azw413/ternos

TernOS is custom software that turns a small, pocket-sized e-ink screen into a genuinely useful everyday device. Instead of being locked into a single app, it gives the hardware a home screen, a file browser, an eBook reader, and an image viewer. Its two main goals are letting you read books on the low-power e-ink screen and acting as a wallet to carry around loyalty cards, tickets, and boarding passes. Because e-ink displays are persistent, the screen keeps showing your boarding pass even if the device completely loses power. The software is designed for devices like the XTEink X4, a small reader with physical buttons and no touchscreen. To make content work on this limited hardware, you first convert your files on a regular computer using the project's web app or desktop tools. Images and EPUB books are processed into compact, pre-formatted files that the small device can easily handle. For things like QR codes on boarding passes, the conversion tool can even detect the barcode and re-render it so scanners can read it reliably. Once your files are on the device's SD card, you navigate using the physical buttons to browse your library and open books or images. The reader includes standard features like a table of contents, embedded images, and a resume function that remembers where you left off. The device also has a power-saving sleep mode that kicks in after five minutes of inactivity, leaving your current page or pass on the screen. Beyond just reading, the project is notable because it acts as a general-purpose operating system inspired by the classic PalmOS. It actually emulates the old Palm hardware, meaning it can run decades-old Palm apps. The project is written in Rust and is still actively being developed, with ongoing work to expand its library and finish the native app system. For non-developers, the easiest way to get started is using the web app to flash the firmware and convert files.