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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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Download FreeDOS 1.2 »

What’s New

FreeDOS FDISK 1.3.4

Tom Ehlert has released an update to FreeDOS FDISK. This version fixes a serious bug "when creating logical drives, using 'use maximum size', FDISK would allow to create an additional partition of size 0, trashing the complete disk partitioning." This bug appears to be resolved in FDISK 1.3.4. Please download the new version and test. You can download it from Tom's website as {zip file} or mirrored in the FreeDOS files archive under /dos/fdisk on ibiblio. Thanks, Tom!

DOS32pae - a PAE experiment

Dos32pae is a program that is supposed to be added (by a linker) to a 32-bit PE binary - a so-called "stub". The stub is executed when the binary is launched in DOS. As Japheth describes it, "Using PAE paging, this tiny 'DOS extender' - although 32-bit and thus limited to 4GB of address space - is able to use huge amounts of memory. There's a sample supplied, Alloc.asm, that demonstrates this feature, backfilling 4092 MB of "linear" memory with physical memory allocated via XMS v3.5 beyond the 4 GB barrier." Dos32pae is under the open source MIT license. You can find it at Dos32pae's GitHub

lDebug release 1

lDebug is a 86-DOS debugger similar to the MS-DOS Debug tool. lDebug is based on DEBUG/X 1.13 to 1.18 as released by Japheth, whose work was released as Public Domain. It features DPMI client support for 32-bit and 16-bit segments, a 686-level assembler and disassembler, an expression evaluator, an InDOS and a bootloaded mode, script file reading, serial port I/O, permanent breakpoints, conditional tracing, buffered tracing, and auto-repetition of some commands. There is also a symbolic debugging branch being developed. The lDebug manual in html, plain text and PDF is available online. The main website is at ecm's webbed site with links to the source code and file releases. We have also mirrored this release at the FreeDOS files archive under /dos/debug/ldebug.

libsixteen (aka lib16)

SuperIlu writes about a new project. Libsixteen provides helper functions for VGA mode 0x13 graphics, BMP loading/saving, mouse pointers and IPX networking. It was written just for fun using OpenWatcom. Libsixteen is available under the GNU GPL and MIT license, although the "Computer" and "Magic 5" fonts are under a different font license with some restrictions. You can find it at Libsixteen on GitHub.

Mark the date - February virtual get-together

When we had our last virtual get-together in January, we wanted to do it again in February. Mark your calendars for next Sunday, February 21, 2021 at 11am US/Central. Use your favorite timezone converter to find your local time. Just like last time, we'll hold the meeting via BlueJeans. I use BlueJeans for my consulting and training, so I already have things set up there. You can connect to the meeting directly from your browser without a client, or you can download the BlueJeans Meetings client at your preference. I'll share the meeting link on the email list, and on the website, and on Twitter + Facebook when the get-together starts.

Thanks to everyone for joining us on the virtual get-together! Conversation ranged from social talk to FreeDOS 1.3 RC4 planning, and even some live debugging. It was a lot of fun, and we'll definitely do this again next month.

Looking for more FreeDOS news? See also: FreeDOS in the news | timeline of FreeDOS history