TERSE - Revision history

Jsummers: /* Related formats */

2023-12-26T15:26:19Z

‎Related formats

Eiim: Add more infobox data

2023-09-15T01:35:20Z

Add more infobox data

Eiim: Add more detail, mostly from open-source repo.

2023-09-14T01:49:24Z

Add more detail, mostly from open-source repo.

Eiim: Mention PACK/SPACK

2022-11-04T19:06:11Z

Mention PACK/SPACK

SJK: /* Software */

2021-01-02T12:53:37Z

‎Software

SJK: /* Software */

2021-01-02T12:53:22Z

‎Software

SJK at 12:48, 2 January 2021

2021-01-02T12:48:41Z

Jsummers: Created page with "{{FormatInfo |formattype=electronic |subcat=Compression |released=1984? }} '''TERSE''' is a data compression format used on OS/2. More research is needed to understand the sc..."

2020-07-10T12:21:47Z

Created page with "{{FormatInfo |formattype=electronic |subcat=Compression |released=1984? }} '''TERSE''' is a data compression format used on OS/2. More research is needed to understand the sc..."

New page

{{FormatInfo
|formattype=electronic
|subcat=Compression
|released=1984?
}}
'''TERSE''' is a data compression format used on OS/2.

More research is needed to understand the scope of what TERSE was used for, and how many versions of it there are.

It can at least be used for single-file compression, as is done by the Advantis software listed below. This file format does not appear to have a conventional filename extension – compressed files may keep their original name.

== Identification ==
At least some TERSE-compressed files start with bytes {{magic|05 01 01 00}}.

== Related formats ==
The [[ZIP]] format documentation (APPNOTE) lists two "TERSE" compression methods:

10 - PKWARE Data Compression Library Imploding (old IBM TERSE)
18 - File is compressed using IBM TERSE (new)

So, apparently, [[PKWARE DCL Implode]] is closely related to TERSE.

== Software ==
* TERSE utility by Michael Nagy and Advantis
** [http://thorntonzone.com/afp/Mainframe/TERSE%20%28IBM%20mainframe%20compression%29/image-list.php?showsource=1] → [http://thorntonzone.com/afp/Mainframe/TERSE%20%28IBM%20mainframe%20compression%29/tersepc.zip tersepc.zip] - Collection of binaries for several platforms
** [https://www.sac.sk/download/pack/terse.zip terse.zip] - OS/2 binaries
** [https://www.ibm.com/support/knowledgecenter/SSB27H_6.2.0/fa2ut_part3_terse.html IBM Knowledge Center: Terse Utility]

== Links ==
* [[Wikipedia:Terse (file format)|Wikipedia article]]

[[Category:IBM]]
[[Category:OS/2]]

@@ Line 26: / Line 26: @@
 So, apparently, [[PKWARE DCL Implode]] is closely related to TERSE. It's possible that this distinction is or is related to the PACK/SPACK distinction in the file type.
-[[BSQ (encoding)|BSQ]] is apparently related to TERSE. [https://archive.org/details/bsq-v-2.0]
+[[BSQ (W1GOH)]] is apparently related to TERSE.
 == Software ==

@@ Line 3: / Line 3: @@
 |subcat=Compression
 |released=1984?
 }}
 '''TERSE''' is a data compression format used on OS/2, and on IBM mainframes. It is still in regular use on IBM mainframes to this day.

@@ Line 8: / Line 8: @@
 More research is needed to understand the scope of what TERSE was used for, and how many versions of it there are.
-It can at least be used for single-file compression, as is done by the Advantis software listed below. This file format does not appear to have a conventional filename extension – compressed files may keep their original name.
+There appear to be two compression algorithms, called PACK and SPACK. There are also two different modes - native and compatibility. Native mode files would not necessarily be able to interpreted on a different machine than they were created on. As such, there aren't many examples of native mode files available.
 == Identification ==
-At least some TERSE-compressed files start with bytes {{magic|05 01 01 00}}.
+TERSE files use either a 4 or 12 byte header, depending on if it is using native or compatibility mode. Native mode have a header of either {{magic|01 89 69 A5}} or {{magic|07 89 69 A5}}, apparently depending on which version they were created with. Compatibility mode headers start with {{magic|02 00}} or {{magic|02 01}} for PACK and {{magic|05 00}} or {{magic|05 01}} for SPACK. In both cases, the second byte being 1 indicates [https://www.ibm.com/docs/en/zos/2.1.0?topic=options-record-format-recfm RECFM=V]. It is assumed the alternative is RECFM=U, but this is uncertain.
 == Related formats ==
@@ Line 20: / Line 22: @@
 So, apparently, [[PKWARE DCL Implode]] is closely related to TERSE. It's possible that this distinction is or is related to the PACK/SPACK distinction in the file type.
 == Software ==
@@ Line 27: / Line 31: @@
 ** [https://www.ibm.com/support/knowledgecenter/SSB27H_6.2.0/fa2ut_part3_terse.html IBM Knowledge Center: Terse Utility]
 * [https://github.com/openmainframeproject/tersedecompress TerseDecompress] – open source (Apache2 licensed) Java program, written by IBM, to decompress TERSE files for mainframe.
 == Links ==