INT 2F CU - MS Windows WINOLDAP - SWITCHING ???                                 
	AX = 4602h
Return: ???
Note:	the DOS 5+ kernel intercepts this function and copies the
	  previously-saved MCBsee Memory Control Block from the DOS data segment into the MCBsee Memory Control Block following
	  the caller's PSPsee Program Segment Prefix memory block; in conjunction with AX=4601h, this
	  intercept is used by DOS to avoid corruption of the Windows real-mode
	  heap's end sentinel
SeeAlso: AX=1700h,AX=4601h