Microsoft recently made the MS DOS 4 source code public on GitHub. MS-DOS 4 (acronym for Microsoft Disk Operating System, version 4) is an operating system that dates back to 1988.
As soon as it was released, the MS DOS version 4.0 operating system was quite buggy and this forced users to prefer the previous version. To fix the bugs, Microsoft later released the next version 4.01.
IBM DOS and MS DOS
It is important to note that IBM (International Business Machine) had its own version of DOS, known simply as IBM DOS. Although there were differences between IBM DOS and MS-DOS, they were essentially similar in functionality and compatibility. This similarity was no coincidence: IBM and Microsoft had a close partnership.
Installing IBM DOS on an IBM PS/2 Model 30 286
In a recent experiment, I decided to install IBM DOS 4.0 on my IBM PS/2 Model 30 286.
The installation process turned out to be a little more challenging than expected. In my first attempt, I encountered several compatibility issues and errors that prevented the operating system from installing properly.
Subsequently, I formatted the hard disk (whose format was strangely not recognized by IBM DOS 4.0). I then tried installing the operating system again and this time, armed with patience, I succeeded! The second attempt proved to be a success.
An interesting "news" (the quotation marks are a must, considering that almost 40 years have passed!), is the presence of DOSSHELL, which starts automatically when the computer is turned on.
