Production keyboards with separate controller board?

[NathanA]

Are there many (...any?) well-known, commercially-produced 'boards out there that are still being manufactured & are readily available that have a design where the controller PCB is separate from the main PCB and is easily detachable?

In the early-to-middle 2010s, this seemed to be more common than I get the sense that it is today.  Probably for obvious reasons, too (specifically, manufacturing costs).  I am, for example, familiar with the various similar 'boards that Costar OEM'd to different vendors that used this design, which the great bpiphany in turn made third-party replacement controllers for with enhanced functionality.  But that slowly, as newer revisions of these boards were introduced, the controller daughterboard was done away with and the controller chip was integrated onto the main PCB instead.

Whether or not anybody is making similar third-party replacement controllers, are there any modern boards still out there -- either manufactured by Costar or somebody else -- that has kept this design?

It seems as though at least one old Costar board design might still be being manufactured and marketed: Filco's Majestouch 2.  Are the internals of fresh-off-the-factory MJ2s really relatively unchanged from when it was introduced over a decade ago?  Or is the MJ2 of today a totally different beast that just happened to retain the name?

Even if so, shame about the price...similar boards from Newegg/Rosewill and Cooler Master/CMstorm were like half the cost and virtually identical...

[gipetto]

most of the better keyboards went programmable so there wasn't any advantage in having a separate controller pcb, especially when most users were breaking the usb c port off after a few years and trashing it. but i guess you are looking for a full size programmable keyb specifically and not finding the choice you like in the market.
there's the unicomp model m of course, but i assume you are looking for mx switch support.

[Riverman]

The Das Keyboard 4 has the controller on a separate PCB.  I think the Majestouch 2 has everything on a single circuit board, at least the full-size model.  It's been a while since I've owned one.

[NathanA]

most of the better keyboards went programmable so there wasn't any advantage in having a separate controller pcb, especially when most users were breaking the usb c port off after a few years and trashing it. but i guess you are looking for a full size programmable keyb specifically and not finding the choice you like in the market.

Yes, you're very very warm.  My interest is multifold:

First, I'm more a software hobbyist than a hardware one.  I'm more interested in finding good quality, mass-produced keyboard options than building my own, and yes programmability is important.

Specifically, though, I'm looking for QMK support for the ultimate in flexibility (& to get away from most vendors' trash config apps), which is found on very, very few commercial keyboards (at least not without a lot of heavy hardware modifications).

I am looking for full-size options, yes.  Not super interested in TKL, and essentially zero interest in anything much smaller than TKL.

It would also be nice to not pay through the nose, so value is important as well.  I don't care about RGB at all, just a good solid typing experience.

The various Costar variations-on-a-theme back in the day were great: I could take a ~$100ish (maybe less when on sale!) board with 104 keys, discrete switches, & good build quality, throw a fully-assembled bpiphany replacement controller in it for another $30-40 with little trouble in like 5 minutes, and have an awesome keyboard for the money.

If most commercial keyboards made today don't have discrete controllers, that wouldn't be so much of a problem as long as the MCU that the manufacturer used had enough oomph to run QMK (RAM etc.), was supported by QMK, and could be flashed with third-party firmware (there weren't any protection mechanisms in place that prevented you from doing this either intentionally or not, like OTP ROMs or firmware signing etc.).  The main advantage I saw to a separate controller was that they could be easily replaced with something entirely different, and be done minimally invasively.

At this stage, I'm mostly trying to get a good idea of what the market looks like today, and what options there are when it comes to value-oriented mech boards that are both full-size and have QMK support (either via controller replacement or via reflash of existing MCU, or -- heck -- I'd take first-party QMK support but I doubt very much I'll find it).

I did recently learn about the Redragon K556 and the Sonix QMK port.  Rather intriguing...

there's the unicomp model m of course, but i assume you are looking for mx switch support.

I love buckling spring, and I don't care what anyone else says: Unicomp boards are good value for money.  But I'm not aware of any off-the-shelf QMK solution for them...yet.  There are some promising-sounding things on the horizon though (the Level1Techs product is not yet widely-available, if that's what you are thinking of).  (I'm also specifically interested in ready-made controllers for boards that are currently still in production, that is to say I can buy a fresh-off-the-factory-floor one from the manufacturer right now at a set price, not hunt down a decent specimen / take the time to restore it / etc.  So original IBM boards don't fit my criteria, nor do any of the discontinued Unicomp models.)

The Das Keyboard 4 has the controller on a separate PCB.  I think the Majestouch 2 has everything on a single circuit board, at least the full-size model.  It's been a while since I've owned one.

That's interesting that Das 4 has a separate controller board and yet nobody has come up with a replacement for it.  I'm guessing that's because it also has a built-in USB hub, so if you want to reproduce that feature, that adds complexity & cost.  I'm also seeing several threads of outrage against Das of late for various things, so maybe they have just fallen from favor in the broader community & so nobody is interested in giving their products the time of day anymore...

There seem to be references to "Majestouch 2" as early as 2011, and as far as I have been able to piece together, the "2" is really no more than a minor refinement of the original (and also NKRO was standardized, whereas there were original boards assembled both with and without the necessary diodes).  The DT Wiki doesn't outright say it, but reports seem to be that bpiphany's Majestouch and Majestouch TKL replacement boards are both compatible with Majestouch 2.  So the question is, did Costar at some point in the last 10+ years between its introduction and now silently reengineer the "2" under-the-hood while continuing to call it the exact same thing?

[gipetto]

there are multiple controllers for various model m on deskthority, one is wireless, the rest are wired. Since you are content with the model m and they will be around for the forseeable future you should go that route, even if you have to pay someone to assemble it for you. however, the diy controllers i have seen have only required through hole soldering ability so are within the range of mere mortals. others use the surface mount assembly services of jlcpcb, leaving the sockets and headers to be done by hand. i have used such a service myself and found it cost effective.
You haven't mentioned how many controllers you want. it's understandable if you wear out keyboards and require a new one every 4 years, but you should be able to transfer a custom controller between keybs. i suggest creating two controllers so that you can diagnose issues easier by swapping parts.