IBM 560 - Manual (Page 69)

Information Word
This area identifies the BIOS service level defined
below.
Information Word
Bit : Real/V86 mode interface support
Bit 1 : 16-bit protected mode support
Bit 2 : 32-bit protected mode support
Bit 3-15 : Reserved
Real Mode Entry Point
The entry point is specified in segment, offset format.
Clients using Real/V86 mode can use this area for the
far-call value.
16-bit/32-bit Protected Mode Entry Point
The code base code address specifies the physical
address for this BIOS, and the client must prepare the
selector for this BIOS. The length should be 64KB.
ThinkPad 560/560E SMAPI BIOS A-5