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File Format
Name CrLZH
Extension(s) .?y?, .yyy
CrLZH (often referred to as just "LZH", but not to be confused with the format used for .lzh files) was a method of compressing single files used on CP/M, devised by Roger Warren in the late 1980s. It came later than Squeeze and Crunch and generally achieved better compression than those formats. LZH files occurred standalone and as members in LBR archives. The underlying compression is based on that used by LHArc.

Similar to Squeeze and Crunch, these files were signified in CP/M's 8.3 filename format by replacing the middle letter of the extension with Y (.?Y?), with the extension .YYY used for corner cases such as a blank extension.


  • CFX (DOS/Unix)
  • lbrate by Russell Marks, c. 2001 (Unix, GPL2)
  • On CP/M (or emulators):
    • The original tools were those in the CRLZH distribution, e.g. CRLZH20.LBR
    • The later LT31 deals with extracting from all of Squeeze, Crunch, CrLZH and LBR formats. Widely available in CP/M archives, e.g. LT31.LBR


  • Some format information is in LZHREL.DOC shipped with CRLZH20.LBR
    • An extracted copy is provided here.
    • Note that the file header follows a similar/compatible structure to Squeeze and Crunch.
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