04/18/2001

Mail. I started plowing through mail last night. I’ve got some good stuff there; time’s just been at a premium due to tax time and trying to put this article to rest. Tonight, I hope…

Fun with hard drives. I was trying to come up with some art to liven up my upcoming Computer Shopper UK article on data recovery. I had a Seagate ST-125 MFM hard drive that I must have picked up on one of my first consulting gigs in the early 1990s. Long ago, I removed the cover of the drive so I could show people what a hard drive looks like inside. So I got the idea to take some pictures of this drive. I had Gatermann come over and bring a Nikon digital camera, and we took some shots of the drive. The dust is visible in some of the early pictures we took–the drive’s just been sitting flat on my desk for as long as I can remember, so it’s no surprise.

From looking at the pictures, it’s clear why you want to handle hard drives with care. The drive’s head hovers literally just above the platter–there’s not enough room for a particle of smoke between them. It doesn’t take much force to make the head smack into the platter, and needless to say, that’s not good for either.

Then I got a crazy idea: power the drive up. I dug out an old IBM PS/1, plugged it in, plugged the drive into an available power outlet, and watched the drive go nuts. When a stepper drive like this one loses track of the head, it smacks the head against the side until it’s sure the head’s at the outside of the disk, then it seeks. (Modern drives aren’t that crude.)

I turned the drive off and watched it park. I had Gatermann take pictures while I played with the power switch. We got some shots of the actuator arm in motion.

The platters on this drive spin at 3600 RPM. Modern drives spin at 5400 rpm, with 7200 rpm becoming mainstream. Top-line high-end drives of today spin as fast as 15,000 rpm. Even though this is a really slow drive, I still didn’t want to touch it while running.

Needless to say, running a hard drive with the cover off isn’t recommended–while most drives aren’t sealed airtight, they heavily filter the little bit of air that comes in. I’ve heard stories of people running drives that have been coverless for years, but that’s just luck of the draw.

I’ve seen some articles on hardware sites lately advocating taking the cover off your drive and replacing it with something transparent so you can watch it run; that’s a great way to void the warranty, and casually opening a hard drive outside a clean room just isn’t a good idea. I wouldn’t do that with any hard drive I intended to trust for more than five minutes. Sure, it’s a cool idea in a way, but very impractical.

As fun as it would be to watch a drive boot with the cover off, I can’t do it with this one. This drive was crashed when I got it, if I remember right, and at any rate, I don’t think I have an MFM controller I could try the drive with anyway. It’s pretty clearly not a healthy drive; it seems like it makes different awful-sounding noises every time you power it up. But what other use is there for a 40-meg MFM hard drive anyway? The drive’s much more useful as a curiosity than for anything else, as long as it doesn’t lose its ability to spin up.

Thanks to Tom Gatermann for taking most of the photos. (I took the first one; you can tell the difference.)

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