INT 33 - Mouse Systems MOUSE DRIVER v7.01+ - GET BUTTON ASSIGNMENTS             
	AX = 0073h
	BX = CDEFh
	ES:DX -> 3-byte buffer for button assignments
Return: CX = number of buttons???
	ES:DX buffer filled (default is "LMR")
Note:	also supported by Genius Mouse 9.06
SeeAlso: AX=0067h