Browse Prior Art Database

Floppy Disk Tester

IP.com Disclosure Number: IPCOM000044154D
Original Publication Date: 1984-Nov-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Johnson, SD: AUTHOR [+2]

Abstract

To detect defects in floppy disks, the diskette under test is read by a diskette drive that can indicate the angular location of the defect and stop the disk rotation rapidly before the diskette cleaning liner removes, from the disk, the debris causing the defect. In a test, the diskette 11 (Fig. 2) is loaded into drive 10. In Fig. 1, the disk spindle drive pulley 12 is marked so that optical sensor 14 can detect reference mark 15 during rotation of the disk. When a defect is detected, the motor 13, which drives the spindle via belt 16 and pulley 12, is immediately turned off. At the same time, the test electronics (not shown) indicates the time from the angular reference point to the defect. The logic in Fig. 3 is used to turn spindle drive motor 13 off rapidly.

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Floppy Disk Tester

To detect defects in floppy disks, the diskette under test is read by a diskette drive that can indicate the angular location of the defect and stop the disk rotation rapidly before the diskette cleaning liner removes, from the disk, the debris causing the defect. In a test, the diskette 11 (Fig. 2) is loaded into drive 10. In Fig. 1, the disk spindle drive pulley 12 is marked so that optical sensor 14 can detect reference mark 15 during rotation of the disk. When a defect is detected, the motor 13, which drives the spindle via belt 16 and pulley 12, is immediately turned off. At the same time, the test electronics (not shown) indicates the time from the angular reference point to the defect. The logic in Fig. 3 is used to turn spindle drive motor 13 off rapidly. At each access operation or upon reset, OR 20 passes a signal that loads an initial count into counter 22. This signal from OR 20 also sets latch 24. When latch 24 is set, the inhibit signal for gate 26 is not present and gate 26 passes the Motor On signal to the spindle motor controls. Each time the test electronics detects an error, counter 22 is counted down one count. If the count reaches zero before the next access, counter 22 resets latch 24. Latch 24 raises the inhibit (INH) line, and gate 26 no longer passes the Motor On signal. Thus, after a prescribed number of errors set by the initial count have occurred, spindle motor 13 is shut down. From the time difference between the s...