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5.4.1
WRITE ERRORS
If an error occurs during a Write operation, it will be detected on the next diskette rotation by
doing a Read operation commonly called a "Write Check." To correct the error, another Write and
Write Check operation must be done. If the Write operation is not successful after five attempts,
error correction should be attempted on another track. If the error persists, the diskette should be
considered defective and be discarded or re-initialized.
5.4.2
READ ERRORS
Most errors that occur will be "soft" errors; that is, by performing an error recovery procedure,
the data will be recovered.
Soft errors are usually caused by any of three conditions:
A.
Airborne contaminants that pass between the R/W head and the
diskette surface. These contaminants will generally be removed by
the cartridge self-cleaning wiper.
B.
Random electrical noise which usually lasts for a new microseconds.
C.
Small defects in the written data and/or track, not detected during
the Write operation and which may cause a soft error during a Read
operation.
5.4.2.1
Soft Error Recovery Procedure. To recover soft errors, the following procedure is
recommended:
A.
Reread the track five times or until such time as the data are recovered.
B.
If data are not recovered after performing step A, access the head to
the adjacent track in the same direction previously moved, then return
to the desired track and repeat step A.
C.
If data are not recovered, the error is not recoverable.
5.5
ALIGNMENT DISKETTE
The Alignment Disk, (Dysan PIN 282 or 224/2) is available from Dysan Corp., Santa Clara, Calif-
ornia. This special tool is used to perform the following alignments and adjustments:
5-3
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