Microsoft and IBM's DOS operating system is a milestone in the history of personal computing, and it's just as important that we dig into what makes it tick. This is why both companies have released the source code for certain versions, including MS-DOS 1.25, 2.11, and, as yet, 4.0. The 1988 release added support for partitions above 32 megabytes (yes, megabytes, as in “smaller than a modern digital camera image”).

Microsoft and IBM released the updated code under the open source MIT license. Earlier this month. Microsoft said it's about the “spirit of open innovation,” but not everyone is happy with how open the updated version of DOS is. Michal Necasek, a software engineer and historian, has documented some of the problems. on the os2 museum blog. This process has left the code, in Nikacek's words, “distorted”.

The biggest problem appears to be that Microsoft released the source code as git files, not their actual binary files. It's probably a natural impulse to convert relatively primitive data into text format with modern code editors…but it also means that software and hardware tools designed for the original operating system can't handle it.

It certainly doesn't help that the git files also lack timestamps, which (according to the comments on the story and Tom's Hardware picked up) is a matter of data protection policy. The code itself may be an updated MS-DOS 4.01 as early as possible, and not the actual release. It is possible that some of these issues will be resolved, as Microsoft can only release the original files in their original format. But it's not a high priority for a company to pay much attention to. Sending more ads in Windows 11.

In a historical sense, the bungled release of DOS 4.0's open source files is about right. Back in 1988, DOS 4.0 was like the Windows 8 of its era, disliked by a vocal segment of users because of a larger memory footprint and more bugs than previous versions.