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Starting MS-DOS...

Do yous dream of CONFIG.SYS and find yourself doodling "DOS=HIGH,UMB" on scraps of paper during moments of boredom? If then, contempo news from Microsoft volition likely make your twenty-four hours. Microsoft is re-open-sourcing MS-DOS on GitHub. As implied, this isn't the commencement fourth dimension the OS has been released as an open-source project, but according to Microsoft, information technology's now much easier to use the data. The visitor writes, "Today, we're re-open-sourcing MS-DOS on GitHub. Why? Because it'due south much easier to find, read, and refer to MS-DOS source files if they're in a GitHub repo than in the original downloadable compressed archive file."

Two unlike versions of DOS have been open-sourced — DOS ane.25 and DOS ii.0. DOS 1.25 was used equally the basis for all of the non-IBM versions of DOS, while MS-DOS version 2.0 included a number of significant features such equally IBM XT hard bulldoze support (upwardly to 32MB formatted), user-installable device drivers, non-multi-tasking child processes, and ANSI.SYS. DOS two.0 was also the first version to support 5.25-inch disks in capacities of 180KB and 360KB.

DOS-1

Microsoft's weblog post notes:

  • All the source for MS-DOS i.25 and ii.0 was written in 8086 assembly code
  • The source code for the initial release of 86-DOS dates from effectually December 29th 1980
  • The MS-DOS 1.25 code dates from around May 9th 1983, and is comprised of just 7 source files, including the original MS-DOS Command-Line beat out – COMMAND.ASM!
  • MS-DOS 2.0 dates from around Baronial 3rd 1983, and grew considerably in sophistication (and team size), and is comprised of 100 .ASM files
  • There are some interesting documentation (.TXT, .DOC) files interspersed with the source and object files – many are well worth a read, as are many of the source code comments!

Microsoft's decision to open source MS-DOS like this might non seem especially of import, given the plethora of alternatives on the market place. FreeDOS remains in agile development, while utilities like DOSBox tin can emulate DOS finer. And then there's the fact that even every bit DOS versions become, MS-DOS 2.0 is ancient — I got started with MS-DOS iii.3 in 1987, DOS 6.22 was the concluding version released at retail, and the last version to formally ship with Windows ME was 8.0. But DOS is besides a critical component of the history of the PC and its development mirrors the deployment of features and technology in much of the marketplace through the 1980s.

Microsoft asks that users refrain from Pull Requests that suggest source file modification, as it intends to continue source files static.

Now Read: MS-DOS is 30 years quondam today, And then, yesterday someone asked me 'What is DOS?, and Microsoft releases celebrated MS-DOS and Word source lawmaking to the public