Ess Mattisson is a sound designer, developer, and co-founder of Fors.fm, an independent developer of software instruments known for its innovative Max for Live devices and plugins. At this year’s SuperBooth26, he presented a new and unique piece of software – the FMS groovebox for the Gameboy Advance – that greatly intrigued us and made us reach out to Ess for a quick exclusive interview about the FMS and what motivated him to develop new software for a twenty five year old videogame system.

STROMKULT: We previously talked about your Fors.fm work in 2024, but you now have something new, the FMS. What exactly is it?

Ess Mattisson (Fors.fm / Lo-Bit Club): Basically, the FMS is a new piece of software — an FM-based groovebox — for an old device, namely the Gameboy Advance (GBA), a handheld video game system that came out in 2001, so it is turning 25 years old this year! You know, I actually have a background in chiptune music, which I got into when I was 14 or 15 and never quite got out of (laughs). And I think especially in the last two years or so, there’s been more activity in the chiptune scene again after it went a bit quiet for a while, with more music and new software. 

So I just felt inspired to do something in that direction. And the way I always work is that I come up with a concept, a logo and a name, first before I start working on anything else. So I had the concept — I even made stickers and said to my friends, just wait, this will become something soon (laughs) — and that then turned into the FMS software.

The FMS is being released under the new Lo-Bit Club brand, could say a little bit about that?

Around the same time I started working on the FMS software, I also had the idea to start a kind of chiptune label, and so a friend who is a Chiptune musician said let’s do a collaboration, and we did a night in Gothenburg that was quite successful and we’ll probably do more events in the future. So Lo-Bit Club is a place for stuff made for those lower bit devices — mainly old video game systems — and then it just made sense to also put FMS there, in the low-bit-club (laughs). 

So the FMS is technically a “game” for the GBA, right? What kind of sound engine does it have?

The FMS’ sound engine is a 2-OP FM synth — using the Direct Sound registers of the GBA with custom DSP — of which you have four identical channels, plus a noise channel that uses the original GBA hardware’s internal noise generator. The FMS is actually somewhat similar to some stuff I’ve done for Fors, since internally, it is a modern 16-bit FM synth implementation with pitch envelopes, fine-tune ratios and feedback. But the output is 8 bit, so you get that lo-fi sound, and the code is not based on any previous Fors synth, especially since the GBA’s CPU is not very fast and you only have 32kb of internal RAM, so you have to work with very small margins in order to squeeze everything in (laughs).

Do you need the GBA hardware to run FMS?

You can run it on the hardware if you have it, but you can also run it on anything that can run GBA emulator software — which these days is basically any computing device, I even saw that some people are running it on their phone (laughs). There are also all of these Linux-based Chinese emulator handheld devices now that are quite nice and emulate the 8bit output, so they sound quite similar to the original hardware. I think with the purely digital emulators, the noise generator part is slightly less accurate, but it’s just noise so it should sound mostly the same (laughs).

Since it is a groovebox, there is also a sequencer — how many steps and tracks does it have? 

The sequencer was really inspired by the work of Nanoloop, who has made software for the GBA, so it is a bit of a homage to his work. There’s a max of 16 steps per track, of which there are four. Each track has 128 different patterns, and all of these patterns can be mixed and matched. There are also auto-echoes for arpeggios, ratcheting, note echoes, as well as a meta sequencer and Elektron-style trigger conditions — which were actually inspired by Nanoloop when I worked at Elektron, so it is all a big Nanoloop-circle of inspiration (laughs). So in a sense, it is a bit limited, but there is also a lot you can do within that.

And of course limitations can also be creatively inspiring. 

I think that’s definitely a part of why I wanted to make it in the first place. I’ve always liked making music on these gaming handheld devices because their limited control scheme makes them really easy to work with, you don’t need to think so much and you can really build muscle memory with those buttons.

You know, from a hardware design standpoint devices like the GBA actually are very luxurious; on a tactile and ergonomic level, the feel of interacting with the buttons and everything just feels amazing. The amount of time and money that Nintendo put into the hardware RND and production is on a completely different level — they sold over 80 million units of the GBA! — than basically any synth manufacturer, we will never have buttons this nice (laughs). They are also basically indestructible, I remember when we were filming some marketing material for the FMS on an island, we accidentally had a GBA unit wash away, and I think the PCB actually survived (laughs).

How do you integrate the FMS into your studio when running it on the GBA hardware?

You can use the device’s 3,5mm headphone jack as an audio output since it goes both ways. There are also sync options, I wanted it to be able to sync with the rest of your gear, otherwise it’s not that fun to actually use in your studio workflow. So you can get sync using the link-cable port on the GBA, which can send all kinds of data, including MIDI and CV, and you can find MIDI-in cables for the link port on Ebay.

The FMS is only 10 Euro — and the Fors.fm products are priced very affordably as well — and there is no copy protection, which seems like a quite unusual model in the software world, so I’m curious about your philosophy behind that.

You know, the software market can be quite strange. Like, at first, we didn’t really want to do sales — like ValhallaDSP, where all plugins are $50 and there are never any sales — but then we got so many emails during Black Friday about sales, so we were like okay we’ll do sale (laughs), and it does help. But we generally try to set our prices to be favorable to everyone, where the price makes sense for us business-wise, but it’s still relatively affordable; we want to be empathetic about people’s financial situations.

I also personally find these very extreme DRM-strategies of many plugins quite strange, where the plugin’s copy protection is almost like this spyware on your computer (laughs). I don’t subscribe to the idea that DRM necessarily helps sales — I think if people pirate it, they wouldn’t have bought it anyways — and it’s important for me to respect the customer. So we basically don’t have any copy protection (laughs), which is perhaps a bit of a radical approach, but as long as we can pay our bills, we are happy and thankful doing it that way. And I think people do take note of that relationship of mutual respect, and it is part of why people support us.

Last question: who are your three favorite chiptune artists?

My favorite chiptune artists of all time would be an artist called XIK. I just love his album “Baud Of Passion”. I also love the artist Cow’p. The third would be HIZMI from Japan, who in place of a video game console actually uses an older Japanese computer with a really nice Yamaha FM chip — to me, he is the FM god, he is the best (laughs).

You can find more information about FMS and purchase a copy here.