Inspired by a dead (and now lidless) laptop drive that’s on my desk -
What would happen if I messed with the physical orientation of the platters on a hard drive? For this, let’s assume a standard IDE drive, as opposed to SCSI or something ancient like MFM or RLL. And, assume we’re working in a clean room with the correct tools so nothng is damaged.
Rotate one of the platters 180 degrees, or even more radical, flip one upside-down?
My guess with rotating a platter is the drive would just keep going as if nothing happened. Eventually, the data will appear under the head - perhaps just not at the exact instant it was expected.
With the flipped platter, would the drive controller just adapt to finding the sectors under a different head and carry on as usual, or would it go to where it thinks the data should be and mindlessly serve up some other data?
I think it’s most likely you’d end up with a drive that simply didn’t work at all; as well as your actual data, the platters contain the file allocation tables (or equivalent) that your OS needs to locate the files, if that wasn’t bad enough, they also contain servo data that is written at the factory and enables the drive’s electronics to locate the sectors etc in their right places.
I think it most unlikely indeed that you’d end up in a scenario where the system (as a whole) understood what data you were asking for, but gave you something else.
Um, actually, no it doesn’t. Granted, it’s not something I’d think is a good idea. But does the hard drive’s controller have precise enough control over its rotation that screwing around with the platter’s orientation would break the thing? Or does it basically line the head up at the right cylinder (or whatever) and start looking and keep going till it finds the right spot?
There is some formatting done at the factory, once called ‘low level’ formatting, but that term is now a bit confused with other terms. I would assume that would be lost. If you could re-low level format it I’d say it would work.
IMO pretty much what Mangetout said. If you were able to pop off and re-attach a platter (a pretty involved piece of business in itself) the critical servo track info will be completley out of sync. and the drive will likely be confused and give read errors out the wazoo or refuse to read period.
QUOTE: “If you have Windows on your Data machine, You’ll find the OS on the top disc, you’ll recognize it easily, it’s much heavier then the rest of the discs.”
Having dismanltled quite a few HD’s of various pedigree and size to salvage bearings, magnets, and screws I have yet to see any difference in the platters or discs. They all have been identical in size, and thickness. (Never miked any however.)
Well, with bloated software, all things are possible.
I’ve worked as a military computer tech and there was a time I cringed when I saw another tech taking hard drives apart and destroying the platters by bending them with a large screwdriver. At the time, it seemed like a tragic waste of good engineering, but the drives were from older machines, were typically only one gig or less in size, and it was easier to destroy them then format them ten or more times while making sure no classified material was left on them.
Later on, I eneded up doing the same job myself, only I used a drill-press.
Sounds like we need a sacrificial drive and someone with the proper tools to safely get into a drive and get the platters out.
I was able to get the lid off this particular drive without damaging the platters by using small side-cutters to bite into the micro-torx screwheads and loosen them, then use a jeweler’s screwdriver to finish unscrewing, but I’d be hesitant to use such tactics on the actual mechanism.
I’m still not sure rotating a platter would cause much confusion - the track location hasn’t changed - just the timing of when the bits show up is a little different. My understanding of how a drive reads a track is the controller sends the heads to that particular distance from the hub, then the controller starts reading the data off the drive until it finds the desired sector. Considering the platters are spinning at 90-120 revolutions per second (5400 rpm vs 7200 rpm) and there’s a certain inertial lag in moving the heads from point to point, I can’t believe there’s a microsecond or two tolerance for when a sector needs to be passing under the heads.
As for flipping, I just realized that would result in the data and the servo being backwards as the platter spins, so that would be complete data chaos. Guess that would result in a best-case scenario of having a whole bunch of zero-length files as the first byte would be “end of file”
I took a part a 420 gig maxtor in school for the hell of it (got a laugh when my Network Admin teacher approached me and in a serious voice said I might end up damaging the drive…)
I was able to remove cover but the plates were pressed in like a rivet. I couldn’t remove each plate. I also suspect the clearance would change if you flipped a plate over so the head wouldn’t clear (or would be too far).
Err, that should be 420 Meg…not Gig (HAH, I wish).
I didn’t have a chisel and my trusty foot (stomping on the HD trying to break it off) only resulted in a numb leg.
I probably still have the HD. I kept it as art. I’ll see what I can do to it tonight.
I’ve got a number of old, small capacity working hard drives I can try this one, but I suspect we’re going to discover that the spindle has a spline that keys into a notch in the platter, so that it can only be put back on one way.