What is area512?

AREA512 is a tiny operating system built for a small handheld device called the Cardputer ADV, which has only 512 kilobytes of memory and 8 megabytes of storage. It is built on top of another project called FemtoRuby, which means you can write programs in the Ruby language directly on the device itself, then compile and run them on the spot. Once installed with a tool called esptool, the device shows a file manager on its small screen. You move around with keys similar to vim style navigation, and you can open folders, run programs, edit files with a built in text editor, compile Ruby scripts into a faster bytecode format, create or delete files and folders, and reboot the device, all from the keyboard. A microSD card, formatted as FAT32, stores your files and app data. The system comes with several small preinstalled applications: a word processor called Writer, a schedule manager called Scheduler, a simple spreadsheet called Calc, a drawing program called Paint, and two games, a card game called Solitair and a game called Bomb. Each application has its own README explaining how to use it. For people who want to write their own applications, an app is just a folder containing compiled Ruby bytecode files and an optional manifest file listing which files to load and in what order. Programs run inside a sandbox on the device. Building AREA512 from source requires specific tools: version 5.5 or later of Espressif's ESP-IDF development framework, Ruby with its Bundler package manager, the physical Cardputer ADV hardware, and a USB-C cable to flash it. The project welcomes contributions of new built in applications and artwork. This project is aimed at hobbyists interested in small embedded devices and Ruby programming, not general computer users, since it requires specific hardware to run at all. It is released under the MIT license.