Maxtor ATLAS 10K III - Manual (Page 222)

SCSI Description
5-158 Maxtor Atlas 10K III
 4'<'41 70+6 %QOOCPF J
The REZERO UNIT command sends the heads to cylinder 0 (Logical Block Address
0). Once the heads are on the track, they are not guaranteed to stay at cylinder 0;
periodic calibrations may send them to a different cylinder. If periodic calibrations
have been disabled by using the MAN bit (byte 3, bit 6) of the Vendor Unique
Function Control Page in the MODE SELECT command (15h), the REZERO
UNIT command will cause the drive to perform the next scheduled calibration. The
data format is shown in Table 5-194.
Table 5-194 REZERO UNIT Command Descriptor Block-Data Format
$KV
$[VG
       
0 Operation Code (01h)
1 - 4 Reserved
5 Control