SK to TCR Converter

Free SK to TCR conversion — Psion eBook format online

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Psion Compatibility

TCR is the native format for Psion handhelds. Convert SK files to TCR for compatibility with these classic PDA devices.

Online Conversion

No Psion software or Skencil installation required. Upload your SK file in any browser and receive TCR output.

Cloud Processing

Convertio servers handle the entire conversion remotely. Your local device does no processing work.

How to convert SK to TCR

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose tcr or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your tcr file right afterwards

About formats

SK is the native file format of Skencil (originally named Sketch), a free vector graphics editor for Linux created by Bernhard Herzog, with the first public release on October 31, 1998. Skencil holds historical significance as one of the earliest full-featured vector drawing applications written almost entirely in Python, with only performance-critical rendering components implemented in C. The SK file format uses a text-based, Python-like syntax to describe document structure — pages, layers, groups, and individual graphic objects are represented as nested statements with parameters specifying coordinates, colors, line styles, and transformations. The format supports Bezier curves, rectangles, ellipses, text objects with font specifications, imported raster images, gradient and pattern fills, and hierarchical grouping with affine transforms. One advantage is human readability — SK files can be opened in any text editor, making it possible to inspect, modify, or generate artwork programmatically using simple scripts. The Python-native structure also provides a benefit for automation: since Skencil itself is a Python application, the file format integrates naturally with scripting workflows for batch processing and procedural graphic generation. While Skencil's development slowed after the mid-2000s, its SK format became the foundation for the sK1) project, which extended the format and continued active open-source vector graphics development. SK files remain convertible through sK1, UniConvertor, and other open-source tools.
Developer: Bernhard Herzog
Initial release: October 31, 1998
TCR (Text Compression for Reader) is a compressed plain-text ebook format developed by Barry Childress in the early 1990s for the Psion Series 3 family of palmtop computers. The format was created for Childress's Reader3 application, a text file viewer that needed to fit large books into the Psion's extremely limited storage — typically 128 KB to 2 MB of available memory. TCR uses a dictionary-based compression scheme derived from the earlier ZVR format by Ian Giddings, replacing repeated byte sequences with single-byte tokens that reference a header dictionary. This straightforward approach achieves compression ratios of roughly 40-60% on typical English prose while requiring minimal CPU resources for decompression. The Psion Series 3 ran on a 3.84 MHz NEC V30 processor with no floating-point unit, so TCR's low computational overhead was essential for smooth page-by-page reading. A key advantage is remarkable storage efficiency for its simplicity — users could carry dozens of novels on removable SSD cards that held only a few hundred kilobytes. The format found a dedicated user community among Psion enthusiasts who built libraries of compressed literature for portable reading years before smartphones existed. Though the Psion platform faded from the market in the early 2000s, TCR files can still be opened and converted by modern ebook tools, and the format stands as an early example of purpose-built mobile reading technology from the pre-smartphone era.
Developer: Barry Childress
Initial release: 1993

Frequently Asked Questions

Why convert SK to TCR?

TCR is a compressed text format for Psion handhelds. Converting SK to TCR creates lightweight publications for those legacy devices.

What devices read TCR files?

Psion PDA devices and some eBook readers that support legacy formats can open TCR files. Calibre also handles TCR.

Is TCR still relevant?

TCR is a legacy format from the Psion era. It is useful only for compatibility with specific vintage handheld devices.

Does TCR support images?

TCR is primarily a text compression format. Visual content from SK files may be limited in the TCR output.

Is this conversion free?

Free SK to TCR conversion is available at Convertio. Premium plans offer higher limits for specialized workflows.