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About JavaScript Machines
The JavaScript Machines Project (originally at jsmachines.net) is a collection of computer simulations written in JavaScript. It has now been released on GitHub as the PCjs Project, a copy of which is hosted here at [{{ site.pcjs_domain }}]({{ site.url }}/).
The goals of the project are to create fast, full-featured simulations of classic computer hardware, help people understand how these early machines worked, make it easy to experiment with different machine configurations, and provide a platform for running and analyzing old computer software.
The simulations are written entirely in JavaScript and run well in a variety of web browsers, on both desktop and mobile devices. Machines are created with simple XML files that define a set of machine components, along with the features that each component should enable. More details about machine definitions and component capabilities can be found in the Documentation.
Emulating the Challenger 1P
The first JavaScript Machines simulation was C1Pjs, a simulation of the Challenger 1P, which was a 6502-based microcomputer introduced by Ohio Scientific in 1978.
C1Pjs v1.0 was released in July 2012, first on ecpsim.org and cpusim.org, then on jsmachines.net, and finally [{{ site.pcjs_domain }}]({{ site.url }}/). More information about the first release of C1Pjs was also posted on the OSI Discussion Forum at osiweb.org.
Emulating the IBM PC
The next JavaScript Machines simulation was PCjs, which simulates the original IBM PC, IBM PC XT, and IBM PC AT.
PCjs emulates the Intel 8088 and 80286 CPUs, as well as IBM Monochrome Display Adapter (MDA), Color Graphics Adapter (CGA), and Enhanced Graphics Adapter (EGA) video cards, along with assorted motherboard and expansion bus components. It also includes an optional Debugger and a user-configurable Control Panel.
PCjs v1.0 was released on jsmachines.net in late 2012, and the JavaScript Machines Project, with its second full-featured machine emulation, was launched.
Read About PCjs to learn more about its history, features, and upcoming improvements.
Migrating to Node: The PCjs Project
The JavaScript Machines Project was migrated to a Node.js web server in 2014, and became the PCjs Project.
The goals included:
- Using JavaScript exclusively, for both client and server development
- Leveraging the Node.js web server to provide more sophisticated I/O capabilities
- Improving overall website design, including structure, appearance and responsiveness
The PCjs web server includes a number of custom Node modules that provide many of the same server-side features found on jsmachines.net, including new ROM and disk image conversion APIs, and a Markdown module that supports a subset of the Markdown syntax, including extensions to the link syntax that make it easy to embed C1Pjs and PCjs machine files in Markdown documents.
License
The PCjs Project is now an open source project on GitHub. All published portions are free for redistribution and/or modification under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
You are required to include the following copyright notice, with a link to [{{ site.pcjs_domain }}]({{ site.url }}/):
[PCjs]({{ site.url }}/) © 2012-2015 by Jeff Parsons (@jeffpar)
in every source code file of every copy or modified version of this work, and to display that notice on every web page or computer that runs any version of this software.
See LICENSE for details.
More Information
If you have questions or run into any problems, feel free to tweet or email.