Mech KB noob, searching for a board with very particlar features

[CLAVDIVS]

I'm completely new to shopping for mechanical keyboards, and feeling a little out of my depth. I'm after a keyboard with a very specific set of features; I go into the details and reasons below.

Essential:
Matches the layout and dimensions of the classic Model M (I think) (EDIT: looks like I got this wrong, sorry)
USB interface (or one that a Raspberry Pi can use with an adapter)
Desired:
Status lights integrated into the lock keys
Trackpoint pointing device (or off-brand clone)
Tactile switches

The reason for this is that I'm turning a vintage portable computer (Amstrad PPC 640) into a Raspberry PI casemod. The first requirement is pretty much non-negotiable, because it needs to fit into the same physical space as the original keyboard once I remove it. I'm 99% certain that it's the same measurements as the IBM Model M, because of posts I've found elsewhere by people doing similar things. If it helps, I've measured from one edge of the keys to the other (specifically, the edges of the cutouts), and it's exactly 17 inches (or near enough that I can't tell). Elseweb, I found someone who got a Lenovo SK-8825 to fit with a little work.

The second requirement is also pretty important, because the Pi requires USB input. I'm not sure I can rely on, say, a PS/2-USB adapter, because I've read posts about then not working reliably with the Pi. However, if the keyboard in question is a modern one, I don't expect that to be a problem.

The integrated status lights are on the list because the PPC's keyboard has them. If the one I replace it with doesn't, that means I'd have to drill new holes into the case to accommodate them, and I'd really prefer to avoid that. I also considered drilling holes in the keys and running the LEDs over there, but again, I'm not experienced enough to know if that's a practical solution.

The Trackpoint (or clone of such) is mainly because I'll need mouse input at times, and I'd really like to preserve the retro aesthetic of this thing while it's in use; I feel like having a mouse plugged into the side will compromise that. Plus it would be nice to mix a little Thinkpad DNA into this ridiculous frankenbeast I'm making.

The switch preference is just, well, preference. I like being able to feel the click, but I don't want it to sound like I'm ringing the Bell of Awakening. (My current keyboard on my PC is just a plain old Logitech K120, but that's because I was broke when I bought it and just needed something cheap. I haven't been strongly motivated to replace it.)

I've been searching various keyboard vendor sites, but I'm having a hard time finding what I'm looking for. I don't know if it's because I'm not using the right search terms, or if my ideal keyboard just doesn't exist. This place seems to really know keyboards, though, so I figured it was a good place to ask.

So, does anyone know where, or even if, I could obtain such a keyboard? What do I need to be searching for and/or filtering by? Thanks in advance for any help you can give me.

[Myoth]

I think something like a G80-1501 would match almost all your needs except the trackpoint, that's probably the hardest to fulfill.

[CLAVDIVS]

I think something like a G80-1501 would match almost all your needs except the trackpoint, that's probably the hardest to fulfill.

Huh, I think that's the first remotely modern keyboard I've seen with the integrated lights.

I've found at least one mechanical keyboard with a Trackpoint, Unicomp's EnduraPro. No integrated lights, though, and only in buckling spring. But, you know, there's a reason why those features aren't under "essential".

[Findecanor]

Are you the same person that asked about this on Geekhack?
Over there, I suggested that you build a controller for the existing keyboard. Another option would be to replace the keyboard with a desktop Amstrad PC keyboard which has the controller in the keyboard module and not on the motherboard.

The Amstrad has a flat backplane and specific spacing between key groups. Those are the things that you would need to find a fitting replacement keyboard for. The IBM Model M (or EnduraPro) will not fit because it has a curved backplane and the spacings are all different.
Measure F12 and Print Screen from centre of key to centre of key (or, mean of outer and inner spans) and subtract 3/4" to get the horizontal spacing between key groups.

Then I think that you would have to get a modern keyboard and cut the case plastic between Alt and Ctrl keys. That looks like 1/2u on the Amstrad but it is more common on vintage keyboards to have 1u or none, where as modern keyboards with Windows keys have none.
If the horizontal spacing is 1/4u (3/16") and the vertical spacing is 1/2u (3/8") then you should be able to fit many modern keyboards, such as the Filco Majestouch (which does not have integrated lights though).
You might also have to do some surgery on the plastic inside the keyboard case to make it fit properly.

It is common among trackpoint modules in laptops to talk the PS/2 mouse protocol — which you should be able to connect with a PS/2 to USB adapter to one of the Raspberry Pi's USB ports.
You might be able to find an unused module if you look. However, if you look at old laptops, some are unfortunately too integrated into the keyboard and can not be taken out and used separately.
I would suggest mounting that in front of the keyboard. If you would place it inside the keyboard it would require a long stalk to reach through the keys.

[CLAVDIVS]

I'm not on Geekhack (yet), so that wasn't me. It seems like doing weird stuff to Amstrads is a more popular passtime than I realized.

It's been a long time since I've seen a Model M in the, uh, plastic, so I guess I'd forgotten how curved they were. Hrm.

I measured the keys as you said; from center to center (or between matching corners, etc.) it seems to be exactly 1 inch, making the horizontal spacing 1/4".

I just assumed some dremelling and gluing would happen at some point, and those plastic peninsulas between Alt and Ctrl would be the first thing to go. Soldering and wiring, though, I'm not as confident in my abilities there. Anything really sophisticated I'd prefer to avoid.

(Does "u" mean "width of one normal key"? I'm not familiar with that terminology, but that seems like what it might be from context.)

Ultimately, it's entirely possible, perhaps likely, that my ideal keyboard for this task simply doesn't exist, and I'll have to make some compromises. But I figured this was the place to ask, either in case it does exist, or to find something else I'll be able to work with.

(If I have to resort to a mouse, maybe I can find one that matches the period aesthetic.)

[Elrick]

(If I have to resort to a mouse, maybe I can find one that matches the period aesthetic.)

I use a Ducky Secret only because it has the ALL too familiar shape of the older Microsoft Mice produced before the MLT04 series appeared.

The Ducky Secret comes in an all PBT shell (to die for) and has a modern 3310 optical sensor capable of up to 5000dpi.

Hence I chose to stick with it when comparing all other mice that were and are currently produced.

[Findecanor]

I'm not on Geekhack (yet), so that wasn't me. It seems like doing weird stuff to Amstrads is a more popular passtime than I realized.

Here is that thread by the way.

It's been a long time since I've seen a Model M in the, uh, plastic, so I guess I'd forgotten how curved they were. Hrm.

It is not that easy to see. On the Model M, all keycaps are the same profile and the backplane is curved. On keyboards with a flat backplane the shape of the keycaps are curved to achieve the same effect.

I measured the keys as you said; from center to center (or between matching corners, etc.) it seems to be exactly 1 inch, making the horizontal spacing 1/4".

Do measure carefully. On a keyboard I have which is compatible with the Filco Majestouch, that same measurement is actually smaller than 1". (1 + 1/4) * 3/4 = 0.9375. The difference is about 1 1/2 mm.

(Does "u" mean "width of one normal key"? I'm not familiar with that terminology, but that seems like what it might be from context.)

Yes. I'm sorry for not explaining that.

[CLAVDIVS]

It's all good, I've done it myself.

I'm having a damnably hard time finding anything with integrated lock key lights. I just keep getting results for backlit keyboards. Is running the LEDs from their original location to the keys feasible, or will the wires get in the way of operation/wear out from repeated motion? I also had the idea of using fiber optic cable, but that might be even less practical.

Also: What measurements do I need to look for in a prospective keyboard to ensure that it fits? (I edited line in the OP about that, since I'd gotten it wrong.)

[Anakey]

i think that what you are searching for is going to be way too specialised to be able to be found even on vintage keyboards. I would say the only way to get all the desired points you have is to basically build the keyboard yourself which will involve a bit of work but will probably turn out cheaper and easier to make it to your exact requirements if you are willing to put the time into doing so that is.

[CLAVDIVS]

As I said, there's a reason not everything on the list is mandatory. If I know what I need to look for to make sure a keyboard physically fits, I can decide what else I'm willing to do without. I don't think a trackpoint is in the cards at this stage, and while I'm still holding out for integrated lights, I'll do without if I have to.

Building a keyboard I really don't think is a reasonable option for me right now; I just don't think my skill level is up to the task yet.

[CLAVDIVS]

Bumping the thread in hopes of a reply to my last question. I can make do with any keyboard that fits the required dimensions, but I don't know the jargon so I don't know what to look or search for.

[TheInverseKey]

Have you thought about the IBM Model M13 also know as the Trackpoint II?

Wiki: wiki/IBM_Trackpoint_II_Keyboard