Format of HUNTER 16 control block:
Offset	Size	Description	)
 00h	WORD	left edge X co-ordinate
 02h	BYTE	lower edge Y co-ordinate
 03h	WORD	right edge X co-ordinate
 05h	BYTE	upper edge Y co-ordinate
 06h	BYTE	color (00h white, 01h black, FFh invert)
 07h	BYTE	type (00h line, 01h box)
 08h	BYTE	if non-zero (and type is BOX) fill with color