Int 13 Fn 1C  - Future Domain Scsi Controller - Get Pointer To Free Contr  [d]

   AH = 1Ch
   DL = hard drive ID (any valid SCSI hard disk)

Return: CF set on error
       AH = status code (see AH=01h)
   CF clear if successful
       ES:BX -> first byte of free RAM on controller

Notes: the Future Domain TMC-870 contains 1024 bytes of RAM at offsets 1800h
     to 1BFFh on-board the controller for storing drive information and
     controller status; ES:BX points to the first byte available for other
     uses
   ES contains the segment at which the controller resides; the
     controller's two memory-mapped I/O ports are at offsets 1C00h, 1E00h

See Also: AH=1Bh"SCSI"