Sony SDX-800V/R manual Sequential-Access Density Codes Code Value

MODE SELECT										6.Command Specification
			Table 6-36: MODE SELECT parameter list
Bit	7	6		5		4		3	2	1	0
Byte
0							Reserved
1							Reserved
2	Reserved		Buffered Mode (001b)						Speed (00h)
3					Block Descriptor			Length (08h)
4						Density Code
5	(MSB)				Number of Blocks (00 00 00h)
6
7											(LSB)
8							Reserved
9	(MSB)					Block Length
10
11											(LSB)

Buffered Mode: Buffered Mode is the mechanism by which the drive implements Immediate Reporting on WRITE commands.

If the field is ZERO, then the drive does not report a GOOD status on WRITE commands until the data blocks are actually written to tape (not support).

If the Buffered Mode field is one, then the drive reports GOOD status on WRITE commands as soon as the data block has been transferred to the buffer. This field should be set to ONE.

Speed: The drive only supports one speed, the default speed. Because of this, this field must be set to ZERO. Any other value will cause a CHECK CONDITION status with an ILLEGAL REQUEST sense key is returned.

Block Descriptor Length: This specifies the length in bytes of all the block descriptors. Since the drive only allows one block descriptor, this value must be eight. Any other value will cause a CHECK CONDITION status with an ILLEGAL REQUEST sense key to be returned.

Note: The block descriptor specifies the media characteristics for the SDX drive. The block descriptor contains the density code, number of blocks and block length fields.

Density Code: The supported values for the density code field are defined in the following table.

Note: 00h - Default: The use of the word “Default” is SCSI specific. It instructs the drive to use its default or only density.

Table 6-37: Sequential-Access Density Codes

Code Value	Code Value
00h	Default Format
30h	AIT-1	Format
31h	AIT-2	Format
32h	AIT-3	Format
38h	AIT-E Turbo Format
39h	AIT-1 Turbo Format
3Ah	AIT-2 Turbo Format
3Bh	AIT-3Ex	Format
7Fh	No change from previous density

Number of Blocks: A MODE SENSE field which will be returned as ZERO, indicating that all of the remaining logical blocks on the media will have the medium characteristics specified by the block descriptor, or until a subsequent MODE SELECT command changes those parameters. This field must be set to ZERO on a MODE SELECT otherwise a CHECK CONDITION status will be returned with an ILLEGAL REQUEST sense key.

SONY AIT-3Ex drive SDX-800V series Ver.1.1 6-39