(DLT) A magnetic tape drive format developed by DEC, based on the Digital Lempel Ziv 1 (DLZ1) compression algorithm. DLT drives are capable of 2.5 megabytes per second transfer rates with compression, and 1.25M bytes/s uncompressed. DEC's tests have achieved about 1 gigabyte in 12 minutes. One of the available drives has a 10GB raw/20GB compressed capacity on a single cartridge.
The Lempel-Ziv compression type used maps variable length input strings to variable length output symbols. During compression, the algorithm builds a dictionary of strings which is accessed by means of a hash table. Compression occurs when input data matches a string in the table and is replaced with the output symbol.
(22 Feb 1995)