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Rust64

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What Rust64 is

Rust64 is a free Commodore 64 emulator written in Rust. The project is intended to explain how the C64 works and what happens as a program starts. It uses cycle-based emulation, described by its author as fairly accurate, and includes a visual debugger. The debugger can display RAM pages, Color RAM, VIC registers, CIA registers, and SID registers; its raster view maps each pixel to a VIC cycle and the events at that time. A .prg file can be loaded into memory at startup through a command-line argument, and the listed formats are PRG and CRT. Building and running require Rust 1.58.0 or later, with minifb and SDL2 among the major dependencies; SDL2 needs extra setup. Missing serial-bus support can make programs malfunction or enter infinite loops, while precise-timing software may fail. The project is an on-and-off work in progress, has no GitHub releases, and uses an MIT license.

Who it suits

Rust64 suits developers, emulator learners, and Commodore 64 users who want source code and a built-in debugger. It is also useful for examining C64 operation rather than relying on a packaged release.

What it does well

  • Free and open under the MIT license
  • Includes a visual hardware debugger
  • Supports PRG and CRT formats
  • Loads PRG files at startup
  • Shows VIC cycle raster events

What to know first

  • Requires Rust 1.58.0 or later
  • SDL2 needs extra setup
  • Missing serial bus affects some programs
  • No GitHub releases are available

Verdict

Rust64 offers a code-focused C64 emulator with detailed register and cycle views. Its missing serial bus, timing limitations, build requirements, and work-in-progress status should guide expectations.

Facts from Rust64's own pages

Availability
The GitHub releases page says there are no releases. · github.com, 9 Oct 2026
Build
The README gives Cargo build and run commands and says Rust 1.58.0 or later is required. · github.com, 9 Oct 2026
Build requirement
Building and running Rust64 requires Rust 1.58.0 or higher. · github.com, 9 Oct 2026
Debugger
Its built-in visual debugger can display RAM pages, Color RAM, VIC registers, CIA registers, and SID registers. · github.com, 9 Oct 2026
Dependencies
The README lists minifb and SDL2 as major dependencies and says SDL2 requires extra setup. · github.com, 9 Oct 2026
Distribution
The GitHub releases page says there are no releases. · github.com, 9 Oct 2026
Emulation
The emulator uses cycle-based emulation that the author describes as fairly accurate. · github.com, 9 Oct 2026
Known limitation
The README says the missing serial bus may cause some programs to behave incorrectly or get stuck in infinite loops. · github.com, 9 Oct 2026
Known limitations
The maker says the missing serial bus can cause some programs to malfunction or get stuck, and programs needing very precise timing may not work correctly. · github.com, 9 Oct 2026
License
The repository displays an MIT license. · github.com, 9 Oct 2026
Loading programs
A .prg file can be passed as a command-line argument to load it into memory when the emulator starts. · github.com, 9 Oct 2026
Load programs
A .prg file can be passed as a command-line parameter to load it into memory at startup. · github.com, 9 Oct 2026
Maintenance
The README describes the project as an on-off work in progress whose update frequency may vary. · github.com, 9 Oct 2026
Maker
The GitHub profile identifies the maker as Krzysztof Kondrak and lists Poland as the location. · github.com, 9 Oct 2026
Planned work
The TODO list includes serial bus and disk drive support for D64, T64, and TAP formats, remaining undocumented operations, and improving SID emulation. · github.com, 9 Oct 2026
Product
Rust64 is a Commodore 64 emulator written in Rust. · github.com, 9 Oct 2026
Purpose
The project aims to explain how the Commodore 64 works and what happens behind the scenes when a program starts. · github.com, 9 Oct 2026
Raster view
The VIC debugger represents each pixel as a VIC cycle and the events occurring at that time. · github.com, 9 Oct 2026

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