Format of TI Professional PC Device Interface Table:
Offset	Size	Description	)
 00h	DWORD	-> entry point for disk routine
 04h	WORD	bytes per sector
 06h	BYTE	sectors per track
 07h	BYTE	number of heads
 08h	BYTE	number of cylinders
 09h	BYTE	retry count
 0Ah	BYTE	precompensation start
SeeAlso: #01264 at INT 1E