[Oberon] RISC emulator

Jörg Straube joerg.straube at iaeth.ch
Mon Mar 17 13:01:28 CET 2014

Hi all

Introducing German letters is more complicated than I originally thought.
- You could do a first hack by just allowing one byte characters >127.
  As there exist different ASCII extensions for characters >127, eg. ISO-8859-1, code page 437 or Mac OS Roman, you have to chose which code page you want to implement in ProjectOberon.
      ISO-8859-1    code page 437  Mac OS Roman
  ä        E4                    84                      8A
  ö        F6                    94                      9A
  ü        FC                    81                      9F
  Benefit: even umlauts are one byte and fit in a standard CHAR.
  Disadvantage: you have to chose a certain code page and file transfer to other OS have to take care of the chosen code page. I would chose ISO-8859-1.

- A more general approach to support international languages would be to use Unicode and take internally UTF-8 as encoding.
  ä        C3 A4
  ö        C3 B6
  ü        C3 BC
  Benefit: almost all newer OS base on Unicode and UTF-8, Unicode is ready for ALL international languages not only German.
  Disadvantage: Implementation is more complex. You have to convert strings into UTF8 and back. Umlauts do not fit into one CHAR anymore.

For the sake of simplicity, Wirth restricted this little project to ASCII only. The extensions mentioned above can be seen as an exercise :-)


Am 17.03.2014 um 09:31 schrieb Jörg Straube <joerg.straube at iaeth.ch>:

> Hi
> The German characters (ASCII character codes above 7F) do not only impact the keyboard driver (Input.Mod) but also the fonts (Fonts.Mod) and Files.Mod if you want to allow filenames with German letters. The current Fonts.Mod used in the RISC implementation restricts the character pattern to <80H.
> Br, Jörg
>> Am 17.03.2014 um 00:04 schrieb Peter De Wachter <pdewacht at gmail.com>:
>>> On 16-03-14 22:22, Peter Matthias wrote:
>>> Hi Peter,
>>> thanks for the emulator. It made me get interested in Oberon-risc.
>>> It compiles and runs well on Ubuntu/X64, however, German keyboard layout 
>>> is not recognized.
>>> Two questions:
>>> - How do I copy files to/from the disk image?
>>> - What are *.smb files?
>> I don't have a way yet to transfer files to Oberon. The system supports
>> file transfer over RS-232 or wireless but those interfaces aren't
>> emulated yet. I think it might be possible to mount the disk image with
>> one of the "big" Oberon implementations and transfer files that way, but
>> I haven't tried that yet.
>> To get a German keyboard layout, you'll have to edit the keymap table in
>> Input.Mod. The emulator only deals with scancodes, translating those to
>> characters is Oberon's job.
>> --
>> Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systems
>> https://lists.inf.ethz.ch/mailman/listinfo/oberon

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