Bitfields for supported keyboard functions:
Bit(s)	Description	)
 7	reserved
 6	INT 16/AH=20h-22h supported (122-key keyboard support)
 5	INT 16/AH=10h-12h supported (enhanced keyboard support)
 4	INT 16/AH=0Ah supported
 3	INT 16/AX=0306h supported
 2	INT 16/AX=0305h supported
 1	INT 16/AX=0304h supported
 0	INT 16/AX=0300h supported
SeeAlso: #00511