Spark - Revision history

Jsummers: /* Sample files */ Re-updated samples link

2025-08-01T17:53:13Z

‎Sample files: Re-updated samples link

2025-08-01T17:52:37Z

Undo revision 46587 by Dexvertbot (talk)

2023-12-28T02:55:29Z

Change telparia.com samples link to template

2023-10-17T23:24:36Z

‎Sample files

2023-03-26T15:27:45Z

2022-10-04T12:24:03Z

2022-01-19T18:01:33Z

2021-05-31T15:23:25Z

2021-02-16T21:32:10Z

‎Format details

2020-02-10T20:47:49Z

‎Format details

@@ Line 45: / Line 45: @@
 * Many of the files at [http://www.arcade-bbs.net/filepages/findex.htm The Arcade BBS Filebase] ([ftp://www.arcade-bbs.net/ ftp])
 ** E.g. [http://www.arcade-bbs.net/filepages/file77.htm Sprite Picture files] → {{ArcadeBBSLink|028864|level1}}
-* https://telparia.com/fileFormatSamples/archive/acornSpark/
+* {{DexvertSamples|archive/acornSpark}}
 [[Category:RISC OS]]

@@ Line 36: / Line 36: @@
 * [https://armclub.org.uk/products/arcfs/ ArcFS]
 * [https://github.com/mjwoodcock/nspark nspark] - a tool to catalogue and unpack Spark archives (in source code form)
-* [http://www.svgalib.org/rus/nomarch.html nomarch] v1.3  can unpack Spark archives.
+* [http://www.svgalib.org/rus/nomarch.html nomarch] v1.3+ can unpack Spark archives.
 * [https://github.com/mjwoodcock/riscosarc/ RISC OS de-archiver]
 * [https://www.davidpilling.com/riscos.html], [https://www.davidpilling.com/free.html] → Spark, SparkPlug
@@ Line 45: / Line 45: @@
 * Many of the files at [http://www.arcade-bbs.net/filepages/findex.htm The Arcade BBS Filebase] ([ftp://www.arcade-bbs.net/ ftp])
 ** E.g. [http://www.arcade-bbs.net/filepages/file77.htm Sprite Picture files] → {{ArcadeBBSLink|028864|level1}}
-* {{DexvertSamples|archive/acornSpark}}
+* https://telparia.com/fileFormatSamples/archive/acornSpark/
 [[Category:RISC OS]]

@@ Line 36: / Line 36: @@
 * [https://armclub.org.uk/products/arcfs/ ArcFS]
 * [https://github.com/mjwoodcock/nspark nspark] - a tool to catalogue and unpack Spark archives (in source code form)
-* [http://www.svgalib.org/rus/nomarch.html nomarch] v1.3+ can unpack Spark archives.
+* [http://www.svgalib.org/rus/nomarch.html nomarch] v1.3  can unpack Spark archives.
 * [https://github.com/mjwoodcock/riscosarc/ RISC OS de-archiver]
 * [https://www.davidpilling.com/riscos.html], [https://www.davidpilling.com/free.html] → Spark, SparkPlug
@@ Line 45: / Line 45: @@
 * Many of the files at [http://www.arcade-bbs.net/filepages/findex.htm The Arcade BBS Filebase] ([ftp://www.arcade-bbs.net/ ftp])
 ** E.g. [http://www.arcade-bbs.net/filepages/file77.htm Sprite Picture files] → {{ArcadeBBSLink|028864|level1}}
-* https://telparia.com/fileFormatSamples/archive/acornSpark/
+* {{DexvertSamples|archive/acornSpark}}
 [[Category:RISC OS]]

@@ Line 45: / Line 45: @@
 * Many of the files at [http://www.arcade-bbs.net/filepages/findex.htm The Arcade BBS Filebase] ([ftp://www.arcade-bbs.net/ ftp])
 ** E.g. [http://www.arcade-bbs.net/filepages/file77.htm Sprite Picture files] → {{ArcadeBBSLink|028864|level1}}
 [[Category:RISC OS]]

@@ Line 33: / Line 33: @@
 == Software ==
 * [https://github.com/mjwoodcock/nspark nspark] - a tool to catalogue and unpack Spark archives (in source code form)
 * [http://www.svgalib.org/rus/nomarch.html nomarch] v1.3+ can unpack Spark archives.

@@ Line 38: / Line 38: @@
 * [https://www.davidpilling.com/riscos.html], [https://www.davidpilling.com/free.html] → Spark, SparkPlug
 * {{Deark}}
 == Sample files ==

@@ Line 9: / Line 9: @@
 The format is an incompatible variant of [[ARC (compression format)|ARC]]. The most obvious differences from ARC are that the high bit of the ''compression method'' byte is set, and the member file header has an additional 12 bytes, for RISC OS file attributes. Subdirectories are possible, in a way, by storing them as nested Spark archives.
-Spark uses a subset of [[ARC (compression format)|ARC]]'s compression methods, with the same numbering scheme (taking the compression method to be the low 7 bits of the compression byte). It adds one method of its own:
+=== Compression methods ===
 {| class="wikitable"
-! ID !! Name !! Description and remarks
+! ID (8-bit) !! ID (7-bit) !! Name !! Description and remarks
 |-
-|127 || Compress || [[LZW]]. Like ARC's method #8, but does not use RLE, and has a configurable maximum code size up to 16 bits.
+|<code>0xff</code> || 127 || Compressed || [[LZW]]. Like method #8, but does not use RLE, and has a configurable maximum code size up to 16 bits.
 |}