These are bootable DOS images that can be written to diskette and then booted
on a real system, or booted under DosBox with my DBDOS tool.

To the best of my knowlege these have all been released "free" - if you hold
copyright to any of these and do not want it included here, please contact me
and I will remove it!


These are DOS versions that I use to "test stuff".
They are not the "latest and greatest" and have been kept small(ish) to allow
room to "add stuff" as needed. They are missing DOS files/utilities I don't use
in my testing.
 (let me know if I've omitted something you'd really like to see included)

    PCDOS090    :   IBM dev. pre-release of DOS 1.00            *1
    PCDOS100    :   IBM PC-DOS 1.00                             *1
    PCDOS110    :   IBM PC-DOS 1.10                             *1
    PCDOS210    :   IBM PC-DOS 2.10                             *2
    PCDOS300    :   IBM PC-DOS 3.00
    PCDOS330    :   IBM PC-DOS 3.30                             *3
    PCDOS71     :   IBM PC-DOS 7.1
    MSDOS112    :   Microsoft MS-DOS 1.12                       *1
    MSDOS211    :   Microsoft MS-DOS 2.11                       *2
    MSDOS331    :   Microsoft MS-DOS 3.31                       *3
    MSDOS400    :   Microsoft MS-DOS 4.00
    MSDOS500    :   Microsoft MS-DOS 5.00
    MSDOS622    :   Microsoft MS-DOS 6.22
    FREEDOS     :   FreeDos 0.84
    CALDERA     :   Caldera OpenDOS 7.01                        *4
    PTSDOS      :   Paragon Technology Systems PTS-DOS 6.51     *5

All but *1 mount a RamDisk for "working space", and include:
    UNZIP.EXE   :   Extrac files from .ZIP
    ZDIR.COM    :   Show .ZIP content like DIR
    ZEX.COM     :   Zip EXtract (menu select)                   *6
    DOS.ZIP     :   Some common DOS tools/utilities
    DDS.ZIP     :   Some of my own tools/utilities              *6
    PKT.ZIP     :   A LOT of network "packet drivers"           *6

*1  These earliest DOS versions, won't run much newer software and have
    "weird" SS/160k disk formats that DosBox/FDI can't deal with - see the
    *2 note about alt'B' - The only way I've been able to get software
    on/off these is to make a 1.xx 160k B:, boot MS-DOS4 (Can understand
    them, and has a good working RamDisk) with B: mounted - now you can
    copy stuff on/off that B: drive, then reboot DOS1.xx and access it!
    -- some of the early IBM DOS require the PC-ROM for BASIC

*2  Early DOSs don't support 3.5HD diskettes and the images were nearly
    "full" - The only RamDisk I've gotten to work is RAMD, which occupies
    conventioanl memory - RAMD.SYS I provide is 128k. You can make a new one
    with: MKRAMD <size>
    Another way to get "working space" in DBDOS is create/mount 'B' or
    'C' drive 
    ... but... the FAT disk image format has changed enough that
    neither DosBox "IMGMAKE" nor my own "FDI" creates images they "like".
        DBDOS alt'B' (Create B:) accepts these "special" sizes:
            1 = make a 1.xx compatible 160k image
            2 = make a 2.xx compatible 360k image

*3  Version 3.x DOSs supply VDISK for a RamDrive.
    It's not clear how much conventional memory this is taking...

*4  FORMAT reports wrong DOS version (original Caldera disk) which makes it
    tricky to create other instances.

*5  This appears to be of Russian origin.

*6  Due to space/compatibility:
    ZEX.COM may be missing, use: unzip A:zipfile file...
    PKT.ZIP may be missing, NE2000.COM will be included in DDS.ZIP

NOTE:   If you have previously booted DOS with this tool, it will offer
        the selection: {templocation}\A
        as the first boot selection, allowing you to easily reboot to
        that same DOS instance (you just used)!

You may be interested in my DBDOS, a tool to boot DOS images (like these)
under DosBox on a PC. If not, you may at least want some of these files which
in includes:
    FDI.COM         : DOS: Create/Manipulate Floppy Disk Images
    XDISK.COM       : DOS: Read write Disks<>Images
    DSKWRITE.EXE    : Windows: Write Images->Disks
    DDLINK.COM/.TXT : DOS: Easily move files between DOS systems
    EDT.TXT         : Docs for my EDT editor    >Not included in DBDOS, but are
    PKTDRV.TXT      :  "" net packet drivers    >in many of my DOSBOOT .IMGs

To easily put files on/off booted DOS, I suggest using my own DDLINK.COM
This works under Dos[Box] with packet[NE2000] driver (see my DosBox edition)
- You can extract these from DDS.ZIP and PKT.ZIP archives in most of .IMGs

Dave Dunfield   -   https://dunfield.themindfactory.com

=================================== MS-DOS ==================================
In 2024, Microsoft release some older versions of MS-DOS (with source code)
under the MIT licence (see below)

I believe this would also include various OEM versions as these consist of a
simple text change. This would include: Early IBM, Compaq etc.

 ** I have not found "official" release statements for >4.0, however people I
 know assure me they were available from Microsoft FTP before it was shutdown
 - and their presense on many "archive" sites support this!
=================================== PC-DOS ==================================
A noted above, early of PC-DOS are covered Microsofts release, however IBM
did a lot of their own development in later versions.

In 2008, IBM released "Server guide scripting toolkit", which anyone could
download from their website free of charge, the "anyos_anycpu" version
includes a full copy of IBM PCDOS 7.1

You can get the original .ZIP at:
 https://www.ibm.com/support/pages/ibm-serverguide-scripting-toolkit-dos-edition-version-1307
=================================   Caldera   ===============================
Caldera grants you a non-exclusive license to use the Software in 
source or binary form free of charge if (a) you are a student, 
faculty member or staff member of an educational institution 
(K-12, junior college, college or library), a staff member of 
a religious organization, or an employee of an  organization which 
meets Caldera's criteria for a charitable  non-profit organization; 
or (b) your use of the Software is for the purpose of evaluating 
whether to purchase an ongoing license to the Software.  The evaluation 
period for use by or on behalf of a commercial entity is limited 
to 90 days; evaluation use by others is not subject to this 90 day 
limit but is still limited to a reasonable period.  Government 
agencies (other than public libraries) are not considered educational, 
religious, or charitable non-profit organizations for purposes of this 
Agreement. If you are using the Software free of charge, you are not 
entitled to support or telephone assistance.   If you fit within the 
description of a non-commercial use license, you may use the Software 
in the manner described in Parts III and  IV below under "Scope of Grant."
=================================   PTS-DOS   ===============================
I'm pretty sure the copy I have is a free "evaluation" version obtained by a
Russian collegue who has "gone home to visit" - I can't really find mention
of this on the CD --- but a lot of the material is in Russian!
================================= MIT License ===============================
MIT License

Copyright (c) Microsoft Corporation.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

