Creating A Contest-Winning Amiga Demo Soundtrack

The Amiga platform took the world by storm in the 1980s. Developed by a crack team and brought to market by Commodore, the OCS chipset brought high-quality graphics and sound into the home computer market in a way never seen before. These capabilities cemented the Amiga’s place in the demoscene, and it maintains an active development community to this day. [Hoffman] is one such member of that community, and has shared some of the hacks that go into pulling off a banging soundtrack in a cutting-edge A500 demo.

The Amiga has 512 KB of so-called chip RAM, accessible by the custom chips and CPU for all tasks. There’s also commonly an additional 512 KB in a trapdoor under the machine, though it is limited in the ways it can be used. With these limits in place, [Hoffman] was overjoyed when the rest of the team allocated him a full 200 KB of memory for the soundtrack. In order to make the most of this precious resource, hacking ensued.

[Hoffman] does a great job of explaining all the tricks involved in creating a compelling 5 minute soundtrack in just 200 KB of RAM. There’s discussion of compression, sample sizes, and the vagaries of the ProTracker format. Smart hacks such as prioritized sample loading and pre-rendering drum loops also help to get the project over the line.

It’s a great write-up, which clearly explains the strategies used to help build a world-class demo soundtrack. [Hoffman] promises that the tricks used by the rest of the crew are equally as impressive, which we’re sure helped Eon to win the Amiga Demo Compo at Revision 2019. We’ve featured Revision winners here before, too. Demo video after the break.

[Thanks to Greg for the tip!]

11 thoughts on “Creating A Contest-Winning Amiga Demo Soundtrack

  1. Actually, the “real” Amiga came with 256kB of RAM and was extended to a whopping 512kB (speaking of the only Amiga that’s worth being called that way, the 1000). Its video was also limited to garbage (Never Twice t’ Same Color – NTSC) until something usable was available (PAL).
    With 200kB of RAM you can do a LOT, even in sound. Remember how much RAM synthesizers and wavetable players had in the beginning – it’s not all about sampling and wasting TB on your harddrive just to play a sound .-)

    That said, the demo is … nice.

  2. Now this is the sort of quality hacking we need to see more of as microcontrollers approach the A/V capabilities of these systems these sorts of tricks become relevant again.

    Would absolutely love to see some of the graphics routines used in demos.

  3. The Amiga was amazing machine for its time. It was so far ahead of itself. Remember getting my Amiga and was blown away by it. Glad to still see it in 2019 and people doing stuff for it. I still have my Amiga 1200 with lots of upgrades on it like usb,powerful graphics card,ssd drive,etc. Good times back then.

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