this step by writing a specified value to the device identification location (address 01FE and 01FF of the boot sector). Thereafter, the invention writes data from the primary drive to the backup drive on a periodic basis, using direct basic input/output service (BIOS) calls. It will be appreciated that, since the drive is “invisible” to the operating system, that direct BIOS calls are required in order to write data to, or read data from, the backup drive.
    Type: Grant
    Filed: January 21, 2000
    Date of Patent: January 16, 2001
    Assignee: DuoCor, Inc.
    Inventor: Dick Gunderson
  • Patent number: 6073220
    Abstract: A method and corresponding apparatus provide a backup drive in a computer system having a CPU, a memory, an operating system executing between the CPU and the memory, and a first and second storage device. In accordance with one aspect of the invention, the method includes the steps of designating the first storage device as a primary drive and designating the second storage device as a backup drive. It further includes the step of making the backup drive appear invisible to the operating system. Preferably, the invention accomplishes this step by writing a specified value to the device identification location (address 01FE and 01FF of the boot sector). Thereafter, the invention writes data from the primary drive to the backup drive on a periodic basis, using direct basic input/output service (BIOS) calls. It will be appreciated that, since the drive is "invisible" to the operating system, that direct BIOS calls are required in order to write data to, or read data from, the backup drive.
    Type: Grant
    Filed: September 3, 1997
    Date of Patent: June 6, 2000
    Assignee: DuoCor, Inc.
    Inventor: Dick Gunderson