Freedom251 › Commodore 64 Emulators
Viciious
What Viciious is
Viciious is a free JavaScript emulator of a PAL Commodore 64 that runs in web browsers or as a Node.js bundle in a terminal. It is intended for exploring C64 hardware and software. The emulator recreates the VIC-II graphics chip at 320×200 resolution in 16 colors and the SID synthesizer with three simultaneous voices, each spanning nine octaves. A BASIC environment and half-assembler support experimentation with 6502 opcodes in inline JavaScript. In a browser, users can drag in .t64, .d64, .tap, .prg, and .sid files. Real-time scopes show machine activity, including sprite pixels and device access to RAM. Its distribution is a self-contained HTML file that runs serverless without accessing the Internet; a Node.js bundle can also run in a terminal. Viciious is not cycle-accurate, has no disk-drive emulation, and lacks some features such as sound filtering. The project says compatibility is incomplete because of emulation limits and bugs. The interface is unsuitable for mobile use, even though the emulator can run there in real time. The code and UI assets are public domain, with exceptions noted for bundled ROMs, tests, and demo programs.
Who it suits
Viciious suits people interested in tinkering with and exploring Commodore 64 hardware or software. It offers browser and terminal use, but its interface is described as unsuitable for mobile devices.
What it does well
- Runs as a self-contained browser HTML file.
- Includes BASIC and a half-assembler.
- Real-time scopes visualize machine activity.
- Accepts five browser file formats by drag and drop.
What to know first
- Emulation is not cycle-accurate.
- It does not emulate a disk drive.
- Compatibility is incomplete due to limitations and bugs.
- The interface is unsuitable for mobile use.
Limits
Viciious is a PAL Commodore 64 emulator, but it is not cycle-accurate, does not emulate a disk drive, and lacks some features such as sound filtering. Compatibility is incomplete, and the mobile interface is unsuitable even though the emulator can run there in real time.
Getting started
- Open https://luxocrates.github.io/viciious/ in a web browser.
- Alternatively, build the Node.js bundle to use it with a terminal emulator.
- Drag a supported .t64, .d64, .tap, .prg, or .sid file into the browser window to load it.
- Explore the BASIC environment, half-assembler, and real-time scopes.
Verdict
Viciious provides several tools for exploring a PAL Commodore 64 in a browser or terminal. It is not a complete emulator, and its compatibility and mobile interface have stated limits.
Questions
Is Viciious free?
Yes. It is listed as free, with a free plan and no free trial.
Which platforms does it support?
It runs in web browsers and can be built as a Node.js bundle for a terminal emulator.
What file formats can I load?
The browser version accepts .t64, .d64, .tap, .prg, and .sid files by drag and drop. The listed disk and tape formats also include .json snapshots.
Is Viciious open source?
The emulator code and UI assets were authored from scratch and placed in the public domain. The repository notes exceptions for bundled ROMs, tests, and demo programs.
Which Commodore 64 variant does it emulate?
Viciious emulates a PAL Commodore 64.
Can it be used on mobile?
It can run in real time on mobile, but its interface is described as unsuitable there.
Facts from Viciious's own pages
- Audio
- Its SID emulation provides three simultaneous voices, each with a nine-octave range. · github.com, 3 Oct 2026
- Compatibility
- The project says compatibility is incomplete due to emulation limitations and bugs. · github.com, 3 Oct 2026
- Distribution
- The emulator is distributed as a self-contained HTML file that does not access the Internet and runs serverless. · github.com, 3 Oct 2026
- Emulation limits
- It emulates a PAL Commodore 64 in real time but is not cycle-accurate, does not emulate a disk drive and lacks some features such as sound filtering. · github.com, 3 Oct 2026
- Exploration tools
- Real-time scopes visualize machine activity, including sprite-generated pixels and devices accessing RAM. · github.com, 3 Oct 2026
- File formats
- The browser version accepts .t64, .d64, .tap, .prg and .sid files by drag and drop. · github.com, 3 Oct 2026
- File loading
- In the browser, users can drag and drop .t64, .d64, .tap, .prg, and .sid files into the window. · github.com, 2 Oct 2026
- Graphics
- Its VIC-II emulation supports 320×200 graphics in 16 colors. · github.com, 3 Oct 2026
- Intended users
- The project says it was written for tinkering and playful exploration of Commodore 64 hardware and software. · github.com, 3 Oct 2026
- License
- The emulation code and UI assets were authored from scratch and placed in the public domain, with stated exceptions for bundled ROMs, tests and demo programs. · github.com, 3 Oct 2026
- Mobile
- It can run in real time on mobile, but the user interface is unsuitable there. · github.com, 3 Oct 2026
- Node.js
- The emulator can be built as a Node.js bundle and run with a regular terminal emulator for input and output. · github.com, 2 Oct 2026
- Product
- Viciious is a JavaScript emulator of the Commodore 64 for web browsers and terminal emulators. · github.com, 3 Oct 2026
- Programming
- It includes a BASIC programming environment and a half-assembler for writing 6502 opcodes as inline JavaScript. · github.com, 3 Oct 2026
- Purpose
- The project says it was written for tinkering and playful exploration of Commodore 64 hardware and software. · github.com, 2 Oct 2026
- Visual tools
- It offers real-time scopes that visualize machine activity, including sprite-generated pixels and device access to RAM. · github.com, 2 Oct 2026
Where Viciious stands on Freedom251
- Commodore 64 Emulators#23 of 31