ABIOS

   (Advanced BIOS) The IBM XT/286 and PS/2 models with 80286 or
higher processors contain two separate BIOSes. The ABIOS is a
protected-mode BIOS which is used by OS/2.  For machines without an
ABIOS, such as the IBM AT, OS/2 loads the equivalent of the ABIOS from
disk.  see also CBIOS