Apparatus for locating memory modules having different sizes within a memory space

摘要

The individual RAMs comprising the memory space of a computer may be of various sizes and are automatically located within a memory space during initialization and address enable information is stored in ID-RAMs on each RAM card. Shift registers on the RAM cards are connected in series and an ID bit is serially clocked through the shift registers during initialization. At each clock pulse the contents of the shift registers are written to the ID-RAMs of each RAM card. The presence of an ID bit at a specific memory location in an ID-RAM on a RAM card indicates that card is to be enabled when the memory location address is accessed; the location of the ID bit within the memory location indicates the particular RAM on the RAM card to be accessed. A detector monitors a transfer of the ID bit between adjacent shift registers so that card memory boundaries, and RAM size, may be known.