Commodore 1581 - Page 15

1581 SOFT ERROR TEST
VERSION 1.5.1
6. TRACK, ERRORS, FIRST PASS RETRIES
This listing breaks down all Encountered Errors on a Per Track Basis.
* A Defective Diskette is indicated by Errors Concentrated on the
Same Track or Adjacent Tracks
* Displayed Only if at Least One Error was encountered
7. ERROR TYPE, OPERATION, ERRORS
This listing breaks down Total Errors according to Type of Error,
Operation Being Performed when the error occurred and Number of
Encountered Errors per type as follows ....
* HEADER BLOCK NOT FOUND
* The Header Block Identifier could not be found
* NO SYNC CHARACTER
* A Sync Mark, (10 or More Consecutive 1 Bits), on a given track could
not be found within a predetermined amount of time and a Time Out
has occurred
* DATA BLOCK NOT FOUND
* A Decoded 8 Bit Byte read from the diskette did not compare to a
Present Block Identifier
* DATA BLOCK CHECKSUM ERROR
* The Calculated Checksum of a 256 Byte Data Block did not match the
Actual Checksum Read from the diskette
* VERIFY ERROR AFTER WRITE
* The Data just Written to a sector of the diskette when Read Back,
does not verify with Data Stored in Disk Memory
* WRITE PROTECT ERROR
* A Write Operation to the diskette cannot be performed due to ....
* Write-Protect Tab Open on the Diskette
* Defective Write-Protect Sensor
* HEADER CHECKSUM ERROR
* The Header Checksum, Stored in Disk Memory, when EORed with an
Independent Checksum does not compare
* ID MISMATCH ERROR
* The Disk IDs, Read from the Header Block, did not compare with
the Disk IDs Stored in Disk Memory.
* Data Block Checksum Errors are normally caused by Random Electrical
Noise and will usually Recover in One (1) Retry
OPERATION
* READ - Data is Read and Verified against Expected Data
* WRITE - Data is Written, Stored in Disk Memory, Read Back and
Compared to Disk Memory Data
* SEEK - The Read/Write Head is moved to a Predetermined Track
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