TCR to RGF Converter

Convert compressed text to RGF graphic — free online

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EV3-Ready Graphics

TCR to RGF conversion renders your PalmOS text as a monochrome image sized for the LEGO Mindstorms EV3 brick display.

Cloud Processing

The rendering and RGF encoding all happen on Convertio servers — no special software or LEGO development tools needed on your end.

Works in Any Browser

Access TCR to RGF conversion from Chrome, Firefox, Safari, or Edge on any operating system — entirely browser-based.

How to convert TCR to RGF

1

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

2

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

3

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

About formats

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
RGF (Robot Graphics Format) is a simple monochrome bitmap image format used by LEGO Mindstorms EV3 programmable robotics kits, introduced with the EV3 system on September 1, 2013. RGF files store 1-bit (black and white) images designed for display on the EV3 Intelligent Brick's 178x128 pixel monochrome LCD screen. The format uses a minimal structure: a header containing the image width and height as binary values, followed by the pixel data where each bit represents one pixel (1 for black, 0 for white), packed eight per byte in row-major order. RGF images are used as custom display graphics in EV3 programs — students and hobbyists create them for robot status displays, user interfaces, splash screens, and animation frames shown on the brick's screen during program execution. The images are typically designed using LEGO's EV3 software (which includes a built-in image editor) or converted from other formats using community tools. RGF fits within LEGO's broader educational robotics platform, where the Mindstorms system teaches programming, engineering, and computational thinking to students worldwide. One advantage is the format's role in educational technology: RGF provides a simple, concrete example of how digital images are represented as binary data — a concept that students working with Mindstorms can directly observe by examining the file contents and seeing the corresponding image on the brick's screen. The format's simplicity makes it accessible for young programmers learning about file formats and binary data. RGF files can be created and converted using ImageMagick, the EV3 development environment, and community tools like ev3dev.
Developer: The LEGO Group
Initial release: 2013

Frequently Asked Questions

Why convert TCR to RGF?

TCR is obsolete compressed text. RGF converts it into a monochrome graphic displayable on LEGO Mindstorms EV3 brick screens — a niche but fun use case.

What uses RGF files?

RGF images are designed for the LEGO Mindstorms EV3 intelligent brick display. The EV3 programming environment and related tools handle RGF natively.

How large is the EV3 display?

The EV3 brick screen is 178x128 pixels, monochrome. RGF images match these constraints for direct display on the robot controller.

Is the text readable in RGF?

Given the small EV3 screen size, only short text snippets render legibly. Longer TCR content may require truncation or small font rendering.

Can I convert TCR to RGF for free?

Yes, Convertio provides free TCR to RGF conversion. Premium plans offer batch uploads and higher file size thresholds.