cardinal-varvara

Cardinal is a fork of Raven an independent re-implementation of the Uxn CPU and Varvara Ordinator.

The Uxn/Varvara ecosystem is a personal computing stack.

Cardinal is my personal stack for the Uxn/Varvara ecosystem.

For details on project origins, see Raven's project writeup.

The cardinal-uxn crate includes two implementations of the Uxn CPU:

• The safe interpreter is a #[no_std] crate written in 100% safe Rust, with a single dependency (zerocopy). It is 10-20% faster than the reference implementation for CPU-heavy workloads (e.g. fib.tal, and mandelbrot.tal
• The unsafe ("native") interpreter is written in aarch64 assembly (with Rust shims on either side), and runs 40-50% faster than the reference implementation

The native interpreter can be checked against the safe interpreter with fuzz testing:

cargo install cargo-fuzz # this only needs to be run once
cargo +nightly fuzz run --release fuzz-native

The Varvara implementation (cardinal-varvara) includes all peripherals, and has been tested on many of the flagship applications (Left, Orca, Noodle, Potato).

The repository includes two applications built on these libraries:

• cardinal-cli is a command-line application to run console-based ROMs
• cardinal-gui is a full-fledged GUI, which runs both as a native application and Raven on the web

The web demo is built with truck, e.g.

cargo install --locked trunk # this only needs to be run once
cd cardinal-gui
trunk build --release --public-url=/projects/cardinal/demo/ # edit this path

technology from the past come to save the future from itself

July 2025 Changes

• stdout and stderr callbacks
• feat(audio): support dynamic sample rate selection between 48000 and 44100 Hz
• refactor(deps): update to the latest and greatest 7/25 for all dependencies!
• feat(cardinal-gui): add cardinal-demo binary with hot reload, inject, and rom cycling; cardinal-orcas binary added, wip.
• wasm notice: cardinal-gui supports wasm. the others do not. PRs welcome.
• /notes/01.debug basic debug start.
• /notes/02.duplicate_mouse_device demonstrate custom Tracker Mouse device.
• resolved 100+ clippy lints. wasm, ubuntu, windows, and macos all show green.
• /notes/03.hidusb_controllers
• /notes/04.sym_file_vector_labeling
• /notes/05.cardinal-orcas
• /notes/06.hardware_verification
• /notes/07.xbox_controller_gilrs
• /notes/08.e_midi

© 2024-2025 Matthew Keeter, David Horner Released under the Mozilla Public License 2.0

The repository includes ROMs compiled from the uxnemu reference implementation, which are © Devine Lu Linvega and released under the MIT license; see the roms/ subfolder for details.

we do not know what exactly will come of it