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Diskette Format and Write Combined to Increase Performance

IP.com Disclosure Number: IPCOM000043689D
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Baker, ED: AUTHOR [+2]

Abstract

A technique is described whereby formatting and writing on double-sided diskettes, used with the IBM 4966 attached to an IBM Series/1 processor, may be accomplished in five revolutions instead of the normal nine revolutions. The concept is particularly useful where high volume diskette duplication is required. Under the current nine revolution operation to "Seek, Format and Write" a double-sided diskette, the following nine revolutions are required: 1. Seek to Cylinder 2. Format Side 0 3. Verify CRC (Cyclic Redundancy Check) Side 0 4. Write Data Side 0 5. Verify Data Side 0 6. Format Side 1 7. Verify CRC Side 1 8. Write Data Side 1 9. Verify Data Side 1 By implementing a microcode patch and making a small card wiring change, only five revolutions are required as follows: 1. Seek to Cylinder 2.

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Diskette Format and Write Combined to Increase Performance

A technique is described whereby formatting and writing on double-sided diskettes, used with the IBM 4966 attached to an IBM Series/1 processor, may be accomplished in five revolutions instead of the normal nine revolutions. The concept is particularly useful where high volume diskette duplication is required. Under the current nine revolution operation to "Seek, Format and Write" a double-sided diskette, the following nine revolutions are required: 1. Seek to Cylinder 2. Format Side 0 3. Verify CRC (Cyclic Redundancy Check) Side 0 4. Write Data Side 0 5. Verify Data Side 0 6. Format Side 1 7. Verify CRC Side 1 8. Write Data Side 1 9. Verify Data Side 1 By implementing a microcode patch and making a small card wiring change, only five revolutions are required as

follows: 1. Seek to Cylinder 2. Format and Write Side 0 3. Verify with Data Compare Side 0 4. Format and Write Side 1 5. Verify with Data Compare Side 1

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