This is how to run Windows 1.01 in your browser and relive memories

Some developers are trying to keep the past alive with full-featured emulators that run in your browser. You can now run Windows 1.01 in your web browser, thanks to the surprising power and flexibility of JavaScript.

Windows 1.01 was released in 1985 as one of the first operating systems with a graphical user interface (GUI), and went on to become the foundation for the Microsoft empire that keeps the brand alive today. With limited multitasking abilities and barebones graphics, the operating system sat on top of MS-DOS. Windows 1.01 allowed you to multitask DOS applications through a rudimentary taskbar. Further, Windows 1.01 did come with some classic programs like Notepad, MS Paint and Writer.

Powered by PCjs, the browser-based version of Windows 1.01 is an IBM PC XT (Model 5160) emulator written in JavaScript. All major browsers including Safari on iOS and Chrome on Android support the emulator. Basically, PCjs emulates in software the wholeness of the IBM PC ROM BIOS and MDA font ROM.

While the hardware of the emulated machine is highly configurable via XML, the PCjs emulates the Intel 8088 CPU at 4.77MHz, 256KB of RAM, and CGA graphics in the case of the Windows 1.01 machine. It looks like that PCjs is primarily interested in emulating all of the features in IBM PC BIOS that Windows 1.01 makes calls to, rather than emulating the specific hardware features of the IBM PC XT.

Windows 3 and 3.11 were the first versions of Windows that were widely used by almost everyone. While Windows 1.01 was mostly noticeable for bringing the concept of device drivers that let programs to easily interact/invoke with hardware (graphics cards, mice, printers, etc.) which previously could only be reached via the BIOS or bare metal. Windows 1 was not a huge success at the time, nor was its contemporary, the Apple Lisa II.

After Windows 1.01 emulator, you may also like to try out some other disk images that work with PCjs, such as DONKEY.BAS, Zork 1 for the IBM PC, or a very early DOS game co-written by Bill Gates. Using a JavaScript port of PCE (PC-Emulator), you can also run Windows 3 and Mac OS System 7 in your browser.

While it may look awesome, reproducing some 30-year-old software and hardware in JavaScript is fairly very simple. JavaScript itself is going through a revival process, with libraries such as asm.js allowing for JS performance that is enticingly close to native, compiled code.

To try Windows 1.01 in your browser, visit here.