IBM System/7 Functional Characteristics - All about the IBM 1130 ...

Track Initialization ProceduresThe following procedures are recommended for track initialization programs used withthe 5022 Disk Storage Module. They must be performed for each disk (upper or lower)to format the tracks and analyze the condition of the disk surface. (Steps 2 to 5 must beperformed twice for each cylinder—once for the upper track and once for the lowertrack.)OperationDescription1. Read sector ID Determine that the track has not been previously flagged.(This step need not be performed when initializing a prevouslyunused disk.)2. Format track Write address marks, sector identifiers, and gaps on the track.3. Read verify Check all the sectors to ensure that data can be recoveredcorrectly. If an error occurs, go to step 10.4. Write data Write on each sector with a data word of hexadecimal 5555.5. Read verify Check all the sectors to ensure that data can be recoveredcorrectly. If an error occurs, go to step 10.6. Proceed If both tracks in the cylinder are formatted, seek to thenext cylinder and repeat steps 2 through 5. If both tracksare not formatted, repeat steps 2 through 5 for the othertrack in this cylinder.7. Repeat Perform steps 2 through 6 until all tracks have been processed.8. Read sector ID Read a sector ID on all tracks to check fo- seek errors. Aseek error during a format track operation causes two differenttracks to contain the same identifiers or the identifiersfor one track to be missing.If a seek error occurred during the formatting operation,repeat steps 1 through 7.9. Proceed Perform steps 2 through 8 at least once to complete theinitialization procedure.10. Error handling If an error occurs, analyze the ISW and ISWEX. If a missingaddress mark or file data check occurs, retry a read verifycommand at least 10 times. On the first unsuccessful retrythat indicates a missing address mark or file data check, flagthe track as defective and go to step 11. If all 10 retries aresuccessful, proceed with the initialization procedure fromthe point at which it was interrupted.For any error other than missing address mark or file datacheck, follow the normal error recovery procedures describedlater under "Suggested Error Recovery Procedures."11. Assign track Alternate tracks must be proved reliable by steps 2 through5 before they are used as alternates.12. Format track Write sector identifiers on the defective track with the flagbits set to 1 and 0, respectively, and the cylinder and sectorvalues of the alternate track. A defective alternate trackshould be formatted with its own address and flag bits bothset to 1.13. Read sector ID Read a sector ID from the defective track just formatted. Ifthe address of the alternate track cannot be recovered, thedisk must be repaired unless this is an alternate track.