Microsoft makes MS-DOS source code and first Word version public

Together with an American museum, Microsoft has made public the source code of MS-DOS 1.1 and 2.0, as well as that of the first Word version for Windows. As a result, future generations should be able to understand ‘the roots of the PC’.

The source code of the Microsoft software can be downloaded from the Computer History Museum website. Although the source code is made public, it may not be used indefinitely to create derivative works and Microsoft retains the copyright. Earlier, the Computer History Museum already made the source code of DOS for the Apple II, QuickDraw and MacPaint and Adobe Photoshop and Adobe Photoshop public.

The 1.1 source code consists of seven files of assembly code and is accompanied by an email from Tim Paterson, the original author of MS-DOS. The 2.0 source code consists of 118 files, which consists largely of assembly code, as well as the necessary documentation. The Word for Windows source zip file contains mostly C and C++ code.

An employee of the museum already had the source code for MS-DOS 2.0, but needed Microsoft’s permission to publish the source code. Finding the source code for MS-DOS 1.1 was more difficult: Microsoft didn’t have it either. Eventually, the museum received the source code from Paterson. Microsoft still had the source code of the first Word for Windows version.

The first version of DOS wasn’t even developed by Microsoft itself, but was licensed from Seattle Computer Products, another technology company based in the same region as Microsoft. Version 1.1 only supported floppy disks; version 2.0, released a year later, introduced support for folders and hard drives.

Word for Windows was not the first Word version: it came out in 1983 for MS-DOS. Nevertheless, that Word version did not really become popular. It was only with the introduction of Word for Windows that Microsoft managed to knock the market leader WordPerfect off the throne.