Well, that was silly

The energy of motion at red heat becomes high enough to break any magnetic coupling and randomise the orientation of the iron atoms. So when it cools down, you've lost any magnetism that was there but you can re-magnetise it. Whether a drive heated to red heat would still work is another matter.

(I've forgotten the proper terms to use to describe the demagnetisation process, but I imagine you get the drift)

they don't park the heads on the platter.

There is no landing zone, neither a flat zone nor a patterned zone.

Parking heads on platter, stopped at maybe 250MB sized drives or so. Drives larger than that, used a plastic parking ramp. Basically, whatever era where the users stopped using the word "stiction", is when the landing zone and platter-landings stopped.

The heads *must* park on the plastic parking ramp assembly.

On emergency power fail, the motor runs in generator mode as the drive spins down, and thus provides sufficient power to "put toys away". On drives with 512MB cache DRAM, there are a few drives like that, which use Flash memory to record the contents of the DRAM, before power is completely lost.

Drives up to 6TB, are "filled with air" and that includes both oxygen and nitrogen. There is a breather hole marked "do not block this hole". This equalizes pressure between HDA and atmosphere. There is a hepafilter on the drive side of the cover, which filters the air as pressure equalizes.

The new Helium drives, have no oxygen or nitrogen inside. There is no breather hole. The drive is guaranteed to have Helium inside for five years. Apparently, there is a SMART parameter for Helium pressure or the like, so there is some kind of capability to check the internal conditions. Helium drives may be between 6TB and 22TB today. It is more likely to start at 8TB, with the Helium fill.

Helium filled drives use less electricity. This is one of the reasons new drives can have *nine* platters inside, in a drive which is still only 1 inch tall. They had to make the platters thinner to achieve this result (you have been warned :-) ).

"9 platters plus helium fill"

Paul

Shredding of drives in massive industrial shredders is the *mandated* way of dealing with obsolescent computers. Management has no idea what data is on any of them so they are all shredded to comply with third party insurance. This is why the computer refurbishers always equip pre-hated computers with a brand new SSD and and Windows -99 installations. So you can get to hate them all over again from scratch.

Takes more energy. Industrial shredders use less power

Shove em in the microwave.