INT 16 - K3PLUS v6.00+ (API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running.  Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes. v2.0+) - GET EXTENDED BUFFER STATE
	AX = AF20h
	BX = 4B33h ('K3')
Return: AX = K3 version (same as returned in BX by AX=AF4Dh)
	ES:BX -> extended keyboard buffer start
	ES:DX -> extended keyboard buffer end
	ES:SI -> next keystroke
	ES:DI -> last keystroke in buffer
	CX = number of keystrokes in buffer
Program: K3PLUS is an extended keyboard driver by Matthias Paul and Axel C.
	  Frinke, originally based on the K3 extended German keyboard driver
	  by Martin Gerdes published in c't magazine in 1988
Note:	this function replaces the identical function AH=20h"K3"
SeeAlso: AH=20h"K3",AX=AF25h,AX=AF4Dh,AX=AF50h,INT 2F/AX=ED58h