2.Specification
2-10 SONY AIT-5 drive SDX-1100V series Ver. 1.0
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-1100V 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-3, AIT-3Ex, AIT-4 and AIT-5 Format allows both
compressed and uncompressed data to reside on the same tape.
The Sony SDX-1100V 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 3.1.4)