Apple Disk II Technical Procedures

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D. DRIVE SPEED ADJUSTMENT — THE D-SPEED TESTIf a drive will not boot disks, or gives many I/O error messages, orproduces diskettes that other drives cannot read, it may be spinningtoo quickly or too slowly. This causes its reading and writing to beincompatible with that of other drives. The D-Speed test checks thespeed of the drive so that you can adjust it to within standardtolerance.The test works by writing a pattern to a scratch diskette and thenreading it. If the test will not run, you may be using a defectivescratch diskette; try another. If the test still will not run, thewrite-protect switch may be stuck in protect mode (see Write-ProtectSwitch Adjustment). If the test still will not run, replace the AnalogCard with a known good one.Adjusting the Speed:1. Power down. Disconnect the customer's drive from his Apple.2. Remove the cover of the customer's drive.3. Using a known good interface card, connect the customer's drive tothe DRIVE 2 position and a known good drive to the DRIVE 1position. (Make sure all the pins are in the proper holes).4. Using a known good Apple ][, make sure power is down and theninsert the interface card into slot 6.5. Place the Disk Alignment Aid diskette in the known good drive andboot it.6. When the menu comes up, SET TARGET DISK will be highlighted.Accept it by pressing A.7. Set target for slot 6, drive 2, by pressing S, A, A. Press .8. Select D-SPEED test (press S, S, S, A).9. The screen will warn you that the test will write on the diskette.Put a scratch diskette in the target drive and press A again.NOTE: At this point, the screen should show a scale with -100 onthe left and +100 on the right, with a marker indicating the actualspeed of the drive. The acceptable range is + or - 26. If the D-Speed is outside this range, proceed with the adjustment.10. Look at the BACK of the drive mechanism. Locate the Motor ControlCard, mounted on edge, and note the small trimpot with ascrewdriver adjustment on the side (Figure 4, #1).NOTE: Do not confuse this with the trimpot(s) on the analog card!disk ][ adjustments rev. 8-31-82 page 2.8
11. Set the speed so that it indicates between -5 and 0. Press ,A, A. Allow the drive to run for 128 passes and confirm that theaverage D-speed is between -5 and 0. Readjust if necessary. Veryerratic speed can sometimes be corrected by cleaning the pulleyswith alcohol.disk ][ adjustments rev. 8-31-82 page 2.9
Page 1: DISK ][ TECHNICAL PROCEDURESTABLE O
Page 5 and 6: A. REMOVING THE DISK DRIVE COVER1.
Page 7 and 8: B. REPLACING THE DISK DRIVE CABLERe
Page 9 and 10: C. REPLACING THE ANALOG CARDRemovin
Page 11 and 12: D. REPLACING THE COLLET HUBRemoving
Page 13 and 14: Disk ][ Technical ProceduresSection
Page 15 and 16: A. COLLET HUB ADJUSTMENTIf the disk
Page 17: B. DRIVE DOOR ADJUSTMENTWhen the di
Page 22 and 23: disk ][ adjustments rev. 8-31-82 pa
Page 25: Disk Drive Technical ProceduresSect
Page 28 and 29: B. AMPLITUDE TESTThe amplitude test
Page 30 and 31: 13. After the test signal has been
Page 32 and 33: Disk Safety Check5. Set the oscillo
Page 34 and 35: 16. Turn the oscilloscope's trigger
Page 36 and 37: The Test:7. Boot the Calibration (o
Page 38 and 39: E. HEAD RADIAL ADJUSTMENTThe Head R
Page 40 and 41: The Test:13. Change the oscilloscop
Page 42 and 43: ALPS Drive adjustment:23. Adjust th
Page 44 and 45: F. COMPARATOR OFFSET ADJUSTMENT:The
Page 46 and 47: 13. After the test signal has been
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Page 56 and 57: Disk ][ Analog Board rev. Jun 84 Pa
Page 62 and 63: Disk ][ Analog Card rev. Jun 84 Pag
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Apple Disk II Technical Procedures

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