TRX64
github.com
What it is
TRX64 is a free, open-source Rust runtime for cycle-accurate emulation of the Commodore 64, 1541, and 1581. Its reverse-engineering tools include rewind, byte-exact reverse stepping, write tracking, observers, traces, marks, and sandboxes. A daemon exposes JSON-RPC 2.0 over WebSocket, with project capabilities available through JSON-RPC methods. Users can work with trx64cli, a terminal cockpit with an optional native emulator window, or C64RE, a browser-based reverse-engineering workbench. The daemon supports c64, u64, and 128 machine selections, with PAL and NTSC C64 models documented. Media and hardware support includes D64/G64 disks in 1541 drives, D81 disks in 1581 drives, cartridge types, REU, GeoRAM, and the Ultimate Command Interface. It also supports machine snapshots, reverse-debug buffers, trace logs, and VICE .vsf snapshot conversion. Releases are available for Linux, macOS, and Windows, with builds for x86_64 and arm64 where listed. C64 ROMs, including the 1581 DOS ROM, are not included and must be supplied separately.
Spec sheet
- What it does
- TRX64 is a Rust runtime for cycle-accurate Commodore 64, 1541 and 1581 emulation.Read 15 Oct 2026 · github.com
- Purpose
- TRX64 is a cycle-accurate Commodore 64, 1541, and 1581 emulation runtime written in Rust.Read 9 Oct 2026 · github.com
- API
- The public control interface is JSON-RPC 2.0 over WebSocket.Read 15 Oct 2026 · github.com
- Integrations
- TRX64 is described as the runtime backend for C64RE and the C64U / UE2 Emulator, and it offers a typed UniFFI library with Swift bindings.Read 9 Oct 2026 · github.com
- Support
- The maker directs users to GitHub issues and says they cannot provide real support.Read 15 Oct 2026 · github.com
- License
- The project is licensed under GPL-3.0-or-later.Read 9 Oct 2026 · github.com
- Architecture
- The project provides a daemon and JSON-RPC API with multiple front ends sharing one emulated machine per process.Read 15 Oct 2026 · github.com
- Cartridges
- Supported cartridge formats include generic 8K/16K/Ultimax, Ocean, Magic Desk, EasyFlash, GMod2, GMod4, MegaByter and C64MegaCart.Read 15 Oct 2026 · github.com
- Checkpoints
- Full-machine checkpoints support scrubbing and read-only diffs between saved points.Read 15 Oct 2026 · github.com
- CLI cockpit
- trx64cli combines a terminal cockpit with an optional native emulator window.Read 15 Oct 2026 · github.com
- Debugging
- It provides rewind, byte-exact reverse stepping, write tracking, observers, traces, marks, and sandboxes for reverse engineering.Read 9 Oct 2026 · github.com
- Disk formats
- The emulator supports D64 and G64 images in 1541 drives and D81 images in 1581 drives.Read 15 Oct 2026 · github.com
- Documentation
- The repository includes a README, a 228-line monitor reference and a separate CLI README.Read 15 Oct 2026 · github.com
- Downloads
- The releases page provides prebuilt assets for Linux, macOS, and Windows, including x86_64 and arm64 builds where listed.Read 9 Oct 2026 · github.com
- Expansion hardware
- REU, GeoRAM and Ultimate Command Interface devices are supported.Read 15 Oct 2026 · github.com
- Extensibility
- Hosts can attach custom IEC devices and disk controllers through documented Rust interfaces.Read 15 Oct 2026 · github.com
- Headless operation
- The daemon can run headlessly and advances only when explicitly commanded.Read 15 Oct 2026 · github.com
- Independent report: automation
- The announcement says TRX64 can run in Docker for automated testing or locally from the command line.Read 15 Oct 2026 · lemon64.com
- Independent report: implementation
- A Lemon64 announcement describes TRX64 as a Rust runtime intended to be broadly comparable with VICE.Read 15 Oct 2026 · lemon64.com
- Independent report: input limitation
- The maker stated in the forum announcement that only keyboard and keyboard-as-joystick input were implemented, with no operating-system joystick or mouse support planned.Read 15 Oct 2026 · lemon64.com
- Independent report: media
- The same announcement lists D64, G64 and CRT support and describes the 1541 as a true-drive emulation.Read 15 Oct 2026 · lemon64.com
- Independent report: reverse buffer
- The announcement describes a default ten-second ring buffer for stepping backward and rerunning code.Read 15 Oct 2026 · lemon64.com
- Install options
- The README documents installation through Homebrew and building from source with cargo build --release.Read 9 Oct 2026 · github.com
- Installation
- Prebuilt archives target macOS, Linux and Windows on x86_64 and arm64; Homebrew and cargo source builds are also documented.Read 15 Oct 2026 · github.com
- Interfaces
- The project offers trx64cli, a terminal cockpit with an optional native emulator window, and C64RE, a browser-based reverse-engineering workbench.Read 9 Oct 2026 · github.com
- Licence
- The project is licensed under GPL-3.0-or-later and says its emulation cores derive from VICE under GPL-2.0-or-later.Read 15 Oct 2026 · github.com
- Limit: incomplete replacement
- The maker stated that TRX64 supports only a defined subset of C64 emulation and is not a full replacement for a real Ultimate 64.Read 15 Oct 2026 · lemon64.com
- Limit: missing device request
- The repository has an open feature request for an SD2IEC device with serial-bus timing and D64/D81 image support.Read 15 Oct 2026 · github.com
- Limit: rendering compatibility
- A Lemon64 tester reported that the Mandelbrot-upic demo did not render correctly under the emulator.Read 15 Oct 2026 · lemon64.com
- Machine modes
- The daemon offers c64, u64 and 128 machine selections plus PAL and NTSC C64 models.Read 15 Oct 2026 · github.com
- Maker and audience
- The maker describes TRX64 as a personal emulator developed for their own C64 game reverse-engineering needs and invites code contributions.Read 9 Oct 2026 · github.com
- Maker identity
- The GitHub account identifies the maker as Alex Damhuis and lists TRX64 among its public repositories.Read 15 Oct 2026 · github.com
- Media and hardware
- It supports D64/G64 disks in 1541 drives, D81 disks in 1581 drives, multiple cartridge types, REU, GeoRAM, and the Ultimate Command Interface.Read 9 Oct 2026 · github.com
- Observers
- Conditional observers can watch execution, reads or writes and trigger actions or tracing.Read 15 Oct 2026 · github.com
- Praise: emulator quality
- A later Lemon64 tester called the emulator impressive while reporting that some demos rendered correctly.Read 15 Oct 2026 · lemon64.com
- Praise: reverse debugging
- A Lemon64 participant said the first run already exposed useful commands and asked about running emulation backward.Read 15 Oct 2026 · lemon64.com
- Release news
- Release 0.13.1 was published on 15 October 2026 with drive trace records, sandbox RAM-write harvesting and an EPIPE daemon fix.Read 15 Oct 2026 · github.com
- Reverse debugging
- The runtime supports rewind, byte-exact reverse stepping and address write tracing.Read 15 Oct 2026 · github.com
- ROM requirement
- C64 ROMs are not included and must be supplied in ~/.trx64/roms or selected with --rom-dir; the 1581 DOS ROM is also not included.Read 9 Oct 2026 · github.com
- Rust embedding
- The trx64-core crate can be embedded by constructing a Machine and supplying ROMs.Read 15 Oct 2026 · github.com
- Snapshots
- TRX64 writes C64RE machine snapshots, reverse-debug ring files and trace logs, and converts VICE VSF snapshots.Read 15 Oct 2026 · github.com
- Snapshots and compatibility
- It supports .c64re machine snapshots, .c64rering reverse-debug buffers, .c64retrace trace logs, and conversion of VICE .vsf snapshots.Read 9 Oct 2026 · github.com
- Supported machines
- The daemon supports c64, u64, and 128 machine selections, with PAL and NTSC C64 models also documented.Read 9 Oct 2026 · github.com
- Swift integration
- The trx64-ffi crate exposes a typed UniFFI library with Swift bindings.Read 15 Oct 2026 · github.com
- System requirement
- Users must provide Commodore ROM files because releases do not bundle them.Read 15 Oct 2026 · github.com
- Tracing
- CPU, drive, IEC and memory events can be recorded to binary trace logs and queried with map, taint and swimlane analysis.Read 15 Oct 2026 · github.com
Plans and prices
Free and open source Free GPL-3.0-or-later · C64 ROMs are not included Read 9 Oct 2026 · github.com
TRX64 open-source software Free GPL-3.0-or-later · C64 ROMs not included Read 15 Oct 2026 · github.com
Strong points and limits
Strong points
- Free and open source under GPL-3.0-or-later.
- Provides byte-exact reverse stepping and write tracking.
- JSON-RPC 2.0 interface is available over WebSocket.
- Offers terminal and browser-based interfaces.
- Prebuilt releases cover Linux, macOS, and Windows.
Limits
- C64 ROMs must be supplied separately.
- The 1581 DOS ROM is not included.
- The maker says they cannot provide real support.
Who it suits
TRX64 suits Commodore 64 reverse-engineering work that benefits from cycle-accurate emulation and reverse-debugging tools. Its maker describes it as a personal emulator and invites code contributions.
Verdict
TRX64 combines Commodore emulation with detailed reverse-debugging tools and several interfaces. It requires separately supplied ROMs, and support is limited to GitHub issues rather than direct assistance.
Where Specifiction places it
- Commodore 64 Emulators#2 of 318.4