Difference between revisions of "Archiver"

From Ninerpedia
Jump to navigation Jump to search
m (moved Archiver format to Archiver: Most likely search term. Article to be added to later. Will create a redirect from the narrow prior article title.)
(No difference)

Revision as of 15:20, 2 January 2015

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.