Specifications

ATAPI For Streaming Tape QIC-157 Rev B
58
6.8.6.39.Tape Capacity Page Code 31h
Table 6-28 Tape Capacity Page Code 31h
Bit
Byte
7 6 5 4 3 2 1 0
0 Page Code (31h)
1 Reserved
2 (MSB) Page Length (32)
3 (LSB)
4 (MSB) Parameter Code 1h
5 (LSB)
6 0 (DU) 1 (DS) 0 (TSD) 0 (ETC) 0 (TMC) Reserved 0 (LP)
7 Parameter Length (4)
8 (MSB) Remaining Capacity, Partition 0
11 (LSB)
12 (MSB) Parameter Code 2h
13 (LSB)
14 0 (DU) 1 (DS) 0 (TSD) 0 (ETC) 0 (TMC) Reserved 0 (LP)
15 Parameter Length (4)
16 (MSB) Remaining Capacity, Partition 1
19 (LSB)
20 (MSB) Parameter Code 3h
21 (LSB)
22 0 (DU) 1 (DS) 0 (TSD) 0 (ETC) 0 (TMC) Reserved 0 (LP)
23 Parameter Length (4)
24 (MSB) Maximum Capacity, Partition 0
27 (LSB)
28 (MSB) Parameter Code 4h
29 (LSB)
30 0 (DU) 1 (DS) 0 (TSD) 0 (ETC) 0 (TMC) Reserved 0 (LP)
31 Parameter Length (4)
32 (MSB) Maximum Capacity, partition 1
35 (LSB)
For single partition tapes, Partition 1 values shall always be zero.
The Remaining Capacity for non-current partitions shall be the same as the Maximum Capacity for
that partition.
The Maximum Capacity values are valid only after the load operation is completed. Remaining
Capacity is valid after a SPACE to EOD, WRITE, or WRITE FILEMARK and DSC bit is set.
Following LOCATE, REWIND, SPACE Block or Filemark, READ, LOAD and MODE SELECT
the Remaining Capacity reflects a progress value as a ratio of Remaining and Maximum
Capacity.
Capacities are multiplied by 1024 to determine the number of bytes. These values are estimates and,
where compression is implemented, they assume a 1:1 compression ratio and allow for worst-case
write retry. Allowances for frame grouping, system log areas, EOD and EOP areas, and headers are
not included in these capacity values to ensure a conservative estimate.