Short: A compressing disk device v37.4; uses XPK
Uploader: rhialto@mbfys.kun.nl (Olaf Seibert)
Type: util/pack

Overview
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   `xpkdisk.device' is an exec-style device that looks like
trackdisk.device and similar disks. The difference is that it compresses
its data and stores it in multiple files in an existing filesystem.

   * Now uses a hierarchical track naming scheme for faster access!
     See Upgrade on what to do if you are upgrading from the old naming
     scheme.

   * Now behaves better in cace of threatening lack of disk space.

   * Now handles read-only media.

   It uses the XPK (eXternal PacKer) standard to do the actual
compression.  This has many advantages:

   * You can choose which compression is most effective for your
     purpose. For one disk, you might want a very tight compression
     that is slow, for another you may prefer a faster but less
     efficient compression.

   * As soon as another XPK library is released, you can use it for your
     compressed disk(s).

   * Because each track is a standard XPK-compressed file, you can use
     the normal XPK utilities to uncompress your data, should you wish
     to do so.

   * You can change the compression type of a disk on-the-fly. All
     already compressed data remains perfectly usable, but upon
     re-compression your new choice will be used.

   * You can even manually decompress and recompress your disk (when
     xpkdisk is not accessing it, of course) with another compression
     method.