Int 7F Fn 15  - Alloy Ntnx, Mw386 - Get Channel Status                     [N]

   AH = 15h
   CL = 00h
   AL = channel number
   DX:DI -> status structure (see below)

Return: AL = status (00h-03h) (see AH=12h)

See Also: AH=15h/CL=01h

Format of status structure:
Offset Size    Description
 00h   BYTE    channel status
       bit 0: channel open
       bit 1: channel buffer contains received data
       bit 7: channel locked
 01h   BYTE    sender ID