Exabyte EXB-8505 8mm manual Physical Blocks

2 Recording Format

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:

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)

14 bytes of header information

Figure 2-8Physical block format for all logical formats (8200c or 8500/8500c physical track structure shown)

Note: The physical block header, ECC data, and physical block CRC data do not affect the data capacity of the tape.

May 1994	EXB-8205 and EXB-8505	2-9
	(Standard and XL)