INT 13 - Future Domain SCSI BIOS - GET SCSI CONTROLLER INFORMATION

	AH = 18h
	DL = hard drive ID
Return: CF set on error
	    AH = status code (see #00234 at AH=01h)
	CF clear if successful
	    AX = 4321h (magic number)
	    CX = controller family code (see #00249)
	    ---if family code=0200h
		DH = number of exclusively ROM-controlled SCSI devices
		DL = canonical SCSI device number for specified drive
	    ---if family code <> 0200h
		BH = number of exclusively ROM-controlled SCSI devices
		BL = canonical SCSI device number for specified drive
Notes:	also sets an internal flag (non-resettable) which prevents some
	  controller messages from being displayed, allows writes to
	  removable devices (use caution!), and enables the INT 13 interface
	  for more than one drive (i.e. DL >= 81h) in at least some ROM
	  versions
	the TMC-950 does not support any Future Domain BIOS calls; instead,
	  it provides a full CAM implementation (see INT 4F/AX=8100h)
SeeAlso: AH=05h"SCSI",AX=1700h"SCSI",AH=1Bh"SCSI",INT 4F/AX=8100h