Format of ASPITAPE.SYS mtget parameter block:
Offset	Size	Description	)
 00h	BYTE	ASPI host ID
 01h	BYTE	SCSI target ID
 02h	BYTE	SCSI logical unit number
 03h	BYTE	device parameters
		bit 0: drive must use fixed-block read and write
		bit 7: drive is an ASPI device
 04h	BYTE	current device state (see #01556)
 05h	BYTE	unit number within driver
 06h	WORD	fixed block blocksize
 08h	BYTE	last SCSI status
 09h	BYTE	last SCSI sense key
 0Ah	WORD	last SCSI opcode (packed) (see #01557)
 0Ch	WORD	residual bytes from SCSI opcode