INT 21 u - Named Pipes - LOCAL DosQNmPHandState
        AX = 5F33h
        BX = handle
Return: CF clear if successful
            AH = pipe mode bit mask (see below)
            AL = maximum number of instances
        CF set on error
            AX = error code
Note:   this function was introduced by LAN Manager but is also supported by
          the Novell DOS Named Pipe Extender, Banyan VINES, OS/2 Virtual DOS
          Machines, and others
SeeAlso: AX=5F32h,AX=5F34h

Bitfields for pipe mode:
 bit 7  set if nonblocking, clear if blocking
 bit 6  set if server end, clear if client end
 bit 2  set if write in message mode, clear if write in byte mode
 bit 0  set if read in message mode, clear if read in byte mode

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