FreeDOS to Oberon System 3

By R. S. Doiel, 2019-07-28

UPDATE: (2021-02-26, RSD) Under VirtualBox 6.1 these instructions still fail. My hope is to revise these instructions when I get it all sorted out.

Many links such as the ftp site at ETH Oberon are no more. I’ve updated this page to point at Wayback machine or included content in here where I cannot find it else where.

UPDATE: (2021-02-19, RSD) Under VirtualBox 6.1 these instructions fail. For VirtualBox I’ve used FreeDOS 1.3rc3 Live CD installing the “Plain DOS” without problems.

UPDATE: (2021-03-16, RSD) After reviewing my post, correcting some mistakes I finally was able to get FreeDOS up and running on VirtualBox 6.1. This allows NativeOberon 2.3.6 to be brought up by booting the “oberon0.dsk” virtual floppy and following the instructions included. You need to know how to use the Oberon mouse and the way commands work in Oberon.

What follows are notes on getting a FreeDOS 1.21 and then Native Oberon2 running under VirtualBox 6.0. You might wonder why these two are together. While it was easy to run the Native Oberon installation process that process assumes you have a properly partitioned hard disk and VirtualBox seems to skip that process. I found taking advantage of FreeDOS simplified things for me.

My goal was running Oberon System 3, but setting up a Virtual Box with FreeDOS 1.2 gave me a virtual machine that functions like a 1999 era PC. From there all the steps in the Oberon instructions just worked.

Creating FreeDOS 1.2 Virtual Box

I’ve been doing a bit if computer history reading and decided to bring up some older systems as a means to understand where things were. The first computers I had access to were 8080, 8086 machines running MS DOS based. My first computer programming language was Turbo Pascal. Feeling a bit nostalgic I thought it would be interesting to use it again and see what I remembered from the days of old. While PC and MS DOS no longer exist as commercial productions an wonderful group of Open Source hackers have brought new life into DOS with FreeDOS 1.23. You’ll find many of your old familiar commands but also some nice improvements. You can even run it under VirtualBox which is what I proceeded to do.

VirtualBox 6.0 setup

The FreeDOS website includes a CD ROM image that you can use to install it. There are couple small hitches though to get it working under VirtualBox. First go to the download page and download the CDROM “standard” installer”.

While that is downloading you can setup your VirtualBox machine. First to remember is DOS compared to today’s operating systems is frugal in its hardware requirements. As a result I picked very modest settings for my virtual machine.

  1. Launch VirtualBox
  2. From the menu, pick Machine then pick new
  3. Name your machine (e.g. “FreeDOS 1.2”), select the type: “Other” and Operating system of “DOS”
  4. Set memory size as you like, I just accepted the default 32MB
  5. Hard disk, pick “Create a virtual hard disc now”
  6. Hard disk file type, pick “VHD (Virtual Hard Disk)”
  7. Storage on physical hard disk, I picked Dynamically allocated both either is fine
  8. File location and size, I accepted the default location and size
  9. Before starting my FreeDOS box I made a couple of changes using “settings” menu icon
    1. Display, I picked bumped memory up to 128M and picked VBoxSVGA with 33D acceleration (for games)
    2. Storage, I added a second floppy drive (empty)
    3. Network, I picked attached to NAT
  10. When looking at my virtual machine’s detail page I clicked on the Optical drive (empty), click “choose disc image” and pointed at the downloaded installed CD
  11. Click Start.
  12. At “Welcome to FreeDOS 1.2” blue screen, hit TAB key
  13. You will see a line that begins with a boot instruction. Add a space than add the word “raw” (without quotes) press enter
  14. Follow the install instructions, when you get to “Drive C: does not appear to be partitioned” dialog, pick “Yes - Partition drive C:”
  15. On the next screen pick “Yes - Please reboot now”
  16. When at the “Welcome to FreeDOS 1.2” screen hit TAB again
  17. Once again add a space and type “raw” to the command then press enter
  18. Pick “Yes - continue with the installation”
  19. Pick “Yes - Please erase and format drive C:”
  20. At this point its a normal FreeDOS install
  21. When the install is done and reboots “eject” the virtual CD form the “Optical Drive” in the VirtualBox panel, then choose “boot from system disk”,you now should have a working FreeDOS on VirtualBox

Native Oberon System 3 on Virtual Box

Native Oberon can be found at There is a related ftp site4 where you can download the necessary files for the stand alone version.

Here’s the steps I used in my Mac to download Native Oberon and into a file on my desktop called “NativeOberon-Standalone”. Open the macOS Terminal application. I assume you’ve got a Unix command called wget already installed5.

NOTE: The ETH ftp server is no more. I’ve included Web Archive links and links to my own copies of the files needed to install Native Oberon 2.3.6 in the paragraphs that follow. RSD, 2021-03-16

    mkdir -p Desktop/NativeOberon-Standalone
    cd Desktop/NativeOberon-Standalone

Clone your FreeDOS Box first. You’ll want to do a “Full Clone”. You’ll also want to “remove” any optical disks or floppies. You do that from the virtual boxes’ detail page and clicking on the drive and picking the “Remove disk from virtual drive” in the popup menu.

At this point we have a a virtual machine that is very similar to an 1999 era PC installed with MS DOS. Native Oberon Normally you’d install Native Oberon via 1.44MB floppy disks. We can simulate that with our Virtual machine. In the folder of you downloaded there is disc called “oberon0.dsk”. That can go in our first floppy drive. But how to we get the rest of the files onto a virtual floppies? This wasn’t obvious to me at first.

The Oberon install disks were organized as follows

Oberon-0 oberon0.dsk 0
Gadgets gadgets.arc 1.4 2.9 1
Documentation docu.arc 1.3 2.5 2
Applications apps.arc 1.3 2.8 3
Tutorials tutorial.arc 0.3 0.8 4
Pr3Fonts pr3fonts.arc 0.3 0.6 4
Pr6Fonts pr6fonts.arc 0.5 1.8 4
Source1 source1.arc 0.9 2.5 5
Source2 source2.arc 1.2 3.5 6
Source3 source3.arc 0.6 1.7 7

It turns out you can create 1.44MB Fat16 disc images from the Virtual Box 6.0 floppy drive link. When you click on the floppy drive in the details page you have a choice that includes “create a new floppy disc”. Select this, find the disc a filename like “disk1”. Click on the virtual floppy disk in the Virtual Box and “remove” the disc then create disk2, disk3, etc. In each the empty disc image files places the files from the table above. These image files can then be opened on your host operating system and files copied to them. It’s a tedious process but this gives you something the Oberon System can read and install from. Originally I just put all the files into an ISO CD ROM image but I could not figure out how to mount that from this version of Oberon. Now when you start up your Oberon V3 virtual machine you can install the rest of the software like Gadgets.

  1. FreeDOS is an Open Source implementation of PC/MS DOC↩︎

  2. Native Oberon is a 1990’s version of Oberon System running on i386↩︎

  3. Download FreeDOS from↩︎

  4. Download Native Oberon Stand Alone from↩︎

  5. wget is easily installed with HomeBrew or Mac Ports↩︎