Format of Ontrackr_VxD_Data structure:
Offset	Size	Description	)
 00h	BYTE	INT 13h drive number
 01h	DWORD	Delta skew value
 05h	BYTE	Physical  heads (Word 3 of Identify Data)
 06h	BYTE	Physical sectors per track (Word 6 of Identify Data)
 07h	BYTE	Multiple Block Size (Blocking factor)
 08h	BYTE	Read/Write Multiple disable flags
		00001000b	drive supports r/w multiple
		00000100b	do not use read multiple
		00000010b	do not use write multiple
 09h	WORD	Base port address (1F0/170)
 0Bh	BYTE	Hardware interrupt channel (14/15)
SeeAlso: #00298