Determination of Latest Read-Only Memory on Identical Adapters in IBM Ps/2 Computers
Original Publication Date: 1989-Apr-01
Included in the Prior Art Database: 2005-Jan-27
Disclosed is a method which provides for the automatic determination of the most recent ROM (Read-Only Memory) among ROMs resident on identical adapters installed in an IBM Personal System/2* computer. This method also provides the freeing of ROM space assigned to those ROMs not determined to be the most recent. The IBM Personal System/2 computer features a mechanism by which installed adapters can initialize themselves during computer Power-On Self Test (POST). This mechanism is called ROM Scan. During ROM Scan, computer POST reads data at predetermined address ranges to determine if there is an adapter ROM present and, if so, passes control to that ROM. There are 16 such predetermined address ranges, or ROM "spaces", so there may be multiple adapters, each with its own unique ROM installed in the computer.