Patents Assigned to Quarterdeck Office Systems, Inc.
  • Patent number: 5367658
    Abstract: A method of increasing the amount of directly addressable memory address locations that can be allocated to RAM. An initialization routine is executed to identify ROM's in reserved memory address space that are to be reallocated. Suitable address space in extended memory is located and the ROM's are mapped into extended memory address space. A ROM access interceptor routine is implemented to trap ROM accesses and direct them to the reallocated address space. A ROM access handler routine is implemented to contain the ROM execution and to restore the computer system to a condition where it can continue execution of application or system software after the ROM access is completed. Memory addresses in reserved address space formerly allocated to ROM's can be reallocated to RAM or other memory devices.
    Type: Grant
    Filed: October 7, 1992
    Date of Patent: November 22, 1994
    Assignee: Quarterdeck Office Systems, Inc.
    Inventors: Dan Spear, Larry Mayer
  • Patent number: 5237669
    Abstract: A method of increasing the amount of directly addressable memory address locations that can be allocated to Random Access Memory (RAM). An initialization routine is executed to identify Read Only Memory (ROM's) in reserved memory address space that are to be reallocated. Suitable address space in extended memory is located and the ROM's are mapped into extended memory address space. A ROM access interceptor routine is implemented to trap ROM accesses and direct them to the reallocated address space. A ROM access handler routine is implemented to contain the ROM execution and to restore the computer system to a condition where it can continue execution of application or system software after the ROM access is completed Memory addresses in reserved address space formerly allocated to ROM's can be reallocated to RAM or other memory devices.
    Type: Grant
    Filed: July 15, 1991
    Date of Patent: August 17, 1993
    Assignee: Quarterdeck Office Systems, Inc.
    Inventors: Dan Spear, Larry Mayer