ColoRIX

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|subcat=Graphics
 
|subcat=Graphics
 
|extensions={{ext|sc?}}, {{ext|scf}}, {{ext|sci}}, {{ext|scr}}, {{ext|scx}}, {{ext|rix}}, {{ext|vmg}}, others
 
|extensions={{ext|sc?}}, {{ext|scf}}, {{ext|sci}}, {{ext|scr}}, {{ext|scx}}, {{ext|rix}}, {{ext|vmg}}, others
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|released=≤1986
 
}}
 
}}
'''ColoRIX''', or '''RIX''', is a raster image file format associated with the ''ColoRIX VGA Paint'' and ''EGA Paint'' applications for MS-DOS, developed by RIX SoftWorks. There are at least two versions of it. Images may be compressed or uncompressed.
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'''ColoRIX''', or '''RIX''', is a raster image file format associated with the ''EGA Paint'' and ''ColoRIX VGA Paint'' applications for MS-DOS, developed by RIX SoftWorks. There are at least two versions of it.
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== Format details ==
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The "new" format (with "RIX3" signature) has a 10-byte header, then an optional and rare "extension block", then a color palette, then the image data. If the image is compressed, the high bit of the byte at offset 9 is set.
 +
 
 +
The "old" format lacks the header. If the image is compressed, the high bit of the first byte of the file is set. The low 6 bits of the first 16 bytes are an EGA-style color palette. The image data starts at offset 16.
 +
 
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Both old and new ColoRIX files may optionally be compressed, using a fairly complex compression scheme. The compression scheme starts by splitting the image data into one or more segments. For 256-color images only, an [[Exclusive Or|XOR]] filter is applied. Then comes [[run-length encoding]], followed by [[Huffman coding]]. It is vaguely similar to [[Squeeze]], though the details are different.
  
 
== Identifiers ==
 
== Identifiers ==
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== Identification ==
 
== Identification ==
The VGA Paint version of the format begins with ASCII characters "{{magic|RIX3}}".
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New (VGA Paint) format: Files begin with ASCII characters "{{magic|RIX3}}".
  
 
Note that the VGA Paint distribution includes other files, in other formats, that also begin with "{{magic|RIX}}", but have a different fourth byte.
 
Note that the VGA Paint distribution includes other files, in other formats, that also begin with "{{magic|RIX}}", but have a different fourth byte.
  
''[TODO: Other versions]''
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Uncompressed old format: There's no robust way to identify the format, though you could check the file size (exactly 112016 bytes for SCR format), and validate the palette.
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 +
Compressed old format: There's no easy way to identify the format, though it is possible to identify it by reading the file and checking for errors.
  
 
== Specifications ==
 
== Specifications ==
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== Software ==
 
== Software ==
 
* [https://archive.org/details/colorix-vga-paint-1.36 ColoRIX VGA Paint 1.36] (at Internet Archive)
 
* [https://archive.org/details/colorix-vga-paint-1.36 ColoRIX VGA Paint 1.36] (at Internet Archive)
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* [http://old-dos.ru/index.php?page=files&mode=files&do=show&id=6763 ColoRIX VGA Paint] - Various versions at old-dos.ru
 
* RIXLATE.EXE - Format conversion utility for DOS, included with, e.g., ColoRIX VGA Paint 1.36
 
* RIXLATE.EXE - Format conversion utility for DOS, included with, e.g., ColoRIX VGA Paint 1.36
 
* [[Konvertor]]
 
* [[Konvertor]]
 
* [[XnView]]
 
* [[XnView]]
 
* [http://pulkomandy.tk/projects/GrafX2 GrafX2]
 
* [http://pulkomandy.tk/projects/GrafX2 GrafX2]
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* {{Deark}}
  
 
== Sample files ==
 
== Sample files ==
 
* {{CdTextfiles|carousel344/015/VGARIX.ZIP|VGARIX.ZIP}} → *.SCI
 
* {{CdTextfiles|carousel344/015/VGARIX.ZIP|VGARIX.ZIP}} → *.SCI
* https://telparia.com/fileFormatSamples/image/rix/
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* {{DexvertSamples|image/rix}}
 
* [https://archive.org/details/disc-passage-countriesofthe-world-1991 SCF Samples]
 
* [https://archive.org/details/disc-passage-countriesofthe-world-1991 SCF Samples]
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* [https://archive.org/details/SDN1__793 SDN¹ Plus] → demos/colorix.zip → *.SCF
 
* [https://archive.org/details/shareware-grab-bag Shareware Grab Bag] → 008/egaslide.arc - EGA Slide, a component of EGA Paint (?). Includes some .SCR files in an old version of the format.
 
* [https://archive.org/details/shareware-grab-bag Shareware Grab Bag] → 008/egaslide.arc - EGA Slide, a component of EGA Paint (?). Includes some .SCR files in an old version of the format.
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=== The Rolex demo ===
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Apparently, RIX SoftWorks released a "Rolex" clock demo app that loads and displays an included (old-format) RIX file.
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* [https://archive.org/details/msdos_festival_ROLEX MS-DOS Shareware: ROLEX]
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* {{CdTextfiles|swextrav1993/disk1/grprogs/rolex.zip|rolex.zip}}
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And some people modified it to display a custom image. A few of these mods may be found by searching the [https://archive.org/details/software Internet Archive Software Collection] for "rix softworks" (some may be NSFW).
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* Other examples (compressed): {{CdTextfiles|swextrav1993/disk1/grprogs/micky.zip|micky.zip}}, {{CdTextfiles|swextrav1993/disk1/files/ega/tiggs.zip|tiggs.zip}}, {{CdTextfiles|powerpakgold/GRAPHICS/GARFY.ZIP|GARFY.ZIP}}, {{CdTextfiles|powerpakgold/GRAPHICS/SMURF.ZIP|SMURF.ZIP}}, {{CdTextfiles|powerpakgold/GRAPHICS/MEGCLOCK.ZIP|MEGCLOCK.ZIP}}
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* Other examples (uncompressed): {{CdTextfiles|swextrav1993/disk1/files/gamesb/buny.zip|buny.zip}}, {{CdTextfiles|swextrav1993/disk1/files/ega/pinkp.zip|pinkp.zip}}, {{CdTextfiles|powerpakgold/GRAPHICS/TWEET.ZIP|TWEET.ZIP}}, {{CdTextfiles|powerpakgold/GRAPHICS/USA_1.ZIP|USA_1.ZIP}}, {{CdTextfiles|powerpakgold/GRAPHICS/EMIKO1.ZIP|EMIKO1.ZIP}}
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== Links ==
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* [https://books.google.com/books?id=Y01EX9nPrTwC&lpg=PA3&pg=PA287#v=onepage&q&f=false EGA Paint ad in PC Magazine, Mar 10, 1987, p. 287]
  
 
[[Category:File formats with too many extensions]]
 
[[Category:File formats with too many extensions]]

Latest revision as of 04:21, 28 December 2023

File Format
Name ColoRIX
Ontology
Extension(s) .sc?, .scf, .sci, .scr, .scx, .rix, .vmg, others
Released ≤1986

ColoRIX, or RIX, is a raster image file format associated with the EGA Paint and ColoRIX VGA Paint applications for MS-DOS, developed by RIX SoftWorks. There are at least two versions of it.

Contents

[edit] Format details

The "new" format (with "RIX3" signature) has a 10-byte header, then an optional and rare "extension block", then a color palette, then the image data. If the image is compressed, the high bit of the byte at offset 9 is set.

The "old" format lacks the header. If the image is compressed, the high bit of the first byte of the file is set. The low 6 bits of the first 16 bytes are an EGA-style color palette. The image data starts at offset 16.

Both old and new ColoRIX files may optionally be compressed, using a fairly complex compression scheme. The compression scheme starts by splitting the image data into one or more segments. For 256-color images only, an XOR filter is applied. Then comes run-length encoding, followed by Huffman coding. It is vaguely similar to Squeeze, though the details are different.

[edit] Identifiers

Many filename extensions have been reported or observed. Most are listed below. Extensions beginning with "SC" are generally used for full-screen images, with the third letter a code for the screen mode.

Ext. Mode Remarks
.RIX  ? Used generically?
.SCA  ?
.SCB  ?
.SCC  ?
.SCD 320x200x16
.SCE 640x200x16
.SCF 640x480x256
.SCG 800x600x16
.SCI 320x200x256
.SCK 320x400x256
.SCL 640x400x256
.SCN 800x600x256
.SCO 1024x768x256
.SCP 640x480x16
.SCQ 360x480x256
.SCR 640x350x16
.SCT 640x400x16
.SCU 1024x768x16
.SCV  ?
.SCW 640x350x256
.SCX  ? Seems to be used for various image sizes.
.SCY  ?
.SCZ Text mode?
.VMG Various Default extension for non-fullscreen images saved by VGA Paint

[edit] Identification

New (VGA Paint) format: Files begin with ASCII characters "RIX3".

Note that the VGA Paint distribution includes other files, in other formats, that also begin with "RIX", but have a different fourth byte.

Uncompressed old format: There's no robust way to identify the format, though you could check the file size (exactly 112016 bytes for SCR format), and validate the palette.

Compressed old format: There's no easy way to identify the format, though it is possible to identify it by reading the file and checking for errors.

[edit] Specifications

[edit] Software

[edit] Sample files

[edit] The Rolex demo

Apparently, RIX SoftWorks released a "Rolex" clock demo app that loads and displays an included (old-format) RIX file.

And some people modified it to display a custom image. A few of these mods may be found by searching the Internet Archive Software Collection for "rix softworks" (some may be NSFW).

[edit] Links

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