LensKey is a Lenslok™ decoder for Windows 95 or later. It emulates the function of the plastic lens, unscrambling an on-screen pattern to reveal a 2 character security code.

BizHawk is a A multi-system emulator written in C#. BizHawk provides nice features for casual gamers such as full screen, and joypad support in addition to full rerecording and debugging tools for all system cores.

This is the organizing page for the Javascript Mess Project, an effort to port the MAME and MESS emulators to Javascript.

Online 6502 emulator in Javascript with source

Bacteria is the javascript port of the smallest spectrum emulator, Bacteria. The real size is about 20K, but the 16K Rom is included, so the virtual size is ¡¡¡ only 4Kb !!!

This is homepage of Qaop, a ZX Spectrum emulator. Qaop is a Java applet which can be embedded on a page, but can also be run as a simple application.

A multiplayer Atari 2600 emulator written in pure Java with no external libs.

ZX360 emulates 48K ZX Spectrum for the Xbox 360 using the XNA platform.

Virtu is an Apple IIe emulator for the .NET Framework using C# with Silverlight, WPF, and XNA.

dcpu-semu is a DPU emulator written for DCPU computers.

JavaScript DCPU-16 assembler, emulator & disassembler

DCPU-16 Studio is an assembler, disassembler, emulator and debugger for the virtual computers in Mojang's upcoming 0x10c game.

DCPU-16 Studio provides a graphical interface for those who want to experiment with writing DCPU-16 programs. It also includes some documentation on the DCPU-16 architecture as described in the DCPU-16 specifications.

Chip16 Development Kit will include an IDE, Emulator, Debugger and Compiler for Chip16 system.

PSX Emulator with Rerecording features adapted from the PCSX GPU core

PSXjin is an overhaul of the outdated pcsx-rr branch of PCSX. It includes a new SPU and integrated components rather than the use of plugins (though currently input plugins are still required and packaged with PSXjin). In addition there is an overhaul of the GUI components & features, including the removal of the 2 window design inherent in PCSX emulators.

PSXjin is a rerecording emulator and its primary focus is to facilitate the making of Tool-assisted Speedruns. When possible & time permitting it will also support features for casual gaming.

Laying The Groundwork For An Emulator - Error Handling

Emulation Document Part The Second - Memory Emulation

Emulation Document - Part 1

Good documentation on 6502 CPU

Good portable z80 emulation library written in C

Simulate 6502-based microcomputer systems in Python.

Emulating your favorite system to play games is easier than you think depending on the system you’re trying to emulate. This document is intended to give you the general idea of building an emulator. To help you understand the concepts more I will give specific examples to the NES emulator that I have been working on this semester at California State University of Long Beach.

This is a GameBoy Color emulator written in JavaScript. This page takes advantage of modern browser capabilities like HTML5 and JIT engines to provide a desktop emulator experience right inside a webpage without the use of plugins (If you disable plugins on a browser, the graphics will still work, though the audio might stop working for users that need flash to run the audio output).
You can either select a game from a list, or drag and drop a .gb or .gbc file into the emulator.

A detailed, step by step guide to writing an emulator.

Asm.Net is a assembly emulator which is developed in the language C#

Mash16 is a cross-platform Chip16 emulator written in C++.

XNACPC is an Amstrad CPC emulator for the Xbox 360 and PC, written using C# and XNA.

BytePusher is a minimalist virtual machine invented by user:Javamannen in 2010. You can think of it as a simplified CHIP-8 with bigger memory, bigger screen with colors, and sampled sound. BytePusher has a ByteByteJump one-instruction CPU. The barebones hardware abstraction layer provides only memory-mapped pixel and audiosample buffers, keystates and a fixed framerate.

OSIC VM is a virtual machine simulation of a one instruction set CPU and related devices.

ApplePy is an emulator, written in Python, of both the 6502 chip and other hardware aspects of the Apple ][ computer.

Nintendulator is an open source Win32 NES emulator written in C++. The original goal was to emulate the NES down to its hardware quirks; though it's fallen behind over the years, recent builds have caught up once again and can emulate certain behaviors most other emulators neglect to handle. However, this emulation precision comes at a price - a 1500MHz (estimated) or faster CPU is required to emulate at full speed.

Jpcsp is the most advanced PlayStation Portable emulator, allowing you to play your PSP games on a PC. Jpcsp has been started in July 2008 and is developed by a small but active team.

The goal of this project is to implement an open source emulation framework with C# under .NET 2.0.  All source code is released under the LGPL license.

An Xbox1 emulator for Windows using LLE and a fairly unique method of direct code execution/static rec. This project was started out of boredom one day, and it started to evolve into something serious.

Fake86 is an 8086 PC emulator written in C. It is written from scratch, including the CPU core and has been under development since October 2010.

A document about the down and dirty timing of the Gameboy's video hardware.

A test ROM is a program designed specifically to test whether the platform that the program is running on is working correctly. A test ROM can be used to test the accuracy of an emulator, as well as compare the behavior of different hardware revisions.

jBacteria is the javascript port of the smallest spectrum emulator, Bacteria. The real size is about 20K, but the 16K Rom is included, so the virtual size is ¡¡¡ only 4Kb !!!

EmuFuzzer is a fuzzer for CPU emulators. EmuFuzzer "stresses" a CPU emulator with specially crafted test-cases, representing registers and memory configurations, to verify whether the CPU is properly emulated or not.

So, what is Tiny? Tiny is an assembly language for an imaginary cpu designed to help teach the concepts of assembly language. It was created by Dr. Steve Baber and Dr. Tim Baird at Harding University to use in the Assembler class. The instructions and specifications are listed here as well. All information and code that was written by them is used by permission.

A N64 emulator written in C#

The Computer History Simulation Project is a loose Internet-based collective of people interested in restoring historically significant computer hardware and software systems by simulation. The goal of the project is to create highly portable system simulators and to publish them as freeware on the Internet, with freely available copies of significant or representative software.