Int 2F Fn 4601  CU - Ms Windows Winoldap - Switching ???                   [D]

   AX = 4601h

Return: ???

Note:  the DOS 5+ kernel intercepts this function and copies the MCB
      following the caller's PSP memory block into the DOS data segment;
      in conjunction with AX=4602h, this intercept is used by DOS to
      avoid corruption of the Windows real-mode heap's end sentinel

See Also: AX=1700h,AX=4602h