Welcome to the WUDSN ursel home page

WUDSN ursel - or short WUDSN - is a demo group founded in 1991. There is an explanation why the group and the site are named like that, but that's a different story you can find in the FAQ. For the time being it should be sufficient for you to know that I, Peter Dell aka JAC! am one of the members ever since. I have created this web site to offer my tools and productions and to share the fun I have had for more than 20 years now with my Atari-8 bit computer and other classic computers. To learn more about me and what I'm doing, check out this personal interview that I gave for ANTIC - the Atari 8-bit podcast.

WUDSN IDE update 1.7.1 released

The aim of this release was to gain long term stability and include pending fixes. It contains a lot of internal cleanups that you cannot set at the surface. The following visible changes are relevant for the users.

Java and Eclipse

  • After 7 years of successfully maintaining compatibility with Java 1.6/1.7, all Eclipse versions and the 32-bit architectures an era ends. Support by fixes in Java and Eclipse is only available for Java 1.8 and Eclipse 4.10 and later and both do not support 32-bit development environments anymore. Understandable in a time where every mobile phone has an 8-core 64-bit architecture. Therefore WUDSN IDE 1.7.1 requires Java 1.8, Eclipse 2019-06 (4.12), and a 64-bit operating system as a minimum.
  • The 1.7.1 is intentionally a minor version update, so there are no major feature changes and people who cannot migrate to the new environment can, of course, download the older version from the Releases page.


  • Source code editor added with the first version of syntax highlighting for Pascal Source Files (".pas")  that can be used with Mad Pascal.
  • Since building with MapPascal is a multi-step process, an example script file for compiling is included in the "Atari800/Pascal" folder of the zero installation download.

Hex Editor

  • Support for parsing the structure of files in Interchange File Format ("IFF") added.

Sound Editor

  •  POKEY emulation updated to ASAP 4.0.0 for compatibility and more accurate replay.


  • Online help now works again thanks to the update to Java 1.8 and the newer Eclipse version.
  • Atari TrueType fonts by Mark Schmelzenbach updated to version 1.2, which fixes the look of the capital "J".
  • If the "Skip All Breakpoints" option is active, breakpoints are now correctly skipped.
  • Copyright, features, and GPL to updated to 2020.
  • All links to the WUDSN site updated from "http://" to https://"

Request for Help

It's 11 years now since I started with the plugin. Some major things have changed in Eclipse and I'd need some help in replacing the deprecated action/actionSets extension point. So if there is anybody reading this who has experience with PDE development in the recent Eclipse builds, please contact me.

Farewell Ultrasyd

My all-time favorite chiptune musician Sydney unexpectedly died at the age of 39. I cannot believe this. I had the luck to meet him several times in person in my life at SillyVenture and Revision. I was blown away by his music, his motivation, and his kindness. Some of the best moments in my life were supported by him and his music. Another incredibly sad day in the year 2020. All I can say is thank you Sydney.

Priceless Youtube Spam

I typically ignore spam and remove it, but this one is so incredibly silly that I have to preseve it here. Really priceless. 

Atari Action! and Atari Action! Editor update released

I had received some requests for improvements to the standalone Action! editor. So I have decided to finally make it an integral part of the Action! project. Here's what has changed:

  • The Action! program is now called "ACTION.COM" in all disk versions.
  • The Action! editor is now included as "ACTIONED.COM" in all disk versions.
  • The Action! editor now has a build date, just like Action! itself.
  • The Action! editor documentation is now included as "ACTION.TXT" in all disk versions.
  • Disk version for DOS XL added.
  • Passing command line parameters to the Action! editor now also works in DOS XL.
  • Incorrect status text output has been fixed in the Action! editor.
    There had been some places in the source where ASCII/ and ATASCII was mixed up.
  • The README.TXT file on the disks now has correct EOL characters.

Feedback, especially regarding the documentation and editor are welcome!

Atari Action! Editor build version. Atari Action! Editor documentation.