Int 2F Fn F201  - Winx - Return Address Of Server Buffer                   [W]

   AX = F201h

Return: AX = FFFFh if WINX is busy processing a different request
      = 0000h if successful
       BX:CX = address of server buffer

Format of server buffer
Offset Size    Description
 00h   BYTE    command/status
       00h buffer available
       01h buffer contains result
       02h change directory
       03h execute program
       FFh terminate windows portion of WINX
 01h  ? BYTEs  command (03h) or directory (02h)
  or
 01h   DWORD   result (01h)