Short: Recalibration tool for floppy drives Uploader: thor@math.tu-berlin.de (Thomas Richter) Author: thor@math.tu-berlin.de (Thomas Richter) Type: hard/misc Version: 1.0 Requires: Kickstart 2.04 or better. One working floppy drive. A joystick. Phillips screwdriver set. Nail polish. _______________________________________________________________________________ Introduction: This little tool can be used to re-calibrate floppy drives manually. This does not mean that I recommend doing so. In case you're "mechanically declined", you should leave this to an expert, or should consider buying a new drive. In case the drive is broken, it is broken, and this tool won't help much. De-calibrated drives show the following symptoms: They read disks written by themselves fine, but fail to read other disks reliable, and disks written to by the decalibrated drive do no longer work reliable in other disk drives. In case the drive just doesn't work at all anymore, something more is broken. In either case, you run into the risk of damaging your hardware even more. Note that I cannot give any guarantee whatsoever that this program and the hints given here are correct, free of errors, etc... The entire risk is up to you. If you break your drive or your computer, tough luck! I refuse to take any responsibilities. Please read the licence conditions at the end of this readme. _______________________________________________________________________________ Step 1: Open a shell and unpack the archive. Read the licence at the end of this readme. Read this readme twice BEFORE performing the operation. Make sure that you feel able to perform all steps mentioned in this readme. If you feel unsure about it, leave this to a technician. _______________________________________________________________________________ Step 2: Building a calibration disk. Required: A well working drive as calibration basis. A DD disk. An audio amplifier connected to the Amiga, as for example the amplifier included in the monitor. (-: Insert the disk into the working drive. The BROKEN drive is of no use here. Turn on the audio. NOTE THAT THE FOLLOWING STEPS WILL OVERWRITE THE CONTENTS OF THE DISK. In the following, I assume that the working drive is df1: and the broken drive is df0:. Enter the following command and listen carefully: TrackDiskSync df1: init This will write the calibration pattern to the disk. Different tracks are encoded by beeps of different pitches. The outhermost track, track #0, comes with the highest pitch. After this step, the disk will show up as BAD: on the workbench. This is fine. _______________________________________________________________________________ Step 3: Opening the bad drive. Required: Phillips screwdrivers. Turn off your computer, disconnect it from the power supply. Open its case, and locate the disk drive. Note that you loose any guarantee by opening the computer! It depends on your system how this procedure looks precisely, please consult your hardware manual. Locate the bad drive and unmount it. Write down how the cables are oriented, i.e. which cable plugs in where and which side of the cable is up. WRITE THIS DOWN. Unplug all cables and remove the disk drive from the case. This might sound easier than it is, especially on the A2K. Now open the disk drive. Again, this heavely depends on the model. Some models come with a single screw at the back of the drive and a snap-in mechanism that holds the upper part of the tin case. Again, it's up to you to locate the screws. Take notes and write down the steps required to close the drive again, remember which screw goes where. _______________________________________________________________________________ Step 4: Locating the fine and coarse adjustments. The drive heads should be now easely visible in the middle of the drive. They run typically on one or two rails, driven by a step motor, possibly over a spindle. The motor sits in the rear part of the case. Near this mechanism, you should find a screw that is fixed by a colorful (mostly green or red) varnish. This is the fine adjustment. By moving the heads carefully, you will also see that they interrupt a light-barrier as soon as they reach the outhermost track. This light barrier is typically hold by a similar screw. This is the coarse adjustment. Typically, it is enough to re-calibrate the fine adjustment (unless you have played already with the drive and all screws are loose anyhow...). As above, I cannot give more precise hints as the exact location of fine and coarse adjustment depend on the drive type. _______________________________________________________________________________ Step 5: Loose the fine adjustment screw. Required: Phillips screwdriver. This will require some force since the screw is fixed by the varnish. Force the screwdriver heavely into the screw head, and turn it. The varnish should then break with a snap and the screw should go loose. Try different screw drivers and avoid breaking the head by trying this step too often. This is not for the mechanically declined people. (-: Loose the screw as much as necessary to be able to move the fine adjustment. It is not necessary to remove the screw completely. _______________________________________________________________________________ Step 6: Mounting the drive temporarely. Required: Rubber, card or some other kind of insulator. Now mount the open (!) drive back into the computer. Connect all the cables. Cut the rubber or the card board into pieces and place them under the edges of the drive such that it can rotate freely. Make sure no part of the electronic of the board is short-cut by the metal case of the computer and make sure that you can remove and insert disks surely avoiding this. _______________________________________________________________________________ Step 7: Recalibrating the drive. Required: Joystick, mouse and keyboard. Audio. Calibration disk. THE FOLLOWING REQUIRES OPERATION ON THE COMPUTER WHILE OPEN. THIS MEANS FOR SOME AMIGA MODELS THAT THE POWER SUPPLY WILL REMAIN UNPROTECTED. IN CASE YOU FEEL UNSURE ABOUT THIS, LEAVE THE FOLLOWING STEPS TO AN EXPERT. I REFUSE TO TAKE ANY RESPONSIBILITY FOR WHAT FOLLOWS. Check if all cables are connected properly, drive(s), monitor, audio and that you can reach the fine adjustment (and possibly the coarse adjustment) easely without touching the power supply. Place the joystick such that you can press the fire button of the joystick by the toe or the knee, leaving both hands to work on the disk drive. Connect the power coard to the computer and boot it. Open a shell. Insert the calibration disk into the open drive carefully. The drive should now spin up and the drive head should move to track zero. It will now step several times as the workbench will try to read the calibration disk, which will fail. Enter the following command in the shell: TrackDiskSync df0: read (provided df0: is the bad drive, of course) Wait until the drive spins up, turn on the audio system. You should now either hear a calibration tone, or noise. As soon as you push the joystick button, the drive should step forwards and backwards again. Keep the button pushed, keep care of the tone and rotate the motor or the fine adjustment control forwards and backwards. The tone should now change its pitch, or should even vanish completely, and finally should re-appear at a different pitch. The different pitches indicate the different tracks you place the drive head on. If the drive head sits on top of a track of the disk, you will hear the tone. If it sits between two tracks, you will hear noise. Move the fine adjustment control until you identify the tone of the highest pitch belonging to track zero. Try to remember the pitch of track zero at the time the calibration disk was written. In case coarse adjustment is required, try to find track zero as best as possible by moving the coarse adjustment first. Only an approximate position has to be found. Tighten the coarse adjustment screw first, then continue with the fine adjustment. Move the fine adjustment to the two extreme places where the tone turns into noise, and place it half between these two points, keeping the joystick button pressed from time to time to keep the motor stepping. Tighten the screw and make sure that the tone stays clear from noise such that the head remains comfortably within the track data. You abort the calibration procedure by pressing the left mouse button. The calibration disk will still show up as BAD: on the workbench. This is fine. _______________________________________________________________________________ Step 8: Checking the drive. Required: Calibration disk. Remove the calibration disk from the open drive. Insert it into the good drive, reformat it and write some data onto the disk. Remove the disk and check whether the re-calibrated drive reads this data fine. Write some additional files on the disk using the bad drive. Remove the disk and check whether the good drive can read the data fine. If everything works to perfection, go to step 9. Otherwise, write the calibration pattern back to the disk, using the good drive as described in step 2. Make sure that the drive head of the broken drive can move freely. The rails might be blocked by dust. Clean the drive, but avoid touching the drive heads. In some cases, one drop of oil onto the rails may help to allow the heads to move freely. DO NOT oil the heads directly. _______________________________________________________________________________ Step 9: Fixing the screws. Required: Nail polish. Use one drop of nail polish on the fine (and possibly coarse) adjustment screw to fix the screw such that it cannot loose itself under operation. Wait until the polish is dry. _______________________________________________________________________________ Step 10: Mounting the drive, and putting things back together. Required: Phillips screw driver set. Turn off the computer. Remove the power coard and all other cables. Unplug the now re-calibrated drive and put it back toghether. Mount the drive back into your computer, and close the computer case again. Now boot the computer and check whether the drive works again by trying to copy some files from and onto disks inserted in the drive. Congratulations! _______________________________________________________________________________ The THOR-Software Licence (v2, 24th June 1998) This License applies to the computer program and documentation known as "TrackDiskSync" and "TrackDiskSync.Intructions". The "Program", below, refers to this program including the mentioned intructions. The "Archive" refers to the package of distribution, as prepared by the author of the Program, Thomas Richter. Each licensee is addressed as "you". The Program and the data in the archive are freely distributable under the restrictions stated below, but are also Copyright (c) Thomas Richter. Distribution of the Program, the Archive and the data in the Archive by a commercial organization without written permission from the author to any third party is prohibited if any payment is made in connection with such distribution, whether directly (as in payment for a copy of the Program) or indirectly (as in payment for some service related to the Program, or payment for some product or service that includes a copy of the Program "without charge"; these are only examples, and not an exhaustive enumeration of prohibited activities). However, the following methods of distribution involving payment shall not in and of themselves be a violation of this restriction: (i) Posting the Program on a public access information storage and retrieval service for which a fee is received for retrieving information (such as an on-line service), provided that the fee is not content-dependent (i.e., the fee would be the same for retrieving the same volume of information consisting of random data). (ii) Distributing the Program on a CD-ROM, provided that a) the Archive is reproduced entirely and verbatim on such CD-ROM, including especially this licence agreement; b) the CD-ROM is made available to the public for a nominal fee only, c) a copy of the CD is made available to the author for free except for shipment costs, and d) provided further that all information on such CD-ROM is redistributable for non-commercial purposes without charge. Redistribution of a modified version of the Archive, the Program or the contents of the Archive is prohibited in any way, by any organization, regardless whether commercial or non-commercial. Everything must be kept together, in original and unmodified form. Limitations. THE PROGRAM AND THE INSTRUCTIONS ARE PROVIDED TO YOU "AS IS", WITHOUT WARRANTY. THERE IS NO WARRANTY FOR THE PROGRAM AND THE INSTRUCTIONS, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM AND THE INSTRUCTIONS IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE OR SHOULD YOU DAMAGE YOUR EQUIPMENT OR SHOULD YOU GET INJURED BY FOLLOWING THE INSTRUCTIONS, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, TREATMENT OR CORRECTION. IF YOU DO NOT ACCEPT THIS LICENCE, YOU MUST DELETE THE PROGRAM, THE ARCHIVE AND ALL DATA OF THIS ARCHIVE FROM YOUR STORAGE SYSTEM. YOU ACCEPT THIS LICENCE BY USING OR REDISTRIBUTING THE PROGRAM. Thomas Richter _______________________________________________________________________________ So long, Thomas (September 2000)