Справочник Пользователя для Exabyte EXB-8505 8mm
Physical Blocks
For all three physical track formats, each physical track contains eight
physical blocks. A physical block can contain user data or other
information. As shown in Figure 2-8, a physical block containing user
data includes the following information:
physical blocks. A physical block can contain user data or other
information. As shown in Figure 2-8, a physical block containing user
data includes the following information:
2 bytes of cyclic redundancy check (CRC) data
400 bytes of error correction code (ECC) data
1,024 bytes of uncompressed user data or 2,048 of compressed
user data (assuming a 2:1 compression efficiency)
user data (assuming a 2:1 compression efficiency)
14 bytes of header information
Note:
The physical block header, ECC data, and physical block CRC
data do not affect the data capacity of the tape.
data do not affect the data capacity of the tape.
Figure 2-8 Physical block format for all logical formats (8200c or 8500/8500c physical track structure shown)
May 1994
EXB-8205 and EXB-8505
2-9
(Standard and XL)
2 Recording Format