Difference between revisions of "Archiver"
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The archive file may be compressed to save space on the storage medium. The compression used in ARCHIVER is [http://en.wikipedia.org/wiki/Lempel-Ziv-Welch Lempel-Ziv-Welch], also known as LZW. The implementation uses a variable bit count, starting with 9 bits, then increasing up to 12 bits. When all entries are used up, it restarts with 9 bits. | The archive file may be compressed to save space on the storage medium. The compression used in ARCHIVER is [http://en.wikipedia.org/wiki/Lempel-Ziv-Welch Lempel-Ziv-Welch], also known as LZW. The implementation uses a variable bit count, starting with 9 bits, then increasing up to 12 bits. When all entries are used up, it restarts with 9 bits. | ||
Compressed archives are stored in '''Int/Fix 128''' format. | |||
Both variants - compressed and uncompressed - share the same data structures. The compressed variant is simply an LZW compression applied to the uncompressed archive file. | |||
Revision as of 19:42, 28 December 2012
Barry Boone's utility ARCHIVER is the common tool to package files on the TI-99 and Geneve systems. Tim Tesch modified it for use with hard disks, in particular by changing the way the source directory is specified (you can provide a complete pathname).
Uncompressed archive
Uncompressed archives contain the contents and metadata of a set of files in a single archive file. Uncompressed archives are stored in Dis/Fix 128 format.
Compressed archive
The archive file may be compressed to save space on the storage medium. The compression used in ARCHIVER is Lempel-Ziv-Welch, also known as LZW. The implementation uses a variable bit count, starting with 9 bits, then increasing up to 12 bits. When all entries are used up, it restarts with 9 bits.
Compressed archives are stored in Int/Fix 128 format.
Both variants - compressed and uncompressed - share the same data structures. The compressed variant is simply an LZW compression applied to the uncompressed archive file.