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