Korg Prologue SDK Nerd Patrol


Cross posted from GearSlutz… Anyone know any more?

someone over on the elektron site is saying korg were giving away development boards at super booth…anyone confirm?

Lady Gaia

That’s basically what Etienne says in the video. He’s handing them out to people attending technical sessions at the show. They’re not for sale, and may never be. Incredibly irritating, really, but presumably those who had been in contact with Korg about the SDK previously were given some advance notice and invited to attend.


Pretty much the same as Lady Gaia, from the same source, but my read from the Sonic State video was that Etienne Noreau-Hebert was saying Korg had not decided whether or not they would distribute more boards after Superbooth. Sounded more like they were checking for demand.

My own ramblings:

The Dev Board has both processors (multi-engine and FXs) and provides the connections with a host to run without all the other stuff that would be there in the Prologue. So the parameter pass are on the host side. But no analog synth obviously, though i presume you can send note-ons from the host, but there is other stuff missing.

What i have not heard is what if any debug facility might be included on the Dev Board system, that i presume would be unavailable from the Prologue, without connecting to a JTAG connector inside the Prologue or such like. If there is no debug (break-points and variable watching, and printfs, etc) between the host and the Dev Board, then it seems less essential. It would then just be a way to develop without having to buy a Prologue, which Etienne seemed to be saying.

I guess before i heard of the Dev Board i was a ready to use my brain as the debugger – which from my experience is the preferred method. On the other hand on rare occasion a debugger is essential – on the really mean bugs.

Oh and i also assume that the Prologue will be resistant to crashes that prevents a program reload. I can’t see them setting this up open to the public where someone could trash their prologue with an errant pointer, or whatever, and have to get it serviced to bring it back. I think that’s the idea of the limited code area that is available for modification. (Now obviously you could get malicious and fancy and do all the work to over-write some flash code – but that’s your own damn fault then.)


I think you’re slightly wrong.

My understanding is that the dev board contains one of the microcontrollers that’s on each of the 16 (or 8) voice boards in the Prologue as well as its main CPU (also a microcontroller, just a much more powerful one). The main CPU runs the effects, but also takes care of all the things you’d expect it to do in a synth like the Prologue.

It’s effectively a single-voice Prologue without any of the analogue parts and without any of the controls where the analogue voice is replaced with an external audio input for testing your effects.

I am pretty sure that the code you’re writing is intended to run within an existing framework that will take care of any debugging facilities. I don’t think you’ll need or be given that kind of low-level access at all.

I also think you’ll be able to run the oscillator and effect code you write on your development workstation so that you can most of your development and debugging there. You probably only need to run it on the Dev Board or on an actual Prologue to verify that it fits within the memory constraints and to do performance testing.

The Dev Board sounds like a quick thing they made to allow interested developers an opportunity to explore the SDK without having to buy a Prologue first. This is probably also why they’re giving them out for free to selected developers.

Again, I think you won’t do much debugging on the device. This won’t be like traditional microcontroller development where you’re running stuff directly on the hardware. You’re more likely targeting a very well-defined API using pure C code that just as easily runs on your host computer.


There are two processors on the Dev Board – Etienne at 8:50 into the video points to the multi-engine processor – it’s the little one on the lower left of the board. Etienne had pointed to the FX’s processor (it likely does more than FX as well), that’s the larger one - and this is the one likely hooked to the ISSI ram chip. Both processors on the Dev Board are STM ARM chips.


Yes, that’s what I said. I’m pointing out that the larger processor is not “the FX processor”, but the main CPU that also runs the effect algorithms.

In the video he also said that they have 16 of those little ones, one on each voice board.


This is the inside of a Prologue 16 and you can see the processors 4 per board along with the analog circuitry

We’re saying the same thing then. Good to know. Sorry if i was unclear.


FWIW, they probably shouldn’t have called it a “Dev Board” because traditionally a “dev board” or “dev kit” has been some piece of hardware you must purchase before you’re able to develop software for something.

In this case, the dev board is not required to develop for the Prologue. It’s just a cheap giveaway they made to get people interested.


You seemed to be under the impression that the board was missing the main CPU from the Prologue and that it needed to be connected to a host computer for control.

My impression was that the dev board is essentially a Prologue with a lot of bits removed, but that it’s still running the exact same firmware on that big microcontroller that also happens to have enough power to take care of running the effects.

I might be wrong though. :slight_smile:


Much more details in a shorter video:


Here’s the SDK!


So I see there are now a few custom oscillators and fx available now for the Prologue. Anybody picked any of these up?


I gotta say… I love the sound of this synth. It seems to me that you can get some really rich and complex tones by layering in the third oscillator. As much as I love programming, sometimes you just wanna dial something in fast. I like the simplicity of the Prologue. Seems such a quick workflow and an amazingly rewarding sound to my ears!


Exactly how I felt after playing with one at Synthfest. Took the edge off Moog One desire. It’ll take a while but hopefully a Prologue will be my next synth purchase.


I’m very close to caving into temptation on a 16 voice… !!


Do it!


I probably will. I’ve never been any good at resisting temptation!! I’ll report back.


Just gonna quote this for emphasis because I’ve also been deeply confused about the purpose and nature of the dev kit.


On MW, there’s a guy complaining about persistent issues with the intonation of the lower notes ( E, F, F# ) of the keyboard, after 3 OS updates and so on.


The Gearslutz thread also mentions the issue.


I’ve been following a lot of the threads regarding this issue. This video make me chuckle.

I certainly won’t buy until it gets sorted.


I sympathize with the guy in the video - but it does remind me of “angry guitarist” videos in an amusing way.

I’m impressed with the amount of development that has gone into custom oscillators for a synth that has only been on the market for such a short time. I like what little I’ve heard so far of the demos. This could be the sleeper polysynth for Korg if they straighten out that tuning problem.


Oops just accidentally pressed the buy button. I’ll share thoughts on it, and the tuning issue, soon!!