Emulators written in JavaScript

Frederic Cambus June 12, 2014 [JavaScript]

A list of emulators written in the JavaScript programming language.

This list started as a compilation of JavaScript emulators posted to Echo JS over the years. If you know about any missing emulators, please consider adding them to the collection: the source for this page is available on GitHub. Thank you in advance.

Acorn

Atom Tiny Emu - by Andre Weissflog (source)
Acorn Atom Emulator - by Phil Mainwaring. Software archive here. (Older version here: Type "OLD" for an Easter Egg.)
ElkJS - JavaScript based Acorn Electron emulator (Source)
JSBeeb - JavaScript BBC Micro emulator (Source) (Development blog)
JSAtom - JavaScript Acorn Atom emulator including Software Archive (Source) Based on JSBeeb

Altair

MITS Altair Simulator Front panel simulation of the 8080-based Altair, by Ian Davies, built on 8080.js

Amstrad

CPCBox - Amstrad CPC emulator in JavaScript (archive link)
CPC Tiny Emu - by Andre Weissflog (source)
Roland - An Amstrad CPC emulator written in JavaScript. (Source)

Apple

Apple 1js - by Will Scullin
Apple2e - Apple IIe emulator by John Clark (Source)
Apple IIjs - An Apple ][ Emulator in JavaScript
a2 - A fast, WebGL optimized Apple ][+ emulator
Apple2JS - A JavaScript emulator for the Apple II
BasiliskII - An Emscripten Port of BasiliskII (Demo 1, Demo 2)
MiniVMac-Em - An Emscripten Port of MiniVMac (Demo)
Yet Another Apple 2+ in JavaScript - by Thomas Skibo

Atari

8bit Workshop - VCS IDE by Steven Hugg, building on Javatari.js
EstyJS - A pretty fast and functional JavaScript Atari ST emulator (Source)
Javatari.js - Atari 2600 emulator by Paulo Augusto Peccin. (Example cartridges online) (Source)
jsA8E - JavaScript version of the A8E Atari 800 XL Emulator
JS7800 - JavaScript Atari 7800 Emulator

Commodore

Commodore LCD emulator - by Gábor Lénárt "LGB"
Commodore PET - by Thomas Skibo
JSC64 - Commodore 64 emulator written in JavaScript (Source)
c64js - Commodore 64 emulator written in JavaScript by Mikael Borgbrant (Source)
C64 Tiny Emu - by Andre Weissflog (source)
Kim1 - emulation in JavaScript by Rob Sayers (Source)
SAE - Scripted Amiga Emulator (Source)
VIC-20 Emulator - JavaScript VIC-20 emulator
VICE.js - Versatile Commodore Emulator for JavaScript (Source)

Data General

Novas Are Forever - by Wild Hare Computer Systems, for the 50th anniversary.

DEC

PDP-1 running the SpaceWar game and the Minskytron demo - by Norbert Landsteiner
PDP-8 and PDP-11 simulators with assembly language interfaces (explanatory articles with full source, not live site) - by programmer209
JavaScript PDP 11 - PDP-11/70 emulator with simulated front panel and a choice of operating systems. By Paul Nankervis
PDP-11 Emulator - A JavaScript PDP-11 emulator running UNIX Sixth Edition. By Julius Schmidt
- with teletype - PDP-11 emulator with teletype interface
pdp11-js - PDP-11 emulator with UNIX V6. By Takahiro Aoyagi (Source)

Nintendo

1964js - JavaScript port of the 1964 N64 emulator for Windows
CfxNES - JavaScript NES Emulator (Demo)
CycloaJS - JavaScript NES Emulator (Source)
em-fceux - an Emscripten port of FCEUX, an emulator of NES, Famicom, Famicom Disk System (FDS), and Dendy consoles. Demo site
GBA.js - Game Boy Advance in the Browser (Source)
IodineGBA - A GameBoy Advance emulator written entirely in JavaScript (Source)
gba.ninja - JavaScript port of VisualBoyAdvance-M, a GameBoy Advance emulator (Source)
JSNES - A JavaScript NES emulator (Source)
NESNES - JavaScript NES emulator, also available as a web component (Source)
Nezulator - A NES emulator in JavaScript
N64Wasm - A web based N64 Emulator (Source)
XNES - Experimental JavaScript Super Nintendo emulators (Source)
jsGB - A GameBoy emulator in JavaScript (Source)
jsGBC - GameBoy Color Emulator written in JavaScript (Source)
mupen64plus - A port of the popular Nintendo 64 emulator for the Web (Source)
n64js - An N64 emulator in JavaScript (Source)
pinky - A Rust based NES emulator ported to the web via WebAssembly (Source)
DeSmuME-wasm - A WebAssembly port of the DeSmuME Nintendo DS emulator (Demo)
Desmond.js - A portable/embeddable version of DeSmuME-wasm (Demo)
SkyEmu - SkyEmu is a low level GameBoy, GameBoy Color and Game Boy Advance emulator
CAMLBOY - A Game Boy emulator that runs in your browser written in OCaml

Robotron / VEB Mikroelektronik

KC85_Emu - KC85/3 and KC85/4 emulator by Alexander Lang
KC85/2 family emulators by Andre Weissflog (source):
LC-80 - single board U880-based trainer from the DDR (warning: auto-plays sound at boot), via emscripten. By Andre Weissflog (source)
Z1013 Tiny Emu - by Andre Weissflog (source)
KC87 Tiny Emu - by Andre Weissflog (source)

Sega

jsSMS - JavaScript Sega Master System & Game Gear emulator (Source)
Miracle - Sega Master System emulator (Source)

Sinclair

JSSpeccy - A ZX Spectrum emulator in JavaScript (Source)
JtyOne Online ZX81 Emulator - by Simon Holdsworth
Qaop/JS - ZX Spectrum emulator
ZX80 Emulator - JavaScript ZX80 Emulator
EMF ZX80 - EMF-based ZX80 Emulator - by Steven Goodwin (@MarquisdeGeek) (Source)
EMF ZX81 - EMF-based ZX81 Emulator - by Steven Goodwin (@MarquisdeGeek) (Source)
Science of Cambridge MK14 simulator - by Doug Rice, based on Paul Robson's offline emulator.
ZX Spectrum 48K Tiny Emy - by Andre Weissflog (source)
ZX Spectrum 128 Tiny Emu - by Andre Weissflog (source)

Sony

eNGE - JavaScript browser based PSX emulator (runs games at full speed) (Source)
PSeudo - JavaScript/WebGL/WebAudio browser based PLAYSTATION emulator (aka PSX) (needs boot ROM image, not supplied) (Source)
PCSXjs - Modified PCSX-Reloaded compiled with Emscripten (Source)
WASMpsx - Easily embeddable fork of PCSXjs
kpspemu - PSP Emulator written in Kotlin for JVM, JS and Native
Play!.js - This is a port of Play!, a PlayStation2 emulator, running in a web browser

Tandy

CloudT TRS-80 Model 100 Emulator - by John R. Hogerhuis (Announcement)
MC-10 Emulator - Emulator for the TRS-80 MC-10 microcomputer
TRS-80 Model III Emulator a JavaScript emulator for the TRS-80 Model III, by Peter Phillips
JS Mocha - The HTML5 CoCo 2 Emulator

Multi-system Emulators

JSMESS examples - The JavaScript MESS (Multi Emulator Super System) (Source) (Notes)
PCE - PC emulators in JavaScript (Atari ST, IBM PC 5150, Macintosh, RC759 Piccoline)
RetroArch - JavaScript port of RetroArch (bundles Gambatte (Gameboy), Genesis Plus GX, Handy (Lynx), Snes9x Next, VBA Next (GameBoy Advance), Tyrquake and FinalBurn Alpha)
RetroWeb - collection of JavaScript emulators and boot media, including Apple-IIe (VisiCalc), Macintosh (System 1.0), Atari 1040ST, Commodore 64, Amiga 500 (Workbench 1.3), IBM PC Model 5150 (PC-DOS, CP/M-86, Cassette Basic), IBM PC XT (DOS, GEM 1.2, VisiCalc, Windows 1.01, 8088 Corruption demo), RC759 Piccoline (Eliza, Bil-simulation, Concurrent CP/M-86), TRS-80.
YAKC - Z1013, Z9001, KC85/2 family, Speccy, CPC, Acorn Atom, C64, with integrated debugging UI (source)
Tiny Emulators - based on the same chip- and system-emulator source code as YAKC, but as minimal WASM apps without fluff (source)
EmulatorJS - Self-hosted emulator for various-systems.

PC Emulators

Em-DOSBox - An Emscripten port of DOSBox (Demo)
Halfix - x86 PC emulator that runs both natively and in the browser, via WebAssembly (Demo 1, Demo2)
js-dos - WebAssembly port of DOSBox (fork of Em-DOSBox with better js API) (Demo,Source)
JS/Linux - JavaScript PC emulator
JsDOSBox - JavaScript PC DOS emulator (Source)
PCjs - IBM PC Model 5150 emulator (Source)
QemuJS - An Emscripten port of QEMU (Demo)
Virtual x86 - x86 virtualization in your browser, recompiling x86 to wasm on the fly (Source)
jemul8 - An object-oriented JavaScript x86 emulator for Node.js and the Browser (Source)
jsbochs - Bochs PC emulator for the Browser (Source)
Boxedwine - An emulator that runs Windows applications using Wine and emulating a Linux kernel and CPU (Source)

Bare CPUs

8008 running SCELBAL by Mark G. Arnold. ("SCELBAL is the only open-source, floating-point, high-level language ever implemented on the 8008")
8080 CPU emulator - Intel 8080 CPU emulator running Space Invaders ROM (Source)
AVR8js - AVR architecture emulator, capable of running Arduino code (source)
EMF Arcade Invaders - EMF-based 8080 Emulator with Space Invaders ROM - by Steven Goodwin (@MarquisdeGeek) (Source)
8086tiny running FreeDOS - An Emscriptem port of Adrian Cable's 8086tiny. Source, and other emulators ported by Clay Shippy, at https://github.com/tecan/emscripten-projects.
Angel - JavaScript RISC-V ISA simulator booting Linux in a web-browser
Angular 2 6502 written with TypeScript and Angular 2, by Jeremy Likness
ARM-js - An ARM emulator written in JavaScript (Source)
ASM80 - Online assembler for 8-bit microprocessors by Martin Malý. Includes emulation of several machines: 8080, Z80, 6502, 6809. (Sources)
Basic MIPS functional simulator by Mianzhi Wang (morriswmz). (Source)
Easy6502 - JavaScript 6502 tutorial and emulator (Source)
EduMIPS64 - Educational MIPS64 CPU, ported from Java by Andrea Spadaccini using GWT (see blog here.) (Source)
FRISCjs - an 8-register educational RISC from the University of Zagreb, with both assembler and front panel, by Ivan Žužak. Source
Imaginary 6502 - 6502 Emulator and Assembler
Intel 4004 emulator - by Maciej Szyc. Includes assembler and disassembler.
Intel 8080 CPU Emulator - Emulates a minimal Intel 8080 Microcomputer that runs CP/M
JavaScript 8080 Emulator - 8080 arcade game emulator in JavaScript
Mipsdis - MIPS disassembler that runs in the browser
RISC Relay Computer - Relay based computer project with a 16 bit RISC CPU. Emulator includes an assembler and source for a calculator program. By RJH. See website.
RISCVEMU - RISC-V emulator boots 64-bit Linux. By Fabrice Bellard.
RP2040js - Raspberry Pi Pico (RP2040 / Arm Cortex-M0+) emulator with C/C++/MicroPython/CircuitPython support (Source)
Simple 8-bit Assembler Simulator - Provides a simplified assembler syntax (based on NASM) and is simulating a x86 like CPU (Source)
uARM.wasm - ARMv5TE emulator running Linux in browsers (Source)
Unicorn.js - The Unicorn emulator framework, now available for JavaScript (Source)
Visual ARM1 - JavaScript/WebGL for ARM's first CPU, modelling 25000 transistors at switch level and animating the original chip layout - in 3D. See the blog post
Visual 6502 - JavaScript simulator for the 6502 CPU, modelling thousands of transistors at switch level and animating the original chip layout. See also expert mode.
Visual 6800 - JavaScript simulator for the Motorola 6800 CPU, modelling thousands of transistors at switch level and animating the original chip layout.
Visual Z80 - JavaScript simulator for the Z80 CPU, modelling thousands of transistors at switch level and animating the original chip layout.
Visulator - x86 machine emulator that visualizes how each instruction is processed (Source)
YAMD - Yet Another MIPS Debugger (Source)
jor1k - OpenRISC OR1K JavaScript emulator running Linux with network support (Source)
jslm32 - JavaScript LatticeMico32 emulator running Linux (Source)
ZUSIE - JavaScript simulation of Fredrik Andersson's homebrew relay machine inspired by Zuse's machines.

Early machines

Babbage's Difference Engine (First funded 1823, first full build in 1855, first full rebuild in 1991)
Babbage's Analytical Engine in JavaScript, by John Walker. (First described 1837, never completed, not yet rebuilt.) (Documentation)
Turing machine simulated in JavaScript. See here for more information. (1936)
Z1 machine's adder in 3D JavaScript/WebGL interactive simulation of the mechanical adder of Zuse's first machine. By Jakob Mischek (Source) (1938)
Z3 machine's adder - ripple-carry electromechanical adder simulated in JavaScript, by Henry Raymond, Patrick Seewald and Vijeinath Tissaveerasingham. Explanation (1941)
JsSSEM - Manchester Small-Scale Experimental Machine emulator (Also check Computer/zero which is very loosely based on the SSEM, and its tutorial) (1948)
C88 - C88 computer simulation (The Homebrew CPU inspired by the SSEM) (1948)
EDSAC on Browser - by NISHIO Hirokazu (Programming guide) (1949)
EMF Elliott - EMF-based Elliott Emulator - by Steven Goodwin (@MarquisdeGeek) (Source)
WITCH Emulator - The Harwell Dekatron Machine, by Justin King. (Source and example programs) (1951)
UNIVAC I emulator - JavaScript emulator by Norbert Landsteiner (1951)
ElectroData/Burroughs Datatron 205 Emulator - by Paul Kimpel (Source) (1954)
TX-0 emulator by @wizforest, including several programs from the time. (Instructions) (1956)
Mailüfterl - JavaScript emulator by Norbert Kehrer (1958)
Setun (Russian) and English (archived) - JavaScript emulator by Обухов Александр. Ternary machine from Soviet Union (1958)
Digi-Comp 1 (previously) - educational sliding-rods plastic computer. Emulator by Larry Groebe and Kevin Williams. (1963)
Digi-Comp II - educational falling-marbles computer. Emulator by Joda Redfearn. (1965)
Burroughs B5500 emulator - Burroughs B5500 emulator in JavaScript (Source) (1964)
Apollo Guidance Computer - Moonjs a port by Shahriar Iravanian of Ronald Burkey's Virtual AGC. (1966)
BESM-6 - with examples in Algol, Fortran, and assembler. By Leonid A. Broukhis and Michael Yaroslavtsev. More here. (1968)
CARDIAC - Bell Labs' CARDIAC cardboard computer from 1969. Instructions (1969)
Kenbak-1 - John Blankenbaker's TTL-based 256byte personal computer. More information (1970)
Ordinapoche - A paper computer from France, invented 1969, popularised in 1981 and 1985. (More here and see also the 1981 magazine)

Calculator emulators

Microcode-level calculators

HP21u, HP25u, and HP29u - by Greg Sydney-Smith
HP-35 - bug-compatible emulator by Ashley Feniello explained here using Eric Smith's and Jacques Laporte's work
HP-35, HP-45, HP-55, HP-65, HP-80 - collection of HP Classics, based on Feniello's work, by Francois Roulet
HP-45 - statically recompiled ROM by Norbert Kehrer
jsEmu48 - emscripten port by Julien Meyer of HP EMU By Daniel Nilsson. (Source)
HP-55, HP-65 and HP-67 - with extra debug menu, by Greg Sydney-Smith
мк-61 - Elektronika's programmable calculators MK-61, Б3-34, МК-54, and МК-56, also the Феликс-М (Felix M) arithmometer, a slide rule and an abacus. By Felix Lazarev, Andrey_emu, Sergey Tarasov and others.
Sinclair Scientific and TI-1500 - calculator simulations including full description of the algorithms and the reverse-engineering process. By Ken Shirriff. Further work by Phil Mainwaring shows Sinclair Cambridge, TI-1500 and Sinclair Scientific, each using different customisations of TI's 080x chip.
TI-42 "MBA" Programmable Calculator by Jeff Parsons (PCjs)
TI-55 by Jeff Parsons (PCjs)
TI-57 Programmable Calculator by Jeff Parsons (PCjs)
TI-92 Plus emulator - JavaScript emulator for the TI-92 Plus
JavaScript TI-89 / TI-92+ / TI-V200 / TI-89T emulator - by Patrick Davidson and Lionel Debroux

Workalike calculators

HP-11C, HP-12C Platinum, HP-16C - by Elvis Pfützenreuter
HP-16C (Jovial RPN) - by Bill Foote
HP-15C - by Greg Hewgill. (Source)
HP-21 and HP-29 by Greg Sydney-Smith (See here and here)
HP-25 - by John Clenance
HP-35 - JavaScript emulator by Neil Fraser
HP-35 SOS - modified HP-35 with stack overflow sensing LED, by Hans Klaver, based on Fraser's work
HP-48 - JavaScript implementation of the most commonly used HP-48 functions. More info here, by Josh Poley
Olivetti Programma 101 - JavaScript emulation of the first commercial programmable desktop computer, by "Fabioamd87". Source on GitHub
Sinclair Cambridge Programmable by Nigel Bromley. (Source here.)

Miscellaneous

C1Pjs - JavaScript simulation of the Challenger 1P (PCjs)
Canon Cat (in JSMess) - Jef Raskin's Forth-capable 68000-based word processor. (Instructions and more info)
CFT - JavaScript simulation of Alexios Chouchoulas' 16-bit homebrew TTL machine. (More information including documentation and a video.)
Chip-8 virtual machine by Alexander Dickson - see blog entry
Chip-8 virtual machine by Brian Milton (Source may target several CPUs)
Chip8 1k - a code-golfed chip 8 emulator in 1k by Maxime Euzière and others
EMF Chip 8 - EMF-based Elliott Emulator - by Steven Goodwin (@MarquisdeGeek) (Source)
EMF Megaprocessor - EMF-based Megaprocessor Emulator - by Steven Goodwin (@MarquisdeGeek) of the room-sized machine built by James Newman and housed in the Museum of Computing History, in Cambridge, England. (Source)
Merry8 - JavaScript Chip-8 emulator by Yifeng Wang
Compucolor II Emulator - JavaScript Compucolor II Emulator
Compukit UK101 - by David Stevenson
ContrAltoJS - Pure JavaScript implementation of the ContrAlto Xerox Alto emulator (Source)
COSMAC Elf-ish - simulator by William Donnelly
DCMO5 Online - Thomson MO5 JavaScript emulator
Dodo Playground - IDE and simulator for 6502-based Dodo homebrew game system by Peter Noyes
EMF Dragon - EMF-based Dragon Emulator - by Steven Goodwin (@MarquisdeGeek)
EMF Jupiter Ace - EMF-based ZX80 Emulator - by Steven Goodwin (@MarquisdeGeek) (Source)
Enterprise-128 JavaScript Emulator - by Gábor Lénárt "LGB", based on JSSpeccy
ESP8266 Game Engine - a console-game-oriented virtual machine running on ESP8266, by Corax. (Source)
Gigatron - emulator of the present-day TTL console computer with Tiny Basic and games. Also Wozmon on a nested emulation of 6502. (Website)
Hack - emulator of the computer from nand2tetris, by diversen. (Source.)
Heathkit ET3400 - by Phil Mainwaring. Click "Do" then "0000". (Instructions)
IBM 5110 Emulator by Norbert Kehrer runs Basic or APL.
JS99'er - TI-99/4A emulator written in JavaScript (Source)
jsH89 - Heathkit H89 emulator (runs CP/M) by Mark Garlanger
JSGS - Experimental JavaScript implementation of the Pico-8 fantasy console (Source)
jsMSX - The first MSX emulator 100% written in JavaScript
JsPspEmu - JavaScript PSP emulator (Source)
JSVecX - JavaScript port of the VecX Vectrex emulator
jupiler - Jupiter Ace emulator written in JavaScript (Source)
KM-Z80 web emulator for Sharp MZ-80K, by Katsumi Morimatsu. GOTO $1200 to start KM-BASIC. (More information)
laser500emu emulator for Video Technology (VTech) Laser 350/500/700, by Antonino Porcino.
Little Man Computer a minimal CPU for teaching - emulator by Matthew Krutar. (Background)
Little Man Computer a minimal CPU for teaching - emulator by Paul Hankin. (Background)
Little Man Computer a minimal CPU for teaching - emulator by Peter Higginson. (Background)
Machine in a machine - Turing Machine Implementation in 1k from the JS1k competition
Marmmodore-1K - minimal 8-bit computer in 1k by Felipe Alfonso
NanoWasp - A MicroBee emulator
Nascom 2 emulator by Tommy Thorn. (J to start Basic) (Source)
One Instruction Set Computer (OISC) by Peter Crampton, presented by Brian L. Stuart. (Explanation)
Orao - Orao emulator by Hrvoje Cavrak (More information)
Oricutron - An emulator for the ORIC series of home computers, by Peter Gordon (Source)
PC-01 Lviv - An emulator for the PC-01 Lviv (Ukrainian home computer) (Source)
RISC Simulator - RISC Simulator with Fetch/Execute and register based CPU model, by Peter Higginson
RockyJS - Pebble watch interpreter/emulator
Radio-86RK Radio-86RK emulator in JavaScript (Intel 8080 based 8-bit Russian home computer) (Source)
Setunka - Ternary computing for the browser
SAP-1 JavaScript emulation of the Simple As Possible TTL machine from Malvino's book, Digital Computer Electronics. By Kenneth Ellis McCall. (Source)
Tejotron - Virtual breadboard, inspired by Ben Eater's 6502 computer
Turbo Pascal - A web-based Pascal compiler that runs a subset of Turbo Pascal 5.5 code
Vector06js - Vector-06C (AKA Вектор-06Ц) JavaScript emulator by Viacheslav Slavinsky. Also runnable here. (Source.)
Virt.js - JavaScript emulation library (Source)
Visual Computer a minimal CPU for teaching by Shimon Schocken. (Web site)
WebMSX - WebMSX, or simply WMSX, is a new MSX emulator designed for the Web (Source)
Wireworld computer - JavaScript port by Salvatore Aiello of the prime-generating computer implemented in the Wireworld cellular automaton, as described here.
WPCEmu - Williams Pinball Emulator by Michael Vogt

Adventure Game Engines

Emscripten ScummVM - Emscripten fork of the ScummVM engine
IFVMS - Infocom/Inform Web interpreter
Parchment - Infocom/Inform Web interpreter
ZZTJS - ZZT game engine in JavaScript
ngPAWS - Professional Adventure Writer (PAW) Web interpreter