INT 16 - KEYB.COM KEYBOARD CAPABILITIES CHECK (not an actual function!)
	AH = A2h
Return: AH <= 80h if 122-key keyboard functions (AH=20h-22h) supported
Desc:	this function is called by the DOS 3.2 KEYBxx.COM and DOS 5+ KEYB.COM
	  to determine the highest supported keyboard function
Note:	many BIOSes (including at least some versions of Phoenix and AMIAmerican Megatrends, Inc.(American Megatrends, Inc.) A hardware, software and firmware company founded in 1985.) will
	  destroy AH on return from functions higher than AH=12h, returning
	  12h less than was in AH on entry (due to a chain of DEC/JZ
	  instructions)
SeeAlso: AH=05h"PCjr",AH=92h,INT 2F/AX=AD80h