公开(公告)号：BR9101543A

公开(公告)日：1991-12-10

申请号：BR9101543

申请日：1991-04-17

Applicant: IBM

Inventor： DAYAN RICHARD A ,  LAM SON H ,  ZIMMERMAN JOHN P

IPC: G06F9/06 ,  G06F9/24 ,  G06F9/445 ,  G06F12/06 ,  G06F15/20

Abstract: An apparatus and method for reclaiming a portion of random access memory in a personal computer system. The personal computer system comprises a system processor, a memory controller, a random access main memory, a read only memory, and at least one direct access storage device. The read only memory includes operating system microcode. The memory controller regulates communications between main memory and the system processor. In response to signals from the system processor, the memory controller can either execute the microcode out of the read only memory and recover main memory previously used to store the microcode, or disable read only memory, copy the microcode to main memory and execute the microcode out of main memory.