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COMMON COMMAND SET AND DISK OPERATION
MVME147 SCSI Firmware: Winchester Disk Parameters.
Before formatting a Winchester disk, the MVME147 SCSI firmware sends a mode select command for read/write error recovery parameters (page 1) to the controller. Below is the command descriptor block for the mode select command:
Mode Select Command CDB
| BYTE OFFSET | VALUE | COMMENTS | |
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0 | 15 | Command code | ||
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1 | 10 | LUN = 0, PF = 1, SP = 0 | ||
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2 | 00 | Reserved | ||
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3 | 00 | Reserved | ||
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4 | (Note) | Parameter list length | ||
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5 | 00 | Control byte: no link, no flag | ||
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NOTE: | If all of the parameters match or are not changeable, |
| only the mode select header and block descriptor is |
| sent, and the parameter list length is be $0C. |
| If a parameter is changed based on the current, |
| changeable, and the packet parameter, the entire page |
| 1 including the mode select header and the block |
| descriptor is sent, and the parameter list length is $18. |
The first twelve bytes that are transferred during the DATA OUT phase for the mode select command make up the mode select header, and the block descriptor which is described below:
Mode Select Header and Block Descriptor
BYTE OFFSET | VALUE | COMMENTS |
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| Mode Select Header |
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0 | 00 | Reserved |
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1 | 00 | Media type |
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2 | 00 | Reserved |
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