Disk ][ Detail Calibration Guide for First Timer

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Disk ][ Detail Calibration Guide for First Timer

I've never calibrated a drive before, but I need to calibrate my Disk II drive so it will read and write floppy disks. I need a really in depth guide that is easy to understand. I have no 60Hz strobe light for getting the drive speed right. I need a solution to get this drive working that doesn't involve shipping it to someone to do it. The heads are good. I know this drive was fully functional before my Apple II Plus stopped working. Some of the setting got messed up though (3 pots) that and I replaced a few components on the board so the tolerances may of changed from when it was originally set. I do have a working Disk II Interface card running in an Apple IIgs.

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Incandescent light bulb. . .

If you are in the USA, use an ordinary incandescent light bulb. That's how the printed interference pattern on the flyweight of the Disk ][ was designed to work. Though the drive is spinning, in the light of a 60Hz frequency strobe/bulb, the pattern appears stationary, when the drive has been adjusted to the correct speed. The frequency of the AC current here is 60Hz. You probably know all of this and aren't in the USA. (But other people read this board and might like to know the background info of this conversation).

If you aren't in the USA, you could buy a small power inverted meant for the US market, connect it to a 12 volt battery, and plug in a simple light fixture with an incandescent bulb into it, and use that as your strobe source.

Before you do the disk speed calibration, I strongly suggest that, once you've taken the housing off of the disk drive, you clean the interior with compressed air, and follow the standard procedure and clean the magnetic heads.

Mutant_Pie

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Re: Disk ][ Detail Calibration Guide for First Timer

I need a really in depth guide that is easy to understand.

Here's an in-depth guide:
http://home.swbell.net/rubywand/Csa2FDRIVE.html
Can't vouch for easy to understand, though.
Here's another one:
http://site.voila.fr/ressources-dsk/diskII/guided2.pdf

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In Canada it's also 60hz. I

In Canada it's also 60hz. I have to find an incandescent bulb laying around and see if I can see it better. Even if it was 50Hz there is also a 50Hz pattern on it too. The idea of the strobe light is that it flashes at a slower fq so that it freezes time or it may flash at 60Hz and just have a better response; all in all it freezes time so it makes it easier to see where it is in the rotation. Would be nice to have one but another method might be better opinion then buying one (if I'm only going to do this once). I'm sure a light bulb doesn't have a good enough response time for this but I'll give it shot. And for a 12V to 120V invert I'm pretty sure the wave most of them generate isn't the stereotypical 60Hz sine wave that you should be getting in your house [or 50Hz if you live in that area]. I think I read on one of the packaging that's it's some form of square or triangular wave at some fq around 50-60Hz.

The housing is off and I did do a through cleaning job.

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That is an in depth guide but

That is an in depth guide but it confused me in a few places. I'll try reading it over again. I'll check out the second one it may be easier to understand. Thanks.

I'll post again when I've got it to work and/or if I need more advice.

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You can do it!

I've calibrated the speed on many Disk ]['s with just the incandescent light bulb method. Use just one light in an otherwise dim room. I should have mentioned the other major method; a disk speed utility, like the one bundled in Copy ][+ software. Of course, you'll have to load the software using a functional drive, if you choose that method.

Mutant_Pie

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