This year we have a total of seven competitions, please note that the music and graphics compos have been updated to focus on lower end platforms. Eventual highres graphics and streaming music entries are moved to the new Wild category. Due to the compos being streamed on Twitch, please be advised not to use commercial music or nudity in your productions. There's a risk the stream will be banned in such a case (see Revision 2021).
Demos that work on the provided compo hardware will be run live on our machines while other Atari platforms will need a video/audio recording to be submitted.
We will display full specifications of the hardware requirements as well as file size/resolution before each entry is shown.

Remote entries
You can send us remote entries via e-mail (please add SOMMARHACK to the subject so we don't miss it by mistake). Please tell us in your mail which machine and compo the production is aimed for. You can also add a short note for the compo slide. Don't forget to make a video or audio recording available if the production is for a system we don't have at hand.
Send entries to:
Thanks in advance for your participation!

For the most recent timetable with deadlines, please refer to the main page.

Compo hardware
These are the machines we will provide for the competitions; if your contribution is for another Atari machine, please submit a recording that we can play.
Atari 8-bit
  • Atari 65XE
  • 576 kB RAM
  • SD2SIO
Atari ST/STe
  • Atari STe machine
  • TOS v1.62 (or if you require, 2.06)
  • 4MB ST-RAM
  • 8 MHz 68000
  • Floppydisk (Gotek HxC)
  • UltraSatan/CosmoSEX SD harddrive (HDdriver)
Atari Falcon 030
  • TOS v4.04
  • 14 MB ST-RAM
  • 68030/68882 at 16 MHz
  • SSD IDE harddrive (HDdriver)
  • VGA or RGB
Atari Falcon 060
  • CT60-TOS v1.05
  • 14 MB ST-RAM
  • 256 MB TT-RAM
  • 68060 with FPU at 66 MHz
  • SSD IDE harddrive (HDdriver)
  • VGA or RGB

THEMED COMPO #01 - Monochrome demo

What, the same themed compo as last year?
Yes, almost! We received very good feedback from last years monochrome compo. Several people asking for a return but with less restrictions. So let's make it happen! Now we can see what the monochrome mode has to offer, for real.

  • Atari ST or Atari STe
  • Monochrome hi-res 640x400 mode
  • 4MB RAM
  • Floppydisk or harddrive
  • More than one entry per participant/crew allowed
Tip: Don't rely on tricks that only work on SM124/144 screens. It won't show well on the projector (or stream).


We've tried many ST graphics modes for our previous photo competitions; ST-HIGH, ST-MED, ST-LOW and last year the Spectrum 512.

We're sort of running out of ST screenmodes and will move on to the Atari TT-MEDIUM resolution, with a greyscale limitation.

  • Pure photographs only, no manual pixelling or retouching
  • 640*480 pixels
  • 16 colour greyscale (black to white linear scale)
  • Deliver in GIF or 8-bit PNG format
  • Max three entries per person
The photos will be shown on a real Atari with the Apex GIF viewer.

Check out an example 640*480 photo with TT-greyscale palette.

Check out a guide how to use Photoshop to make a TT-MED greyscale photo



REGULAR COMPO #01 - Demo/intro

This is a combined competition and we will make sure that all hardware specifications as well as size of the demo is shown before it runs. You can enter any kind of Atari demo here, no limits!
  • Any Atari platform allowed, if your demo or intro is for an Atari platform not available at the party, please supply a video along with the native executable
  • Filesize, system and memory demands are open, but will be disclosed in detail before and after the entry is shown
  • Several entries per person or crew is allowed

REGULAR COMPO #02 - 256-byte intro

Again a combined compo. For Atari ST, STe and Falcon entries we offer an MT-32 MIDI-synth for audio output if you wish to take advantage of that.
  • Any Atari machine, specifications will be disclosed
  • For TOS machines, 256 bytes plus 32 bytes header.
    If you want to show off, keep it under 256 bytes with header! The exact size will be disclosed
  • If the intro requires a certain resolution to be set before running, instruct so in the submit e-mail
  • Don't forget to mention if the intro requires MT-32 MIDI synth
  • Several entries per person or crew is allowed
The intros will be run on our compo machines (see left column). If your entry is for another Atari system, please provide a video along the executable!

REGULAR COMPO #03 - Lowres graphics

We update the graphics compo a bit for 2023. The resolution is limited to what the ST can display with overscan. High-res images are welcome in the Wild compo instead.
  • Max resolution is 416*274
  • If you have a custom graphics format, please provide an Atari executable file for display.
  • The machine, resolution, size and number of colours will be disclosed in the compo slide
  • More than one entry allowed

REGULAR COMPO #04 - 32k music

As with the graphics compo, we have changed it a bit for 2023 by limiting the size. Larger music such as mp3 or wave are welcome in the Wild competition.

This compo is suitable for chipmusic, small modules and softsynths. We allow any format that is playable on an Atari. If the music is for an Atari machine that we don't have at the party, please send a recording along with the native version of the music.
  • Custom formats are allowed and encouraged. You need to provide an executable.
  • More than one entry allowed
Tip: If you're having problem with too large SNDH file, ICE pack the file to reduce it's size or create an executable and compress it with with something like UPX for good ratio.


No compo that fits your entry? This is where it can be submitted. Animations, streamed music, analogue graphics, game or anything that you think will fit a demo party.
  • You have to submit a picture, video or audio recording, please use commonly available codecs such as Flac, Mp3, Ogg Vorbis, H.264
  • More than one entry allowed
Please don't attach giant files to the submit e-mail, instead link to the file (Dropbox or whatever you can provide). If all fails, contact us and we'll try to arrange some sort of way to transfer the file.