Reference Guide

Chapter 4 SCSI Commands
VERIFY Command (13h)
DLT-S4 Interface Reference Guide 334
VERIFY Command (13h) 4
The VERIFY command directs the tape drive to verify one or more blocks
beginning with the next block on the tape. The drive verifies both CRCs
and EDCs.
Figure 169 VERIFY Command
Descriptor Block—Data Format
Table 189 VERIFY Command
Data — Field Descriptions
Bit
Byte
7 6 5 4 3 2 1 0
0 Operation Code (13h)
1 Reserved Immed BytCmp Fixed
2 — 4
(MSB)
Verification Length
(LSB)
5 Control
Field Description
Immed Immediate. When set to 1, the
VERIFY command completes, provided it has begun
processing, before the drive performs any tape medium movement.
BytCmp Byte Compare. Must be set to 0.
Fixed Specifies whether the drive is to verify fixed-length or variable-length blocks.
When set to 0, variable-block mode is requested. The drive verifies a single block with
the Verification Length specifying the block size.
When set to 1, the Verification Length specifies the number of blocks the drive is to
verify. This is valid only if the drive is currently operating in fixed-block mode.
Verification
Length
Specifies the amount of data to verify, in blocks or bytes, as indicated by the Fixed field.