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Welcome to FreeDOS

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FreeDOS is an open source DOS-compatible operating system that you can use to play classic DOS games, run legacy business software, or develop embedded systems. Any program that works on MS-DOS should also run on FreeDOS.
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You can play your favorite DOS games on FreeDOS. And there are a lot of great classic games to play: Wolfenstein 3D, Doom, Commander Keen, Rise of the Triad, Jill of the Jungle, Duke Nukem, and many others!
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Need to recover data from an old business program? Or maybe you need to run a report from your old finance system? Just install your legacy software under FreeDOS, and you’ll be good to go!
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Many embedded systems run on DOS, although modern systems may instead run on Linux. If you support an older embedded system, you might be running DOS. And FreeDOS can fit in very well.

FreeDOS is open source software! It doesn’t cost anything to download and use FreeDOS. You can also share FreeDOS for others to enjoy! And you can view and edit our source code, because all FreeDOS programs are distributed under the GNU General Public License or a similar open source software license.

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Latest Updates

VERIFY and CLS re-implementation in Assembly

The best way to explore programming is to write a new version of something that exists. Javier Gutiérrez Chamorro has been experimenting with re-implementing tools in pure assembler. "I am not sure if it could be useful for anyone, but I have just reimplemented VERIFY.COM by Peter Mikalajunas, 1995. With this main .COM executable gets reduced from 5,444 bytes to just 653 bytes. My implementation works with ON and OFF, but also with 1 or 0." And: "CLS reproduces the same CLS.C behaviour, including the redirection detection, but instead of a 9,080 bytes CLS.EXE it creates a 380 bytes program." You can find these at CLS on SourceForge and VERIFY on SourceForge

OldTrek spaceship games for DOS

Thanks to SuperIlu for making these two games written in C compile with DJGPP and create binary releases for DOS. startrek aka SUPER STARTREK by Bob Leedom (C port by Chris Nystrom), and Trek by Eric P Allman. The original source can be found on the Wayback archive for 'startrek'. The updated versions are on OldTrek at GitHub.

ISLOADED hardware test tool

Thanks to Bret Johnson for sharing ISLOADED, a tool that tests hardare and system capability, for use in batch files by returning an Errorlevel. The source code is released under the UnLicense, a form of public domain. Download it from the FreeDOS Files Archive at Ibiblio, under /files/util/system

Example usage: "ISLOADED VGA" will return Errorlevel 0 if the video card is compatible with VGA, or 1 if not. If you test for more than one thing, it returns Errorlevel 255 and displays info to the screen. "ISLOADED VideoCard" will return Errorlevel 255 for any video card, but will also tell you what type of video card you have. ISLOADED also includes CPU tests (80286, 80386, etc). The CPU tests are "equal to or greater than." "ISLOADED 80286" will return Errorlevel 0 if the CPU is 80286 or higher, or 1 if it is an 8086/8088/80186. "ISLOADED CPU" will return Errorlevel 255 and display the CPU type.

VMSMOUNT 0.6 preview

Eduardo made a preview release of the upcoming VMSMOUNT 0.6 version, so that anyone who wants to can try it and report any feedback. There are a lot of changes in this version, including: + It is now possible to add, remove or modify shared folders while the VM is running + if the new VMCHCPD.SYS device driver is installed, code page changes using the CHCP command will load the corresponding unicode conversion table. You can get the sources, binaries and a FreeDOS package from VMSMOUNT at GitHub, or more directly at VMSMOUNT 0.6 Preview on GitHub.

Updated mTCP Telnet client

mTCP is a set of TCP/IP applications for personal computers running FreeDOS and other flavors of DOS. Michael B. Brutman has released a new version of the Telnet client. This special version of the Telnet client adds support for rendering RLE graphics. View graphics files online right in the Telnet client like you are connected to Compuserve back in 1985. Find more information at the mTCP website, or more directly from the mTCP Telnet page.

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