Data Compression - Freecom TAPEWARE AIT-250I Specification

2.Specification

2.6. Data Compression

The tape capacity is increased by compressing data prior to writing it to the tape. Data compression is a well
established technology for reducing the number of bits used to represent data in order to improve data transfer rate
as well as reduce the amount of storage space consumed by the data. The compression ratio depends on the source
file type. The SDX-250V uses the ALDC Data Compression algorithm. ALDC is ECMA standard data compression
algorithm. (ECMA-222) The Data Compression control page allows the host computer to enable data compression
and decompression and also configure the way in which the drive responds to compressed/uncompressed data
boundaries on the tape. The AIT-E Turbo Format allows both compressed and uncompressed data to reside on the
same tape.
The Sony SDX-250V has a DIP switch to disable the Data Compression/ Decompression. After power-on reset with
this DIP switch set, both data compression and data decompression are disabled However, a MODE SELECT
command can override the setting of this DIP switch. After power-on reset without this DIP switch set, both data
compression and data decompression are enabled. (See clause 3.1.5)
2-10 SONY AIT-E Turbo drive SDX-250V series Ver.1.0