Various experiments with the functionality, the module structure and the boot process of Oberon 2013
Modula-2 Shell Perl
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.
Documentation first commit Aug 17, 2018
Sources first commit Aug 17, 2018
.gitignore first commit Aug 17, 2018 first commit Aug 17, 2018
dos2oberon first commit Aug 17, 2018
oberon2dos first commit Aug 17, 2018

The Experimental Oberon operating system

Experimental Oberon is a revision of the Original Oberon operating system and compiler (, containing a number of enhancements, including

  • Continuous fractional line scrolling with variable line spaces
  • Enhanced viewer operations
  • Multiple logical displays ("virtual displays")
  • Safe module unloading
  • System building and maintenance tools
  • An enhanced Oberon-07 compiler with various new features, including
    • Numeric case statement
    • Exporting and importing of string constants
    • No access to intermediate objects within nested scopes
    • Forward references and forward declarations of procedures
    • Generic heap allocation procedure NEW(p, size)
    • Module contexts

Documentation: The-Experimental-Oberon-System.pdf

Additional background material can be found in the Documentation directory.

Note: The latest version of Experimental Oberon is always at All other repositories at are just a series of small experiments that people are free to use, but without ANY guarantee that they will be kept current or in sync with Experimental Oberon.

Instructions for converting an existing Original Oberon system to Experimental Oberon

NOTE: If you run Oberon in an emulator (e.g.,, you can simply backup your existing S3RISCinstall directory, download the compressed archive S3RISCinstall.tar.gz from this repository (containing Experimental Oberon) to your emulator directory, run the command tar xvzf S3RISCinstall.tar.gz in that directory and then restart the emulator, instead of going through the instructions outlined below.

PREREQUISITES: A working Original Oberon 2013 operating system and compiler, current as of July 23, 2018 or later (see for the change log of the Original Oberon 2013 operating system and the Oberon compiler). If you run an older version of Original Oberon 2013, please upgrade to the latest version first.

STEP 1: Build a slightly modified Oberon compiler on your Original Oberon system

Edit the file ORG.Mod on your Original system and set the following constants to the indicated new values:

 CONST ...
   maxCode = 12000; maxStrx = 3200; ...

Then recompile your Original Oberon compiler (and unload the old one):

 ORP.Compile ORS.Mod/s ORB.Mod/s ~
 ORP.Compile ORG.Mod/s ORP.Mod/s ~
 System.Free ORP ORG ORB ORS ~

This step is (unfortunately) necessary since the original Oberon-07 compiler has a tick too restrictive constants. To compile Experimental Oberon, one needs slightly more space (in the compiler) for both code and string constants.

STEP 2: Download and import the Experimental Oberon files to your Original Oberon system

Download all files from the Sources directory of this repository. Convert the source files to Oberon format (Oberon uses CR as line endings) using the command dos2oberon, also available in this repository (example shown for Linux or MacOS):

 for x in *.Mod *.Tool ; do ./dos2oberon $x $x ; done

Import the files to your Oberon system. If you use an emulator, click on the PCLink1.Run link in the System.Tool viewer, copy the files to the emulator directory, and execute the following command on the command shell of your host system:

 cd oberon-risc-emu
 for x in *.Mod *.Tool *.Scn.Fnt ; do ./ $x ; sleep 0.5 ; done

Open the Experimental Oberon version of the System.Tool viewer in the system track of your Original Oberon system, so that you can directly activate the compilations needed to build Experimental Oberon:

 System.Open System.Tool

If you just follow the compilation sequence shown in System.Tool, you should be done with the remaining steps 3-5 in a few seconds!

STEP 3: Build a cross-development toolchain by compiling the "new" compiler and boot linker/loader on the "old" system

 ORP.Compile ORS.Mod/s ORB.Mod/s ~
 ORP.Compile ORG.Mod/s ORP.Mod/s ~
 ORP.Compile Boot.Mod/s ~
 System.Free ORP ORG ORB ORS Boot ~

STEP 4: Use the cross-development toolchain on your Original Oberon system to build Experimental Oberon

Compile the inner core of Experimental Oberon and load it onto the boot area of the local disk:

 ORP.Compile Kernel.Mod FileDir.Mod Files.Mod Modules.Mod ~    # modules for the "regular" boot file for Experimental Oberon
 Boot.Link Modules ~                                           # generate a pre-linked binary file of the "regular" boot file (Modules.bin)
 Boot.Load Modules.bin ~                                       # load the "regular" boot file onto the boot area of the local disk

This step is possible, because module Boot is written such that it can be executed on both the Original Oberon 2013 and the Experimental Oberon system. It produces output using the Experimental Oberon module and object file format.

Compile the remaining modules of Experimental Oberon:

 ORP.Compile Input.Mod Display.Mod/s Viewers.Mod/s ~
 ORP.Compile Fonts.Mod/s Texts.Mod/s Oberon.Mod/s ~
 ORP.Compile MenuViewers.Mod/s TextFrames.Mod/s ~
 ORP.Compile System.Mod/s Edit.Mod/s Tools.Mod/s ~

Re-compile the Oberon compiler itself before (!) restarting the system:

ORP.Compile ORS.Mod/s ORB.Mod/s ORG.Mod/s ORP.Mod/s ORTool.Mod/s Boot.Mod/s ~

The last step is necessary because Experimental Oberon uses a different Oberon object file format (the currently loaded Experimental Oberon compiler runs under Original Oberon, but wouldn't be able to execute under Experimental Oberon).

STEP 5: Restart the Oberon system

You are now running Experimental Oberon. Re-compile any other modules that you may have on your system.