Bitfields for ASPITAPE.SYS current device state:
Bit(s)	Description	)
 0	device currently opened in buffered mode
 1	drive currently opened in nonbuffered mode
 2	rewind drive on last close
 3	drive has been written on
 4	drive has been read from
 5	next read will return 0 bytes
 6	EOM will resemble EOF
 7	drive may be busy rewinding