User's Guide

Chapter 3 Emulated DLT7000 SCSI Commands
Read Buffer (3Ch)
Quantum DX-Series Software Interface Guide 237
Table 186 READ
BUFFER Header -
Field Descriptions
Data Mode 3
In this mode, the DATA IN phase contains only buffer data.
Descriptor Mode 3
In this mode, a maximum of four bytes of READ BUFFER descriptor
information is returned. The tape drive returns the descriptor
information for the buffer specified by the Buffer ID. In this mode, the
drive does not reject the valid Buffer IDs with a CHECK CONDITION
status, but returns all zeros in the READ BUFFER descriptor.
The Offset Boundary is 12 (0Ch), indicating that buffer offsets should be
integral multiples of 4 K.
Table 187 READ
BUFFER Descriptor -
Data Format
Bit/Byte 7 6 5 4 3 2 1 0
0
1-3
Field Name Description
Available
Length
This field specifies the total number of data bytes
available in the target’s buffer. This number is not
reduced to reflect the allocation length, nor is it
reduced to reflect the actual number bytes written
using the WRITE BUFFER command. Following the
READ BUFFER header, the target transfers data
from its data buffer.
Offset Boundaries (0Ch)
(MSB)
Buffer Capacity
(LSB)
Tech Tip: Read and Write buffer is currently not implemented.