Review of Unicomp PC122 USB

tobe_b

23 Sep 2023, 17:50

Unicomp’s offerings are somewhat well known in enthusiast circles, but larger keyboards are currently not en vogue and there is much less information out there regarding the 122 key terminal keyboards by Unicomp. So here are some thoughts from a Linux user who does not mind using screwdrivers and hacking on QMK keymaps in C.

While I already have a 1999 IBM battleship (see viewtopic.php?f=7&t=28152) that I at some point want to convert to QMK, I need a second keyboard and got really used to the large layout. So I reached out to Unicomp.


tl;dr
  • You need the RP2040 controller to put QMK on this and make good use of all the keys
  • I wish there were more color choices
  • The known quality issues of Unicomp products apply, but I do not think they are real showstoppers
  • Springs are much stiffer than the IBM models
  • If you want such a keyboard at this price range and do not expect perfection, then do get it, it is a good product IMHO

Obtaining the keyboard

Unicomp prominently offers the PC122 without any customization options on their website. After decades of computing, I am only productive using a German ISO layout. This is offered in Unicomp’s “Keyboard configuration tool”. You should go for either PC122-3270 or PC122-5250 with USB. The layout is slightly different between those two options. I went with the 5250 because I liked some of the prints on the keys better (I planned from the start to customize the layout anyway). Enticingly, a pearl-colored chassis is on offer, but I was informed that they ran out of those and do not plan to reintroduce them in the foreseeable future. So I went with black plus gray keys. So much for nostalgia.

Furthermore, they are in the process of switching to Raspberry Pico RP2040 based controllers, but—importantly—do not ship them currently in 122-key keyboards sold internationally. International customers have to shell out $24 in customization fees (best to inquire beforehand via the helpful support). The fact that QMK works on these controllers was essential for my buying decision, so I happily paid the extra. If you are using this keyboard on PC, you presumably want to program the extra keys, so I strongly recommend getting the RP2040 controller. Otherwise the default keybindings are just legacy compatibility things for terminals, which are completely stupid for scripting (e.g. F13 is really shift+F1).

Shipping took less than 2 weeks from ordering to the keyboard (plus extras) arriving at my door in Germany.


Out of the box experience

The keyboard looks much, much better than the tiny photos on the website suggest. Not sure my crappy phone camera can do it more justice (note that this is after switching out many of the keys and the LED overlay, the default is all gray keys and a black LED overlay):
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The weight is lower than the original IBM and the plastic feels cheaper. There is some creaking, especially when pressing on the sides. The texture is partially uneven. You can see on my photos that dust is easier to notice on the black chassis. There is one spot in the recess behind the function keys that is filled with a plastic blob, seems to be a clear manufacturing problem.
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The New Model M (which I also ordered out of curiosity, but will probably sell again: not enough keys 🙂) is much better in that regard: It seems that the tooling for the 122 key models is still the old, worn one. That being said, I still think the keyboard looks good and will serve me well. The aesthetic blemishes don’t bother me, but they should be mentioned in a review and are noticeable.

The indicator LEDs are blue, which is not super popular around here. I tend to agree. Yellow LEDs might have been quite nice and novel, perhaps. On my specific RP2040 controller, the blue lights are not blindingly bright and they happen to be offset a tiny bit from the intended positions. These things together make them the optimal brightness for me when they shine through the label, although I’m not sure this was intended or a happy accident.
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If your LEDs are too bright, I would propose the quick fix of sticking a small piece of toilet paper or some similarly thin paper between the LEDs and the case to reduce brightness → easy fix IMHO, I did it for the New Model M.

The keys look good. They nowadays use gray instead of pebble. This bothered me in the images, but is actually pretty good looking in reality. Tastes may vary and those nostalgic for IBM colors will be disappointed. There are some really minor alignment issues with the print for “special” keys, such as the “Menu” key. Some of the gray modifier keys have slightly different shades of gray. This is most notable for the “Ctrl” replacement for CapsLock, which—to be fair—is sold separately and might thus be from a different batch. There is some slight difference between Alt and the spacebar.
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Again, I am a picky person and it doesn’t even bother me at all. The true perfectionist might be annoyed.

Note that the keys are single pieces without the detachable cap. As far as I know this is regarded as the better version. I tend to agree, but the comparison between my old two-piece IBM keys and my new single-piece Unicomp ones is not entirely fair due to possible wear.

Finally, the most important thing: The feel of the keys. The springs are quite stiff. I have a bog-standard IBM Model M from 1992, which has the lowest actuation force, and an IBM battleship from 1999, which is quite a bit stiffer. The Unicomp requires even more force than that. What is interesting is that the 1999 IBM has a somewhat “mushier” feeling and that the Unicomp springs feel a bit more “crisp”. I think I prefer the lighter touch ones, overall, but this is ultimately personal preference. All of them feel high quality, IMHO. It should be noted that some of the keys would not click out of the box or when pressed off-center. Most could be fixed by reseating the key (making sure that the spring does not touch the sides of the barrel and maybe experimenting with tilting the keyboard). Some required turning the spring a little bit until the key felt good (use a chopstick or over-sharpened pencil to carefully twist the spring without removing it—takes some experimentation and care, please do not destroy your springs). After that I would say that you get the genuine buckling spring feeling. And it feels great. The texture on top of the keys also feels good to me.

Keyboard is plug and play via USB and the keys match the printed chart that came in the box. So far, so boring.


Slight modding

I have never in my life used an IBM 3270 or 5250 terminal, nor do I foresee myself doing this outside of a museum or similar. Thus, I need QMK to unleash the potential of this thing. Here's how to do it:

First, you need open the keyboard. They switched to screws with a Philips 2 head, so everybody should own the tool to open it. On the right side, over the numpad, is the controller. In case you need to replace it: It is fastened with Torx screws, so dig a little bit deeper in your toolbox. I do not like the way the controller is mounted, it seems a bit fragile to me. The controller is inserted at an angle and the pressed down with a little plastic clip and then with two screws. Contact is made directly between the membrane and contacts on the controller PCB. Everything is a bit fiddly, so observe well how the old controller was mounted in order to install the new one the same way. Nevertheless, I managed on the first try.

Currently, source code to support this controller can be found at https://github.com/purdeaandrei/vial-qm ... tides-2862. Hopefully it will be merged into QMK. I did not want to use vial, but fiddle with the .c files directly (what can I say, I prefer Emacs to web GUIs and some things I want are only possible in C). Thus, I had to install QMK (see their excellent docs) and copy the source code for the new Unicomp models in there. You will most likely want to make your own layout, so copy the “default” layout (which already mostly matches the modern standard layout) and adjust as desired. Then compile, obtaining a .uf2 file.

The Raspberry Pi people have two more things that you might need if you want to backup the original firmware: The SDK (https://github.com/raspberrypi/pico-sdk) and picotool (https://github.com/raspberrypi/picotool). On Linux: Put the SDK somewhere and set the PICO_SDK_PATH env var to that path, no need to compile. Then go into picotool’s directory, and

Code: Select all

mkdir build, cd build, cmake .., make
Unplug the keyboard (still opened up), push and hold the little "BOOTSEL" button, and plug in the keyboard. All LEDs should be on and you can release the button. Note: the keyboard is currently not acting as a keyboard, so you need another one to issue the commands!

I would backup the original firmware just in case:

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sudo ./picotool save -a FILENAME.uf2 -t uf2
For installing the QMK firmware, the Pico pretends to be a USB mass storage device, so just drag the compiled .uf2 file in there. The keyboard automatically resets and is ready to use! Neat! I would advise to assign a button in QMK to put the keyboard into flash mode so you don't have to open it again. Reassemble the chassis. One thing I found annoying, was the cable strain relief. It is very fiddly and loved jumping out of its socket. But if it works, you’re done! That was comparatively easy, actually, and if you are lucky enough to get the Pico installed at the factory, you will be able to flash that thing in maybe 5–10 minutes.

(I followed partially this guide: https://sharktastica.co.uk/guides/unicomp_pico; thanks for writing it!)

Finally, I am a sucker for (weird/uncommon) keys and I ordered a few extra. I also thought that the gray keys look good, but the white+gray keys on the New Model M look amazing! So I switched them out. (Why is there no option to get gray+white or pearl+pebble keys? Unicomp clearly makes and sells them! While gray+white looks good, I still prefer pearl+pebble.) The LED overlay in black looks kinda bad (weird symbols, printed way too big for my taste). Weirdly, the white one looks nicer (I ordered it from the misc parts page on a hunch) and looks great on the black chassis. All in all it somehow reminds me of the Death Star control room now, and I mean that in a good way.


Notes on the layout

I got used extremely quickly to putting Esc to the left of the number row instead of above it. I am now convinced that it belongs there, much more comfortable to reach somehow. I understand the people who miss the block on the left. Linux GUIs nowadays use the Windows key (or “Super” key) a lot, but having it further to the left does not really bother me as much as I thought (it’s the red Panic key; the Windows logo looks ugly and I don’t like unrelated corporate branding on my keyboard, thanks). Willing to accept this for the Esc placement. The Record/play keys actually record keystrokes and play them back (dynamic macro in QMK). The menu key doubles as Fn when held instead of tapped. QMK rocks. The other left block keys were mapped in my OS’s keymap to several symbols I use regularly that are not easily accessible otherwise. I love the media keys at the top being actual buckling spring keys and not some cheap thing added as an afterthought.
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I also enjoy having one more key on the numpad: I converted everything to standard layout and put a “.” key on the additional lower half of where the plus key would normally go. This is super useful on a German keyboard, where the default decimal separator is “,” because I can now type numbers both in US and German style based on current needs and what type of input is expected by the application/website. Makes me use the numpad more often, actually. The arrow cluster is of course less ergonomic than the inverted T, so I just made the middle key an additional "down" key. I had zero issues adjusting to that. The “Enter” symbol is there because it looks better than two down arrows, i.e., pure aesthetics.
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I would encourage PC122 owners to go wild with keybindings for the extra keys for a while to see what works for you. I am happy with many keys and I love overthinking/revising what to do with them. Layers are nice, but sometimes you have a coffee in your hand and want to skip a song. More keys = better for me, and you—dear reader—will know if you are the same.


Verdict

Putting QMK on these is a must (unless you really only connect these things to an appropriate terminal). More color choices would be nice (chassis and keys, classical IBM colors) and some improvements to the finish of the chassis would be welcome. Why no Pico controller option from the factory for the rest of the world? The classic Model M style construction also means this will require a bolt or screw mod at some point. You also might need to fiddle with the keys/springs after shipping.

Despite these caveats, I would still fully recommend this if you want a 122-key keyboard of this style. In this price range, there’s nothing else—as far as I know not even with MX-style switches and definitely no buckling springs. Even if you pay much more, you can’t get anything new in less than 2 weeks. It’s a good product so far (let’s see how it holds up over the years) and it looks good. Feels even better. Thumbs up!

User avatar
browncow

28 Sep 2023, 12:02

Very nice in-depth review. Basically anwsered all my questions as i was starting to get a bit interested in the new unicomp boards :)

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