Sommarhack compos
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 Wild category.

Themed competitions
  1. Zero Bitplane demo
  2. Photo (ST-MED Fullscreen dual interlace)
Regular competitions
  1. Demo/intro
  2. 256-byte intro
  3. Lowres graphics
  4. 32k music
  5. Wild
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 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 use the below example as base.

Playtime (for looping music/demos):
Slide note:
Link to video or audio recording:
Don't forget to make a video or audio recording available if the production is for a system we don't have at hand, don't attach videos to the e-mail, rather give a link (Google Drive, Dropbox whatever).
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

1. Zero Bitplane Demo

This one might need a bit of thought! Make a demo with no bitmap graphics, screen memory should be blank from any data.

  • Atari ST (no STe, no Mega ST, no blitter)
  • Colour monitor
  • 1MB RAM
  • No bitmap data on screen at all, blank screen buffer
  • Floppydisk or harddrive
  • More than one entry per participant/crew allowed
For ideas check out these demos:

2. Photo in ST-MED fullscreen with dual screen interlace

Ok, we're traversing further into the land of obscure screen modes. This particular one was made up a bunch of years ago when Percy/Light coded his Imenhance conversion tool.

The screen mode is fullscreen, medium resolution. Then add dual-screen interlace into the mix and you get something like a 832*273 image with 5-6 colours. The conversion to this complex and strange format is easy with an online-tool, so don't be scared.

  • Pure photographs only, no manual pixelling or editing
  • 832*273 pixels, ST-MEDIUM res with dual screen interlace (see below how to convert)
  • Deliver in Atari native DU2 format as well as PNG.
  • Max three entries per person
The photos will be shown on a real Atari with a DU2 viewer that strips away eventual STe-colour bits.

Tools and guide:



3. 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

4. 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!

5. Lowres graphics

The resolution is limited to what the ST can display with overscan. Higher resolution 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

6. 32k music

Size limited music competition. 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.

7. Wild

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.