Int 21 Fn 5F33  u - Named Pipes - Local DOSqnmphandstate                   [N]

   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

See Also: 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