User's Guide

Chapter 3 Emulated DLT7000 SCSI Commands

Mode Select (6 /10) (15h / 55h)

180 Quantum DX-Series Software Interface Guide

Mode Page Descriptors 3

Following the MODE SELECT command’s Mode Parameter Block

Descriptor are the MODE SELECT pages, each of which sets a different

device parameter. Each mode page has a 2-byte header that identifies the

page code and indicates the number of bytes in that page.

Table 135 MODE

SELECT Page

Descriptor - Data

Format

Bit/Byte 7 6 5 4 3 2 1 0

2-n

Number of

Blocks

This MODE SENSE field is sent = 0, indicating that

all of the remaining logical blocks on the tape will

have the medium characteristics specified by the

block descriptor.

Block

Length

This field specifies the length, in bytes, of each

logical block transferred over the SCSI bus. A block

length of 0 indicates that the length is variable

(specified in the I/O command). Any value other

than 0 indicates the number of bytes per block to

use for READ, WRITE, and VERIFY commands that

specify a “fixed” bit of 1 (i.e., fixed block mode)

which also causes the transfer length in the

command descriptor block to be defined as a block

count. If fixed bit is not equal to 1, this field is

ignored.

PS(0) 0 Page Code

Additional Page Length

Page-Defined or Vendor Unique Parameter List

Field Name Description