Format of SyQuest SCSI structure:
Offset	Size	Description	)
 00h	WORD	opcode (see #00287)
 02h	BYTE	target's SCSI ID
 03h	BYTE	target's logical unit number
 04h	BYTE	data direction (00h no data xfer, 01h data in, FFh data out)
 05h	BYTE	host status
		00h successful
		01h selection time out
		02h data over-run or under-run
 06h	BYTE	target status at command completion
		00h successful
		02h check status
		08h busy
 07h	BYTE	command data block length
 08h	DWORD	request data length
 0Ch	DWORD	result data length (actual length of data transferred)
 10h	DWORD	-> CDB (see #03236,#03237,#03238)
 14h	DWORD	-> data buffer
Note:	The handler does not perform a 'Request Sense' command if there was an
	  error