Memory Image Mapping for Personal Computer Systems
Original Publication Date: 1988-May-01
Included in the Prior Art Database: 2005-Feb-15
A technique is described whereby memory image mapping is implemented so as to provide over two megabytes of memory to be resident on a personal computer system's planar circuit board. An address decode read-only (Image Omitted) memory (ROM) is used to generate control signals, so as to remap system address space. Address bits are encoded and decoded through the ROM, thereby providing over two megabytes of memory, resident on the planar board, without violation of the personal computer system's address bus architecture. System address space between 640 KB and 1.0 MB is allocated to system and optional adapter microcode. This requirement necessitates the mapping of the physical memory addresses to another address space, as shown in Fig. 1.