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5.25 FH Floppy Alignment

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    5.25 FH Floppy Alignment

    Is anyone out there able to align 5.25 DS/DD full height floppy drives? I have 2 MPI's I would like to get up and running. Or is there a place I can get a 5.25 alignment disk? Without paying a fortune?
    *FrankG*

    #2
    Not sure what you consider a fortune.

    How about a small fortune?

    http://www.accurite.com/AAD.html

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      #3
      I consider $95.00 to be a fortune! I'm broke!!!
      *FrankG*

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        #4
        Maybe this is something that 'the community' could arrange for a group-buy of or similar?

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          #5
          Would be a nice thing to have that's for sure! Plus I do have a older Heathkit O'scope that can be used to check alignment and such.
          *FrankG*

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            #6
            Forum Member Tezza has some info available on his blog http://www.classic-computers.org.nz/...andon-m100.htm
            There is some interesting alternate alignment methods discussed in the section at the bottom of the first window "Update: 6th November, 2010."

            I have successfully used the alternate method on two Tandon drives (I know yours aren't Tandon),there might be something there you can apply.

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              #7
              It's much more straightforward and easier to use a Digital Alignment Disk (I use AlignIt). I suspect it's possible to turn them out mass-production style using a slightly modified drive. I have the source for Dysan's Digital alignment program if anyone wants to know what's in one of these things.

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                #8
                Originally posted by Chromedome45 View Post
                Is anyone out there able to align 5.25 DS/DD full height floppy drives? I have 2 MPI's I would like to get up and running. Or is there a place I can get a 5.25 alignment disk? Without paying a fortune?
                Are you sure it's an alignment issue? Can you reliably format a diskette, fill it with data and then read it back (all on the same drive) without errors?

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                  #9
                  Originally posted by Chuck(G) View Post
                  It's much more straightforward and easier to use a Digital Alignment Disk (I use AlignIt). I suspect it's possible to turn them out mass-production style using a slightly modified drive. I have the source for Dysan's Digital alignment program if anyone wants to know what's in one of these things.
                  I'm listening!

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                    #10
                    Take a drive and adjust the disk clamping mechanism so the disk is clamped slightly off-center. Now, being careful to position a blank floppy so that the index hole is matched up with a mark on the spindle, write a formatted track. When the disk is read in an un-modified drive, some sectors will be offset one way; others will be offset the other from "true aligned". The number of sectors that can be read on either side of the "true aligned" will reflect the alignment of the drive--ideally, you should be able to read an equal number of offset sectors from the "true aligned" one.

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                      #11
                      MikeS: When I format a disk in Drive 1 it will work fine in that drive. If I try to read that disk in another drive it's no go. So I would really suspect it's out of alignment. Drive 2 will format to track 38 and bomb out. That track gets skipped so I loose some storage space. Might be a very minor issue if one track is off. But I am not an expert.
                      *FrankG*

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                        #12
                        Originally posted by Chromedome45 View Post
                        MikeS: When I format a disk in Drive 1 it will work fine in that drive. If I try to read that disk in another drive it's no go. So I would really suspect it's out of alignment. Drive 2 will format to track 38 and bomb out. That track gets skipped so I loose some storage space. Might be a very minor issue if one track is off. But I am not an expert.
                        Sounds like a problem with drive 2. Have you got any good factory original disks that you can try reading? Not 100% foolproof but it might help track down where the problem lies.

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                          #13
                          To truly align to a universal specification, you have to have a reference diskette that is manufactured exactly to that specification. I've never had such a diskette but you can align one drive to match another one (your Disk 2 to match your Disk 1) without having a special alignment disk and without use of an oscilloscope or any specialist tools.

                          Dave Dunfield's ImageDisk MS-DOS utility (free) includes an alignment test by which you can step to any track and test read/write on the diskette. It is easy to use, with on-screen menus. You only need to connect your drive to a DOS machine and have access to the alignment adjustment screw (sometimes this is a rather finicky cam).

                          If you have an original manufacturer's software distribution diskette of any content intended for your system, this will be an adequate reference for standard alignment and you can also use it to confirm whether Drive 1 is adequately aligned.

                          If you don't have any external reference diskette, just use a diskette that has been formatted and written in Drive 1, and insert it into Drive 2.

                          Select the drive in ImageDisk, and set it up for the correct diskette sector size, skew format etc. If you don't know all the specs, ImageDisk will make it's own guesses and for alignment purposes this is OK even if wrong. It doesn't matter if the data is read in scrambled form, so long as ImageDisk sees a clear data signal.

                          Select Alignment Test, then navigate to track 20 (the middle of the diskette surface.)

                          Adjust the alignment screw till you can see ImageDisk is reading the track, then press the key to have it read all sectors of the track and further adjust if necessary.

                          Navigate in both directions to Track 0 and to track 40 to confirm reading across the whole diskette, making fine adjustments if needed.

                          When satisfied, tighten the adjustment lock slowly, while the alignment test is still running, so you can see that the tightening does not nudge the carriage off alignment. The tolerances are very narrow.

                          That's all. The adjustment mechanism may vary depending on the model of the drives, but the technique is the same.

                          Rick

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