Int 2F Fn 4602  CU - Ms Windows Winoldap - Switching ???                   [D]

   AX = 4602h

Return: ???

Note:  the DOS 5+ kernel intercepts this function and copies the
     previously-saved MCB from the DOS data segment into the MCB following
     the caller's PSP 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

See Also: AX=1700h,AX=4601h