Address space control apparatus for virtual memory systems

摘要

In a disclosed embodiment of the address space control apparatus, each general-purpose register usable as a base register is associated with another general-purpose register in addition to an access register containing a segment table origin. When a general-purpose register is selected as a base register, the contents of its associated general-purpose register are read out and added to the segment table origin from the associated access register to provide an effective segment table origin. In a modification, the access registers are omitted, and the general-purpose register selected as a base register are used to select an entry in a register or register array containing segment table origins in respective entries. In other embodiments disclosed, general-purpose registers are used in different manners to enhance virtual address space control functions.