Crunch - Revision history

Dexvertbot: /* Sample files */

2023-12-28T04:14:25Z

‎Sample files

Jsummers: /* Disambiguation */

2023-08-04T16:57:58Z

‎Disambiguation

JTN: fix rotted classiccmp.org links

2023-02-18T19:16:13Z

fix rotted classiccmp.org links

Sembiance: /* Sample files */

2022-06-15T20:41:26Z

‎Sample files

Jsummers: /* Software */

2021-04-29T15:56:07Z

‎Software

Jsummers: /* Disambiguation */

2021-03-14T18:35:25Z

‎Disambiguation

Jsummers at 15:52, 27 February 2021

2021-02-27T15:52:33Z

Jsummers at 15:43, 27 February 2021

2021-02-27T15:43:49Z

Jsummers: /* See also */

2021-02-25T18:33:22Z

‎See also

John e at 21:05, 14 January 2021

2021-01-14T21:05:19Z

@@ Line 72: / Line 72: @@
 * [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/cpm/ OAK CP/M archive] → .../*.?z?
 * Found in many [[LBR#Sample files|LBR]] files. Note that you may have to tell your LBR utility not to decompress them (e.g. <code>lbrate -n</code>).
-* https://telparia.com/fileFormatSamples/archive/crunch/
+* {{DexvertSamples|archive/crunch}}
 [[Category:File formats with too many extensions]]
 [[Category:CP/M]]

@@ Line 17: / Line 17: @@
 * The "crunched" compression methods used in [[ARC (compression format)|ARC]] format, though they are related.
 * [[Crunch-Mania]] - An Amiga file compression utility
-* [[Cruncher]] - An executable compression utility for DOS, by Ori Berger [http://cd.textfiles.com/simtel/simtel20/MSDOS/EXECOMP/CRUNCH10.ZIP]
+* [[Cruncher]] - An executable compression utility for DOS, by Ori Berger
-* CRUNCH - A compression optimization utility for DOS, by Bruce Gavin. It does not appear to have any native file formats. [http://cd.textfiles.com/20mnn/ARCHIVE/CRUNCH10.ZIP]
+* [[Crunch (Luck Martins)|Crunch]] - A file encryption utility for DOS, by Luck Martins ({{OldskoolDOSEXE}} → DOSEXE Executable Tools Pack → packers/crunch.14...)
-* Crunch - An old [[ARC (compression format)|ARC]] compression utility by Richard P. Byrne [http://cd.textfiles.com/rbbsv3n1/d86v/crunch.zip]
+* CRUNCH - A compression optimization utility for DOS, by Bruce Gavin [{{CdTextfilesURL|20mnn/ARCHIVE/CRUNCH10.ZIP}}]
-* CRUNCH - A PKARC automation utility by Chuck Zulker [http://cd.textfiles.com/megarom/megarom1/ARC_LBR/CRUNCH.ZIP]
+* Crunch - An old [[ARC (compression format)|ARC]] compression utility by Richard P. Byrne [{{CdTextfilesURL|rbbsv3n1/d86v/crunch.zip}}]
 == See also ==

@@ Line 47: / Line 47: @@
 == Specifications ==
-* The file header is described in the text file LZDEF20.DOC shipped with [http://www.classiccmp.org/cpmarchives/cpm/mirrors/oak.oakland.edu/pub/sigm/vol294/crunch20.lbr CRUNCH20.LBR].
+* The file header is described in the text file LZDEF20.DOC shipped with [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/sigm/vol294/crunch20.lbr CRUNCH20.LBR].
 ** An extracted copy is provided [[Crunch/LZDEF20.DOC|here]].
-* [http://www.classiccmp.org/cpmarchives/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/crunch.abs crunch.abs] - "Technical Abstract" by Steven Greenberg, 16 November 1986
+* [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/crunch.abs crunch.abs] - "Technical Abstract" by Steven Greenberg, 16 November 1986
 * [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/crunch.izf crunch.izf] → crunch.inf - Collected information about the format
@@ Line 59: / Line 59: @@
 * On CP/M (or emulators):
 ** The canonical tools were CRUNCH and UNCR. Possibly Greenberg's last version (Feb 1988) is v2.4:
-*** [http://www.classiccmp.org/cpmarchives/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/crunch24.lbr CRUNCH24.LBR]
+*** [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/crunch24.lbr CRUNCH24.LBR]
-*** [http://www.classiccmp.org/cpmarchives/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/crnch24s.lbr CRNCH24S.LBR] (source code)
+*** [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/crnch24s.lbr CRNCH24S.LBR] (source code)
-** The later LT31 deals with extracting from all of [[Squeeze]], [[Crunch]], [[CrLZH]] and [[LBR]] formats. Widely available in CP/M archives, e.g. [http://www.classiccmp.org/cpmarchives/cpm/mirrors/oak.oakland.edu/pub/cpm/arc-lbr/lt31.lbr LT31.LBR]
+** The later LT31 deals with extracting from all of [[Squeeze]], [[Crunch]], [[CrLZH]] and [[LBR]] formats. Widely available in CP/M archives, e.g. [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/cpm/arc-lbr/lt31.lbr LT31.LBR]
 ** crunch12.lbr - Crunch 1.2 - Possible sources: [http://gaby.de/ftp/pub/cpm/znode51/pcwworld/u111/user_0/crunch12.lbr], [https://www.worldofsam.org/products/fdos-disk-002-file-compressors-and-archivers]
-** [http://www.classiccmp.org/cpmarchives/cpm/mirrors/oak.oakland.edu/pub/sigm/vol294/crunch20.lbr crunch20.lbr] - Crunch 2.0
+** [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/sigm/vol294/crunch20.lbr crunch20.lbr] - Crunch 2.0
 ** [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/fcrnch11.lbr fcrnch11.lbr] - FCRUNCH v1.1 - An improved version of Crunch 2.x, by C.B. Falconer
 * {{CdTextfiles|megarom/megarom1/ARC_LBR/UNCR_DOS.ZIP|UNCR version "UNCR231"}} - Crunch v2 decompression source code by Frank Prindle. Package includes a DOS binary.
@@ Line 69: / Line 69: @@
 == Sample files ==
-* [http://www.classiccmp.org/cpmarchives/ftp.php?b=cpm/mirrors/oak.oakland.edu/pub/cpm/ OAK CP/M archive] → .../*.?z?
+* [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/cpm/ OAK CP/M archive] → .../*.?z?
 * Found in many [[LBR#Sample files|LBR]] files. Note that you may have to tell your LBR utility not to decompress them (e.g. <code>lbrate -n</code>).
 * https://telparia.com/fileFormatSamples/archive/crunch/

@@ Line 71: / Line 71: @@
 * [http://www.classiccmp.org/cpmarchives/ftp.php?b=cpm/mirrors/oak.oakland.edu/pub/cpm/ OAK CP/M archive] → .../*.?z?
 * Found in many [[LBR#Sample files|LBR]] files. Note that you may have to tell your LBR utility not to decompress them (e.g. <code>lbrate -n</code>).
 [[Category:File formats with too many extensions]]
 [[Category:CP/M]]

@@ Line 65: / Line 65: @@
 ** [http://www.classiccmp.org/cpmarchives/cpm/mirrors/oak.oakland.edu/pub/sigm/vol294/crunch20.lbr crunch20.lbr] - Crunch 2.0
 ** [http://cpmarchives.classiccmp.org/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/fcrnch11.lbr fcrnch11.lbr] - FCRUNCH v1.1 - An improved version of Crunch 2.x, by C.B. Falconer
 == Sample files ==

@@ Line 15: / Line 15: @@
 == Disambiguation ==
 Not to be confused with:
-* The "crunched" compression methods used in [[ARC (compression format)|ARC]] format. These methods are possibly related to those used by CP/M Crunch, but the file formats are not otherwise similar.
+* The "crunched" compression methods used in [[ARC (compression format)|ARC]] format, though they are related.
 * [[Crunch-Mania]] - An Amiga file compression utility
 * [[Cruncher]] - An executable compression utility for DOS, by Ori Berger [http://cd.textfiles.com/simtel/simtel20/MSDOS/EXECOMP/CRUNCH10.ZIP]

@@ Line 3: / Line 3: @@
 |subcat=Compression
 |extensions={{ext|?z?}}, {{ext|zzz}}
 }}
 :''This article is about the CP/M compressed file format. See the [[#Disambiguation|disambiguation section]] for other "Crunch" formats.''
@@ Line 10: / Line 11: @@
 Similar to [[Squeeze]], crunched files were signified in CP/M's 8.3 filename format by replacing the middle letter of the extension with Z (.?Z?), with the extension .ZZZ used for corner cases such as a blank extension.
-There are two versions of the compressed data format, and not all decompressors support both. The new format is apparently more common.
+There are two main versions of the compressed data format, and not all decompressors support both. The new (v2.x) format is apparently more common.
 == Disambiguation ==
@@ Line 30: / Line 31: @@
 == Format details ==
 Note that, as explained in the format documentation, the "filename" field contains not only the filename, but also extension data. If extension data exists, the filename extension is padded with spaces until it is exactly three characters long.
 In archives originating on CP/M systems, the high bit of each byte in the filename field may contain encoded CP/M file attributes. To extract the original filename, each byte should be masked with 0x7F.
 == Identification ==
@@ Line 41: / Line 49: @@
 * The file header is described in the text file LZDEF20.DOC shipped with [http://www.classiccmp.org/cpmarchives/cpm/mirrors/oak.oakland.edu/pub/sigm/vol294/crunch20.lbr CRUNCH20.LBR].
 ** An extracted copy is provided [[Crunch/LZDEF20.DOC|here]].
-** Note that the file header follows a similar/compatible structure to [[CrLZH]]. It was derived from [[Squeeze]], but bears only a little resemblance to it.
+* "Technical Abstract" by Steven Greenberg, 16 November 1986: [http://www.classiccmp.org/cpmarchives/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/crunch.abs CRUNCH.ABS]
-* FIXME: is the exact compression algorithm documented anywhere?
-** CRUNCH20.DOC shipped in CRUNCH20.LBR says: ''It embodies all of the concepts employed in the UNIX COMPRESS / ARC512 algorithm, but is additionally enhanced by a "metastatic code reassignment" facility. This is one of several concepts I am developing as part of an effort to advance data compression techniques beyond current performance limits. I believe this is the first time this principle has been proposed or implemented.''
-** See also "Technical Abstract" by Steven Greenberg, 16 November 1986: [http://www.classiccmp.org/cpmarchives/cpm/mirrors/oak.oakland.edu/pub/cpm/squsq/crunch.abs CRUNCH.ABS]
 == Tools ==

@@ Line 22: / Line 22: @@
 == See also ==
 * [[Squeeze]] - predecessor
 * [[CrLZH]] - successor
 * [[LBR]] - container
-* [[ZSQ (LZW compression)‎]] - Possibly related
+* [[ZSQ (LZW compression)‎]] - Similar format
 * [[Zoo Z format]] - Same file naming convention