Alignment disks, and the creation thereof

--- On Mon, 2/9/09, arcarlini at iee.org <arcarlini at iee.org> wrote: There's not much point in building a device to write alignment disks if all existing disk drives (i.e. what we're going to be aligning) are gone. I've heard this doom and gloom talk about "when all the drives are dead" and "when nothing is left to read $MEDIA" - and while I admit that these things are likely to happen eventually, I also don't believe it's a problem for any of us. Working examples of common microcomputer hardware is everywhere. The trick is to maintain it. I don't see any problem in keeping an Apple IIe in operational condition so that it will still work in the year 2050. And, it's not like this stuff goes away completely. Spring-driven phonographs are still around. Wire recorders are still around. And floppy drives will still be around in 20 years. And yes, media will age - but a lot of it should still be readable, and Athana still makes floppy disks to this day. You can get new media now. I have disks from the 70's that still work fine. But, we're drifting off-topic again. The question is really "Can a hobbyist, with modern technology, build a device to write new alignmnent disks?". I definitely think so. Such a device would definitely be a mix of new and old parts. I mean, why reinvent the disk drive? The basic disk motor, heads, frame, etc. should be fine. The only thing I think that could use an upgrade would be the positioner. Voice coil positioning isn't really what we want here. The only thing we care about is precision, not speed. A stepper would work, just maybe one that's more precise than the one in the drive - or perhaps one that's gear reduced. A leadscrew based drive might be a good candidate, with some kind of precision servo on it. It doesn't matter how fast it is, just as long as it's accurate. Who cares if it takes ten minutes to write an alignment disk? This old equipment can be kept functioning for a very long time - provided that it's maintained. And part of maintaining it is keeping it in good alignment. -Ian