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Zip/Window Registry Key WINDOW PARAMETER Zip/Window DEFAULT 16384 DESCRIPTION The DEFLATE algorithm compresses a file by locating combinations of bytes or characters that repeat. The redundancy is removed and replaced by an efficient pointer to the original grouping. The most efficient compression then would remove any and all redundant groups from an entire file. This is certainly possible for small files. With large files the pointers need to address data further and further away. As the distance grows so do the pointers and efficiency suffers. The solution is to limit the distance using a sliding window through the file. By default JANOS uses a 16KB (16384 byte) sliding window. This Registry key may be used to adjust the window from a minimum of 2KB (2048) to a maximum of 32KB (32768). In practice there should be no reason to alter this setting. A change in this setting affects the very next compression that is performed. DEPTH PARAMETER Zip/Depth DEFAULT 256 DESCRIPTION With each successive character in a file the compressor looks back over the sliding window for groupings where replacement by pointer would provide the greatest compression. This is a time consuming endeavor. As a tradeoff the JANOS routine employs a queue of likely targets in the window for each unique character. This reduces the search effort and the time it takes to perform the compression. By default the search queue depth is set at 256 entries. Values may range from a minimum of 16 to a maximum of 1024. In practice there should be no reason to alter this setting. A change in this setting affects the very next compression that is performed. SEE ALSO HELP Topics: ZIP, COMPRESSION [/flash/manpages/registry.hlp:3847]