New DOS DPMI project? Aitor posted this note to the FreeDOS mailing list about a new DOS DPMI project: I have thought that you might find it useful to have a look at this page: http://www.wuschel.demon.co.uk/ they are developing »
Testing FreeDOS beta5 Aitor performed a number of tests on the FreeDOS Beta5 (Lara) distribution, and here is what he found: This will be the last time I try programs for a while. In the meantime, fill my mailbox »
Technote102: More testing FreeDOS Beta5 Freya performed some additional tests on the FreeDOS Beta5 (Lara) Distribution , and had this to say: Oh just remembered some things I found while playing with freedos! I may be booting dos »
HIMEM and EMM386 Recently on the FreeDOS mailing list, a user asked how HIMEM and EMM386 are able to address more than 1MB memory. These are the replies: Neato asks: I know the CPU can't *address* >1024k except in »
TurboVision as Open Source Software? Recently, on the FreeDOS mailing list, someone asked a question about the code to Borland's TurboVision and it's open-source status: The question was: Well, what I'm looking for is a graphics-type library, kind of »
Boa for DOS? Recently, a user asked this question on the FreeDOS mailing list: I am looking for the source & binaries for Boa for DOS but have been unsuccessful. Boa is a www server for DOS and would »
LaTeX under DOS? Recently on the FreeDOS mailing list, the LaTeX document preparation system came up. The question was: what LaTeX processor to use under DOS, and where to get it? Tobias writes: I got my EmTeX (=LaTeX for »
AARD compatibility Aitor has posted a bit of technical information about the AARD code in MS-DOS, which might be helpful in adding compatibility to FreeDOS: I have discovered in the technical literature something that seems to be the result »
INTERLNK In reply to a discussion on the mailing list about a replacement for MS-DOS INTERSVR and INTERLNK, Reggie pointed us to this DOS freeware that does the same thing: Reggie D David wrote: File Maven is an advanced »
Serial numbers on floppies Aitor wrote: I think someone asked how DOS creates the serial disk number, and I thought this might be useful to Brian. That's why I point out FloppySerialNumbers.txt , which might be interesting: >Does »
FreeCOM memory usage We've long recognized that FreeCOM (our command.com shell) is a bit of a memory pig. The following discussion was posted to the FreeDOS mailing list about what we might do about it: Brian E. Reifsnyder writes: »
FreeDOS CHKDSK Ralf Quint posted this recently on the FreeDOS mailing list. This was a reply to a post about searching for technical information about CHKDSK, so some helpful hackers could begin to work on a »
Memory management Lyn David Thomas posted this note to the FreeDOS mailing list asking for suggestions on memory management for FreeDOS: Hello there, it has been suggested to me that this might be a good forum for asking for »
Max disk space Given the ongoing discussion about OEM DR-DOS 7.05, here´s a tip how to maximize the disk storage space available for DR-DOS 7.03 (and earlier) to up to 8 Gb per harddisk even in multi-boot scenarios with »
FAT integrity Arkady posted this interesting bit of information to the FreeDOS mailing list about checking the FAT integrity. What I thought was great is that Arkady posted it in pseudo-code format, which I am attempting to reproduce in »
Date formats Matthias Paul posted this information to the FreeDOS mailing list about date formats, which I am reproducing here: Yes, the date format specified by DIN EN 28601 (approved in 02/1993) ([cc]yy-mm-dd) is mandantory in German offices since »
Recently, I saw this exchange on the FreeDOS mailing list How to create a new keyboard layout? As asked in the subject line. I would like to make a Dvorak keyboard layout. Also, how does one implement ASCII »
Recently, there was a discussion on the mailing list about how a DOS program can detect if it is running under Windows: I consider the environment string testing to be 100% reliable. That information came from M$ programs... Has »
Aitor has been doing some testing with the FreeDOS Beta6 pre-release and some other FreeDOS software, and has this to report: Hi all, This is the result of the testings of the Pre-Beta6 of FreeDOS. Machine: IBM PS/1 with »
On the FreeDOS mailing list , someone asked how to create a bootable CD-ROM using FreeDOS: Well my Floppy drive is dead right now and I know its easy and cheep to get a new one. But..I would »
Several people have had an opportunity to test the FreeDOS Beta6 distribution. Here is what they have to say (both good and bad): Hurraaahh !!! I have been testing Beta 6 with Kernel 2023c this afternoon and I am »
Testing FreeDOS Beta6 More people have been trying the FreeDOS Beta6 ("Midnite") distribution. Here is what they have to say: I have done some testing with FreeDOS Beta 6 and kernel 2023d and it is very stable. I experimented »
Using KSSF in the new FreeCOM I saw this discussion on the FreeDOS href="/freedos/join/"> mailing list the new FreeCOM release: Where are instructions to use them? I just tried to run KSSF to get the help screen and »
FreeDOS at work Bill Weller writes: The two programs are SLIMS (Small Library Information Management System) Machine is HP 4433 The config.sys was: The autoexec.bat was: I had a little trouble finding a compatable screensaver. »
LBA Support in FreeDOS Kernel 5/3/01 Everyone, Tonight, I was able to successfully test the read/write LBA support I added to the kernel. (I was also able to play Commander Keen, off of my hard drive, with this LBA »
UBasic - not a free alternative Anmol Narula had emailed me in April, asking if I would consider switching the FreeDOS Distribution from using bwBASIC to using UBasic. My answer is simply no. Here are my reasons: Anmol had »
FreeDOS and Norton Ghost Gareth Randall has been working to get Norton Ghost to work with FreeDOS. He has met with success. Rather than post this on the FreeDOS web site as a regular news story, I am posting »
DOS-based symbolic links Aitor has started a new project called LinkLib that will provide a standard way for DOS apps to use symbolic links. This is based on a variant of what the SEAL developers are working with. Here »
FreeDOS developer's kit Aitor has been putting some thought to how to help developers contribute to the FreeDOS Project, and has come up with a great idea! Here it is: During the last weeks I have been thinking of »
Technote: FreeDOS success and problems Roberto Mariottini has done some testing with some recent FreeDOS software, and sends us this report of his success and problems: Hello, last night I've found the time to go on ibiblio FreeDOS archives »
Technote: TDSK successes, and more information Alain writes with this report about the latest TDSK: I have installed TurboDisk 2.41 in a real life heavy duty application I have just one request for improuvement of TDISK: if the »
Alain asks: How can I detect the current setting of LASTDRIVE= ? I just made a program someone suggested in this list. I liked the idea, but I am sorry I cannot remember who had the idea ;-) The »
Booting FreeDOS using disk-on-chip There was a discussion on the FreeDOS mailing list I want to know if it's possible to install FreeDOS onto a flash RAM/ROM (like ROMDOS) on a Single Board Computer and where I can »
FreeDOS Environment Library I was leafing through some old email, and saw this note to me from Aitor, from when I was on vacation (Scotland). Aitor is creating a general library that will allow FreeDOS apps to extend themselves, »
Technote: EXE Packers Recently on the FreeDOS href="http://www.freedos.org/freedos/join/"> mailing list , there was a discussion that eventually lead to EXE packers for DOS. I am reproducing that part of the discussion here, as the topic seems to come »
Booting FreeDOS from logical partition I saw this posted on the mailing list, and I am reposting it here because others may have a need to install FreeDOS on a logical partition and boot from there: Chris Hodapp writes: »
Using DR-DOS FAT32 in FreeDOS Recently, a user sent me this note about adding FAT32 support to FreeDOS using the drfat32 FreeDOS kernel is adding FAT32 support directly, I thought I would make this note available as a »
FreeDOS and WinME Nehal Mistry writes with this workaround for using FreeDOS and WinME: This is not a bug for freedos, but a bug with WinME As u know u need to put the freedos partition in first 2 »
FreeDOS and MS Lan Manager Tom Wyrick wrote to us with this note about using FreeDOS as a Citrix client. Tom also reports a problem with mapping drive letters from FreeDOS when using the Microsoft LAN Manager for DOS »
FreeDOS networks with UNIX Josh asked this question about FreeDOS networking: what is the current state of networking for fdos...more on the lines of Alessio Palma provides this list of examples: DOS Network file system with *nix Machines »
FreeDOS Networking Oleg Deribas responded to a thread in the FreeDOS mailing list about networking. Here is his note on networking FreeDOS in a Windows networking: It is 'Microsoft Network Client version 3.0 for MS-DOS' and it can be »
FreeDOS and 'office' software prasad mehendale writes about other 'office' software for FreeDOS: i am using freedos6 ripcord distribution on my siemen nixdorf 486 box as a standalone os very successfully. A)as you mentioned about office software some time »
CD-ROM drivers and FreeDOS Aitor writes: I have found this: free . ... Would any of Jeremy Davis responds: And Florian Xaver also writes this about a USB CD-ROM driver for DOS: Maybe this will interesst you: There's a »
FreeDOS v. MS-DOS compatibility It's always worth reading the comments posted by Matthias Paul. Matthias has quite an extensive background with DOS, and has a close history with DR-DOS. So I immediately stopped to read this note from Matthias »
Michael Kallas writes: I was looking for means to transfer files via nullmodem from my notebook to the desktop. I found the site archives.thebbs.org/ra90c.htm where many drivers (and different protocols) can be found. Earlier I had already found Zest2.0 »
FreeDOS Networking Florian Xaver found this DOS networking information, and I am re-posting it here because it should be of interest to anyone trying to put FreeDOS on a network: Check these links for DOS connectivity stuff. http://home7.inet.tele.dk/batfiles/main/links.htm#connectivity DOS »
This is a copy of the FAQ - see http://www.dendarii.co.uk/FAQs/dos-apps.html FAQ: MS-DOS Applications for Internet Use Last-Updated: 9 June 2002 Posting-Frequency: Monthly Version: 2.3.0 URL: ftp://ftp.demon.co.uk/pub/doc/ibmpc/dos-apps.txt MS-DOS APPLICATIONS FOR INTERNET USE Compiled by Michael Bernardi This material was »
Bloodhound virus false-positives You may have noticed that if you download the boot floppy to the FreeDOS distributions, your Windows anti-virus software may think there is a virus on the FreeDOS boot floppy. In almost all cases, there really »
Information on new lbacache Eric Auer sent this email to me when I posted the previous announcement about his lbacache hard disk cache. I am reposting it here in its entirety: Eric writes: Hi, I just read your newsitem »
Win31 runs on FreeDOS! This news came in just before Christmas, 2001: Aitor writes: Many, many congratulations to EVERYBODY!!!! It still needs some things to be worked out, configuration to be Ok, now the brief details: Ripcord B7H1 + »
FreeDOS NLS Tables Aitor writes this about a remarkable similarity between the FreeDOS NLS and Microsoft's NLS for DOS. This just demonstrates that the same engineering problem is often solved by two independent observers in the same fashion: I »
2002-02-06 FreeDOS USB support The following exhange was seen recently on the FreeDOS mailing list : Kurt Zammit writes: I was surfing the net for info on USB. At the moment I've got sources for low-level I would »
XKeyb and MKeyb The following technote is by Aitor: Just in order to avoid some confussion, I'd like to send to you this excerpt from the versions.txt file at ibiblio's xkeyb section, which briefly details similarities and »
FreeDOS for Electrical Engineers Prasad Mehendale wrote to me about using FreeDOS with students in learning about microcontrollers. This is very encouraging, and I am pleased to see that Prasad has done this. Congratulations! The programs they use seem »
2002-07-14 Optimizing your computer SPEED! I would like to share what I have found in my 27 years of trying to get the most speed from my computers. 1. First define your needs. What programs do you REALLY use »
MT and FreeDOS Herwig (of the MT program) wrote with this update: Hi Jim, I've seen that you published a poor Babelfish translation of the multitasking kernel MT which I have written for DOS some time ago. To get »
Technote Details on USB for DOS (from a BIOS developer) Russell writes: I am a tremendous fan of FreeDOS, so as a USB/1394 BIOS engineer, I would like to provide you with the following information if it helps. (I »
Results of testing FreeDOS FDISK 1.1beta 2002-09-02 Robert Platt wrote in with this review of the FreeDOS FDISK 1.1beta release: Here are the results of some testing I did on Free FDISK 1.1 Beta. Generally positive: This was »
FreeDOS and embedded systems Sy Wong wrote to me asking if there are any FreeDOS developers who are interested in Application-Specific Integrated Circuit (ASIC) technology. FreeDOS is often used in embedded systems, and I'm sure we have many embedded »
2002-09-30 Running emTeX on FreeDOS The following was written by Hetteh: I made some testings. emTeX INSTALL prog proceeds in 2 steps: STEP 1. copying required files, patching emTeX BAT files, updating autoexec.bat & config.sys STEP 2. after rebooting, »
2002-10-30 USB Support in DOS Hetteh found this: www.informationweek.com/story/IWK20021003S0007 : "Fred Langa illuminates the pervasive but little-understood world of USB, explaining how to hook it up to non-USB systems and peripherals--even in DOS!" An excerpt from the »
2002-11-13 CD-ROM drivers for DOS? Andreas K. Foerster wrote: Hello, Jim Lemon wrote: I use the Oak CD-ROM driver recommended at the following page: web site . This is a good place to look for this sort of info »
2003-02-05 Saving MBR information I saw this note on the FreeDOS mailing list, and had to post it as a technote - how to save, restore, and refresh the master boot record. This is very valuable information, and may »
2003-03-27 MetaKern Eric Auer writes: Hi all, due to popular demand (?), I hereby release a new MetaKern version! http://www.coli.uni-sb.de/~eric/stuff/soft/specials/ -> (metakern.zip in the same directory is updated, too) Please read the explanations at the beginning of the source »
2003-04-07 FreeDOS GRAPHICS - progress? Eric Auer wrote to Usagi : (and I'm reposting it here, because I tend to repost things that are sent to me ... -jh) I think I can translate all your C »
2003-04-08 Using DLLs and Causeway DOS Extender Devore It is recommended that you understand and familiarize yourself with the basic operation of Windows DLLs before using them with CauseWay under DOS. You should also study the DLL »
2003-05-11 FreeDOS GRAPHICS - links Eric Auer has released a version of FreeDOS GRAPHICS, which allows Prtscr to print graphics screens. Here's Eric's announcement: The program is written in NASM assembly language and this first version only supports PostScript »
To add to FreeDOS? Steve Nicholas writes: Eric and I discussed things we felt would be nice if added to FreeDOS. I think, of everything which isn't there that's in MS-DOS, the only things that are yet to »
Downsizing some FreeDOS utils Eric Auer writes: Hi, apart from upx-ing files, I think a few of our files also just contain too many libraries. In addition, SWSUBST / JOIN / SUBST could be done in a way that »
FreeDOS POWER thoughts? Update- Eric adds: Although, the UNIDLECHECK code still is not there. It would be the idea to use it to idle the CPU even when the program does not wait for keypresses, based on some heuristics »
2003-06-02 DOS anti-virus software Eric Auer writes: Hi, I checked a few sites... http://www.antivir.de/ (Free-for-personal-use-Windows-version: www.free-av.de) http://www.bitdefender.com/ http://www.f-prot.com/ all have "free for personal use" DOS and Linux licensing policies. Bitdefender also has free PalmOS/WinCE versions. As maintaining antivirus software »
2003-07-05 USB problems Lawrence W posted this note (warning? rant?) to the FreeDOS mailing list and I thought I should re-post it as a technote: I thought I should post this as a warning to the group. I have »
2003-07-26 Warning: ASUS motherboards and FreeDOS Eric Auer writes about this warning for ASUS motherboard users: Hi, I got a complaint about a broken FreeDOS installer on a CD-ROM that seems to be shipped with ASUS P4PE motherboards: »
2003-08-01 A note on CPUs Matthias Paul wrote this email to the fd-dev list about a different topic, but as always, Matthias presents information that may be useful to other FreeDOS developers, so I thought I'd re-post his comments »
2003-08-02 Networking under FreeDOS Often, we see questions like this on the FreeDOS mailing list: "A lot of times I read about internet browsing for DOS using modem and PPP dialers, or ADSL and PPPoE. My question is how »
2003-08-24 FreeDOS and Windows 3.1? This thread comes up from time to time on the FreeDOS mailing list, so I thought I would add it as a technote: The question was: I do hope FreeDOS will run Win3.1 one »
2003-08-29 GRUB for DOS wengierwu writes: Hi! The author of GRUB for DOS has written down the following details about the bugs in FreeDOS Kernel 2030/2031: [...] Important Note: Since FreeDOS build 2030/2031 saved a wrong BIOS interrupt vector »
2003-08-29 USB support for DOS Arkady writes: The Inquirer publishes article, where noticed Matsushita's driver, which allows to work with external USB disks under DOS. Example of config.sys and autoexec.bat to access external CD-ROM: config.sys autoexec.bat usbaspi.sys and usbcd.sys »
2003-11-15A Installing FreeDOS on WinNT/2000/XP: NTFS resize hints Eric Auer writes: Hi, I think people today often have XP, and XP often defaults to allocate all the disk (except maybe a hidden FAT32 recovery partition) for itself in NTFS. »
2003-11-30A Running Windows on FreeDOS Thomas Hirsch Just want to let you know that the current kernel (as found in CVS as per 25.11.2003) is solving a long existent problem/bug. It is now possible to install windows2000 or »
2003-12-31 MS-DOS errorlevels Eric Auer points us to a page of MS-DOS errorlevels: See users.cybercity.dk/~bse26236/batutil/help/BATCHSUP.HTM#8.01 This explains the errorlevels of FIND, CHKDSK, CHOICE, DEFRAG, DELTREE, DISKCOMP, DISKCOPY, FC, FIND, FORMAT, KEYB, MSAV, REPLACE, RESTORE, SCANDISK, SETVER, XCOPY. Because »
12/15/2003 New EMM386 with 511M EMS support Michael Devore writes: Offered for anonymous FTP download at ftp.devoresoftware.com/downloads Michael Devore's changes are not copyrighted and are released to the public domain. This does not affect copyright on the rest »
12/27/2003 Revised EMM386[64] for download Michael Devore writes: Available via anonymous FTP download at ftp.devoresoftware.com/downloads Release of this revision and announcement of same has received approval by Tom Ehlert, maintainer of EMM386. not , however, to be considered »
12/11/2003 A new MODE for the new DISPLAY is ready Eric Auer writes: Hi, now that the codepage packs for the current DISPLAY version 0.10 are ready, I am happy to announce an update of my MODE version: http://www.coli.uni-sb.de/~eric/stuff/soft/specials/ »
ASUS motherboards and FreeDOS Warning: ASUS motherboards and FreeDOS! ASUS motherboards which contain FreeDOS for their CrashFreeBIOS function sometimes ship with an incomplete FreeDOS installer on the CD-ROM. Do not try to install FreeDOS with it - and be »
2004-2-5 FreeDOS UDMA disk speed and LBAcache benchmarks Eric Auer writes: Hi, I have done some harddisk speed benchmarks on my system. I found UDMA to work well (but it is incompatible to some of the DOS extenders used »
2004-02-06 PC-Config 9.33 now freeware! / more LBAcache+UDMA tests Eric Auer writes: Hi, forwarding a good hint from Uwe Sieber (UMBPCI guy): http://www.holin.de/ has PC-Config analyzing tool 9.33 now as FREEWARE, in English and German versions. I think it »
2004-02-15 Multimedia under FreeDOS Florian X wrote: My goal was, to view videos and listen to MP3s, CDs and OGGs under DOS. (Seems to work.) I am using 2 Programs: -- MPXPLAY - for listening to CDs, MP3s, AAC »
2004-03-06 ClamAV patch / DOS binary Eric Auer writes: Hi, Joergen Ibsen (of IbsenSoftware.com / aPack...) was kind and smart enough to write a patch to make ClamAV compile in DJGPP and to do the compiling on his LFN »
2004-03-10 Technical information about hard disks Eric Auer uncovered this store of information about hard disks. Useful for anyone working on a DOS program require low-level access to the hard drive. Hi, a tester reports that FreeDOS FORMAT 0.91o »
Rebooting from user-space 2004-03-13 On the mailing list, we had a discussion about "safe" rebooting of a PC through the BIOS. First: True that once long time ago it was discussed that the rebooting method of jumping to certain »
Accessing the Internet from FreeDOS 2004-05-31 Eric Auer posted a note to the freedos-devel mailing list about accessing the Internet from FreeDOS. I thought I'd repost it here: I am writing this mail in DOS: How to do this: »
Ensoniq 1370 / SB PCI64 soundcard Originally posted 17 Jun 2004, by Eric Auer: Hi, for your Ensoniq 1370 / SB PCI64 soundcard, you might try those drivers: http://www.fujitsu-siemens.co.uk/rl/servicesupport/techsupport/boards/Soundcards/PCI64-Q3D/PCI64(238Q).html , http://www.nickles.de/c/a/archiv1-78531.htm http://www.spmicro.com/mp3sidekick/ensoniq.html Normally, you only have to »
FreeDOS bugs for 1.0 2004-09-11 bootablecd Here is a list of things which should be done before you bring out the version 1.0. I know I should mail this in Bugzilla, but a) I hate Bugzilla because it »
ADSL connection to web - DOS Found on http://www.undercoverdesign.com/dosghost/forum/mesg/194.htm Posted by Svend Broholm ( on October 04, 2003 at 12:56:35 GMT-620: In Reply to: Re: ADSL conecction to web - It's possible on DOS posted by Charles Angelich »
FreeDOS and Linux dual boot floppy 9/27/2004 This post on freedos-devel seemed so interesting, I thought I'd share it here. If you have a need to dual-boot FreeDOS and Linux, this is a good solution. (If you run Linux, »
FreeDOS Beta9 errata 9/29/2004 Eric Auer writes: Hi, I started collecting some errata / comments about the FreeDOS beta 9 ISO image and the readme.txt file in the download directory. Unless our fileserver gets confused again, you can find »
FreeCom and 4DOS descript.ion files Jeremy Davis writes: I actually had a few free minutes today so I implemented the requested feature for bug#1889, have DIR command display descriptions from 4DOS's DESCRIPT.ION files if available. Get from usual place, »
Installing FreeDOS Worst Case Scenario 6/23/2005 Eric Twose writes with this advice: If you have a boot disk and a FreeDOS installation CD ** , but: can't access the CD on the local machine, get XMSSwap "no memdisk found" »
Dual-boot "Real" DOS on Windows XP 2005-07-24 Mark Bailey had documented a way to dual-boot FreeDOS with Windows XP, without having to re-install Windows. You can install FreeDOS on a new computer and have it dual-boot with Windows XP »
Installing Windows98 from FreeDOS 2007-05-11 Every so often, someone will ask about using FreeDOS to install Windows95 or Windows98. So we should have a technote on that. Bernd provides this advice: SETUP /NM /IS ( N o M achine »
freeware NetRun, NetSend & NetPic utilities 2007-05-14 MyWorkAccount writes: Hi all! I'm found these utilities: Description on this ( http://www.pa-spaug.org/News97/1997archive.htm ) by Jim Tucker: jtucker@byron.apana.org.au has written three DOS programs which enable binary files to be emailed in ASCII »
PXE booting FreeDOS 2007-08-27 A user emailed me to ask (in short) how to boot FreeDOS using PXE? The target PC only has a network card and memory ... no hard drive, no floppy, no USB, no CD-ROM. Has »
(e)speak for DOS 2007-08-27 Dietmar Segbert writes with this tip: Hello, I have compiled the espeak tts system with djgpp. thanks to Eric and Jonathan (author of espeak). To compile espeak you must do the following: Download the latest »
This has been moved to the FreeDOS Wiki ( Fdupdate ) »
This has been moved to the FreeDOS Wiki ( Package ) »
How to use NLS / COUNTRY settings 2008-03-09 This is taken from a 2004-06-04 posting in the now closed bugzilla item 1236, as the posting basically solves the "bug"... Note that we do COUNTRY.SYS support now, but »
2008-07-10 Arachne HTML support This document describes the HTML support found in the Arachne WWW browser HTML tags Tag Same as Options A removable, href, name ARACHNE msg, raw, nocache, target, print AREA B EM, STRONG BASE href »
Cisco WiFi support for DOS 2008-07-22 Roberto wrote: i've found this intersting info regarding drivers, hardware and more for running wi fi apps on plain DOS: www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note09186a00801beda4.shtml www.cisco.com/en/US/docs/wireless/wlan_adapter/350_cb20a/user/ms-dos/configuration/guide/dosinst.pdf www.cisco.com/cgi-bin/tablebuild.pl/aironet-utils-dos DOS drivers for Cisco Aironet 350 series PCMCIA, PCI or »
This page has been removed. The original is at http://www.unet.univie.ac.at/~a0503736/php/drdoswiki/index.php?n=Main.Compatibility »
2008-09-22 Sound programming in DOS Michael Reichenbach wrote: I've created based on the original contents in drdos.org wiki, the discussions here on the mailing list and some of my own researches an article about sound programming DOS. It's purpose »