PORTIBM PC Portable (uses same BIOS as XT) 040D-040F - EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). - Intel 82357
040D R- chip stepping level
040E RW test register 1
040F RW test register 2