Table 4-26. Block Id Format - Fujitsu M2488 Product Manual

M2488 PRODUCT GUIDE
Table 4-25. LOCATE Field Description (Continued)
BYTE BIT VALUE
1 2
3-6
8
The high speed locate is at 4 meters per second. High speed positioning will not occur if the Block
Address Type (BT) bit is 0. It will also not occur if the BT bit is 1 and the Wrap and Physical ref-
erence fields of the Block address are both 0.
BYTES 7
0 Wrap
1 Format Code
2
3
April 1997
0 The Block Address Type (BT) is interpreted as a logical block address.
The first filemark or data block on tape is assigned logical block address 0;
logical block addresses increase by 1 for each data block and filemark
thereafter. The maximum Logical block address is 3FFEFFh.
1 The Block address is interpreted as a device specific block address. For
this tape unit these addresses are also known as Block IDs. The Block ID
consists of four fields: Wrap, Physical reference, Format code and Logical
block position. The format of a Block ID is shown in Table 4-26.
Block Address
The Partition field specifies the target position.

Table 4-26. Block ID Format

6 5 4
Logical Block Position (middle significant bits)
Logical Block Position (LSB)
CG00000-011503 REV. A
TAPE UNIT SCSI COMMANDS
DESCRIPTION
BITS
3 2
Physical Reference
Logical Block Position (MSB)
1 0
4-29