Linear actuator drives (from ca 1992 onward, 99.99% of all IDE and SCSI drives) park their heads by themselves on power down. They use the motor as generator with the stored rotational energy to move the head well into the parking area. Additional software parking has no effect.
Stepping motor type drives required a large number of stepping pulses, some park in the inside, some on the outside. So, software is required to move the head appropriately before shutdown.
