deskthority

Quick summary: I used Model Ms as a kid and loved them but was a mac guy so I only used them on a at school and on a gaming computer back in the late 90s/early 2000s. Couple of years ago, I had been lamenting modern Cherry boards on a Sprinter forum and somebody turned me on to the Unicomp New Model M Mac. I loved that… until I pulled out one of my IBM model Ms and compared. The end result of this was concluding that to use an IBM Model M on a mac would be difficult… Until I saw Dr. Ran’s video on an M122, and the concept of a Soarer’s converter. I concluded I could set up the standard modifier pair as Command and Option, and the bottom two of the left functions as L and R Control. (Concision is a virtue I don’t possess)

This ultimately lead me down a rabbit hole that has resulted in me currently owning 3 139140s (2 of which I owned before this), 2 Unicomp New Model Ms, 6 type I M122s, 5 Unicomp 122s, and an IBM Model F 122, with one of Joe’s beamspring 122s on order, and quite a lot of custom caps. Deep rabbit hole. (and that's not including non-IBM derived boards, which mostly is a Focus FK-9000)

The first 122 I bought was a Type II, shocked by the prices of type one, and it needed bolt modding. In trying to do that, without disassembling the assembly, I destroyed the thing. I ended up donating it to ClickyKeyboards while ultimately also buying a pair of Type Is for my home office and van, the van board being bolt modded by Clickykeyboards.

I felt sore about failing the bolt mod of the Type II. I’ve continuously felt sore about it. I also ended up with a cracked case Type I. I saw an ebay auction for 5 non-functional (their description) Unicomp 122s from 2013, and I bought the lot for $90; I figured for $18 a board, I could conquer bolt modding. Maybe. I also have the ambitious project in my head of eventually putting the mounting plate and possibly barrel plate of the cracked type I in a Unicomp. I have concluded this will involve quite a bit of work with my Dremel and drill press. I insist that nothing is impossible but skiing through a revolving door!

All of the boards had popped rivets; one works so well you couldn’t tell, though, another all keys click but a couple are sponguey; the remaining three have non functional keys, all due to popped rivets from my observation. One of those boards is earmarked for the Type Is heat-treated mounting plate already.

Yesterday where I live we had a blizzard, and thus I was going to be inside all day; directly after my after breakfast shower, I took the second most broken of the 3 broken boards (the most broken being designated for the type I’s chassis) and set about getting to work. There were a few early aggravations; the first is that my dremel doesn’t have a chuck adapter and couldn’t hold a 3/32nd (iirc) bit; so I used my drill press for this part this time. The other was, while trying to cut off some of the rivets, gave myself a 1 1/4” incision on my right thumb (yay for being lefty…) with a xacto. Not terrible, thankfully.

I proceeded on and drilled out the holes (badly). I think I have concluded that in the future I will use the method of a drill press, and drilling out the holes on popped rivets first, screw them, then cut off some of the unpopped rivets, drill them, screw them, cut off the rest, and drill those, then fully disassemble, clean, re-assemble, and put in the nuts.

Anyway, I was at it all day; I emerged just before dinner time. I no longer question the price ClickyKeyboards charges for doing this work, if I ever did. Among my issues was I had partly reassembled the board before I realised some of the flippers had dislodged. But by dinner time I had assembled the thing… except I never put the nuts on. It was too late, my back hurt too much, and I needed a break. I had the thing basically reassembled, and after dinner I took in the unit, plugged it into a PS/2 active adaptor (but not VIAL), and… I thought it was dead. This, I admit, was not uplifting. Although all but a few keys did click!

This morning I decided to play with it more. And I finally got it to output stuff; it output only on a few keys, and what I would call Mac Option Codes; the symbols that come out while holding the option button while typing. I thought this might be a controller issue, but it happened with a second controller I tried. I finally found a keyboard matrix tester online; it wasn’t setup for a 122 (a link to one that is would be wonderful… lol) but I think I got to the root of the issue.

Only a few keys register in a particular area of the board that I would say is the most tight. A key with a busted spring is frequently on (I didn’t want to go to the trouble of a spring swap until I got the rest of the board working, because it would be a waste of time and parts if I can’t get the rest of the thing working), and… the ALT key is constantly pressed, which is set on my mac as option. Which explains the option codes, duh.

My project for when I get home today is to pull the stems off again and tighten down as many nuts as I can. I suspect that is the problem. Any other suggestions would be welcomed! I don’t care about the board; this was intended to be a surgery teaching cadaver, essentially. That’s what I bought all 5 for. But I want to get it working if I can. I hate when I try to fix something and fix it so nobody can, lol!

I don't bother with the bolt mod. I prefer to do the screw mod instead. Easier and don't have to fuss with all the extra parts and steps. I've done about 6 boards myself with success on all of them expect one that had bad membranes. I had to order new membranes from Unicomp and a new controller. Old controller wouldn't work with the new membranes. After that the board worked great. Probably helps that I work with my hands for employment and use to assemble models throughout my life. I did have to disassemble a few after I realized I placed some keys in the wrong place and what not. Had my headaches myself doing them. Keep at it. You'll figure it out with experience.

I shave off the rivets with a sharp chisel and use flush cut cutters to remove the rest of the rivet after I separate the barrel plate from
the back plate. Next project I'm probably going to try flush cutters on everything. I also do two screws from the top side down as alignment pins for lining up all the membranes and backing plate. On the membranes there are a few holes that aren't oblong and that is what I use for the alignment screws. Fit nice and snug.

First one I ever did here viewtopic.php?p=512497#p512497 Its a 122 also.

did you pull out all the keys before doing all that? Those create ~6.5kg force (closer to 8kg on F122) pulling the barrel plate away from backing. Removing that force makes the process way easier - like, you can chop all the rivets, then drill the barrel plate conveniently separated from everything else, check all the springs and assemble everything back without trying to overcome any forces.

Yeah, I did pull out the keys, DMA

Thanks for the advice, Falkenmouth.

I've screw-modded around 100 Model M boards. I started in 2022 (never having before held an IBM keyboard) by buying a few cheaper keyboards from ClickyKeyboards that were gone over and rebuilt/restored. I "reversed engineered" the 2 or 3 keyboards to see what ClickyKeyboards did. I then exchanged emails with Brandon Ermita about his methods, bolt modding vs screw modding, and some other odds-and-ends. Mr. Ermita seemed more willing to share his expertise when I intimated I wasn't starting my own "mail order Model M repair/refurbish" service.

I live in a large metro area (just northeast of Dallas) and do, occasionally, screw-mod and clean up Model M keyboards for other people, but mainly for free, and most of my "customers" are friends or local tech geeks like me.

My first time screw modding a Model M (a 1988 '1401) four years ago didn't go so well, but things have progressed to the point to where, now, I can screw mod an M122--from totally dirty, nasty, nonfunctional with 90% broken rivets (actually called "tenons" in IBM parlance) to completely functional and cleaned up--in about three hours.

My latest screw mod (Feb. '26)

It REALLY helps to have the right tools, so here's exactly what I use:

Dynamite Nut Driver
https://www.amazon.com/dp/B000BQ4XP6

Gateron Switch and Keycap Puller
https://www.keychron.com/products/gater ... cap-puller

Pyrex 1.5-quart Mixing Bowl
https://pyrexhome.com/products/pyrex-1- ... ixing-bowl

Hyper Tough 5" Flush Cutter
https://www.walmart.com/ip/Hyper-Tough- ... /189121458

Dremel 4300 with white LED attachment
https://www.dremel.com/gn/en/p/dremel-4300-f0134300ja
https://www.homedepot.com/p/Dremel-4300 ... /311541231

Dremel 1/16" drill bit (comes in a package with other micro bits)
https://www.homedepot.com/p/Dremel-Rota ... /100096934

Wiha 96706 Torx Screwdriver
https://www.amazon.com/dp/B000T9SDB0

Thread-Forming Screws for Thin Plastic, Zinc-Plated Steel, M2x6mm, T6 Torx Drive, Packs of 25
https://www.mcmaster.com/96817A312

Some other materials are necessary: 1/4" nut driver, Dawn liquid dish soap, workshop or kitchen sink, a toothbrush or similar, plastic pry tool (dull edges) or wooden popsicle sticks, paper towels, old books for holding the sides of the assembly, and a few other items most people have around the house.

And here's what I do (combined instructions for 101-key Ms and M122s):

1--Pull the keycaps, separate them (in the instance they're the 2-part keys), place them in a glass mixing bowl with soapy water
2--Remove the four (or five) screws and pull the keyboard apart (remove the top case first)
3--Stick the top case in warm soapy water (in a sink) and let it soak. (Sometimes if the case isn't so dirty, or has stuck remnants of stickers and security tags/labels, I just clean the whole case with 91% isopropylol.)
4--Remove the grounding cable with the 1/4" nut driver; gently disconnect the controller from the membrane sheets and lock LEDs
5--Use a shop vac to gently vacuum the controller and all the parts except the keycaps and the top case
6--Use the flush cutter to cut the tenons off the back of the steel backplate (I do it this way instead of using razor blades or a knife)
7--Gently pry apart the assembly using the plastic pry tool or wooden popsicle sticks
8--Dump out the springs and flippers onto a clean surface like a table or desk
9--Set the books on a sturdy table or desk. You'll need 3"-4" of space under the barrel plate so you have room to do your drilling
10--Pull out the rubber "blanket" and plastic straw things (the ones on older Model Ms, if present); put these items with the screws and other fasteners
11--Use the flush cutter to trim the tenons down to make them "even" with the rest of the plastic on the barrel plate
12--I use the Dremel with the specified bit to drill into the barrel plate at each tenon point. Paraphrasing Mr. Ermita's instructions: use the lowest setting on the Dremel with the LED attachment turned on; go slow and steady. You don't need to use a drill press, clamps, or anything else, and it doesn't have to be too complicated. Just go about it deliberately. I'm pushing 50 and have poor eyesight, so sometimes I use an old/large magnifying glass (holding it in my left hand) while I operate the Dremel with my right hand. Once you get the hang of it, you should be able to do a bang-up job on all the tenons on an M122 in less than an hour. I usually can get the whole thing drilled in ~20 minutes. It's not necessary to drill out the row of tenons closest to the bottom edge of the barrel plate (the edge facing you when you type).
13--I drown the drilled barrel plate into the sink where the top case is. This where a toothbrush or small sponge comes in handy. Scrub scrub scrub for a good 15 minutes and then rinse the case and the barrel plate in warm water. I run everything through a ton of paper towels and a handheld hair dryer. Sometimes if I'm having a bad time, I might let the barrel plate sit out overnight, sandwiched between paper towels, but in general I can get everything perfectly dry in 20 minutes or so. Sometimes I hand-wash the keys/keycaps, sometimes I don't. If I do, I dry them with paper towels and a lot of Q-tips. (Isopropylol is good for keycaps if you don't want to bother with washing them in soap and water.)
14--Set the barrel plate on the books, using books on the left and right side to hold the barrel plate by its edges. You can also set books at the front and back of the barrel plate to give it more support.
15--Now the springs and flippers go in. I don't think it's necessary to clean the springs and flippers. Usually they're fine. I also don't think it's strictly necessary to keep the springs and flippers in the exact same locations (keys) at which they started.
16--Now it's just a matter of reassembling the whole thing. Be sure not to overtighten the screws--the tenons/rivets on the original assembly weren't that tight to begin with.

On an M122, you can test all 122 keys individually in Vial in any OS (if you have a converter that supports Vial).

That's my basic process. I'm doing this from memory and recovering from two days of surgery as I write this, so I'm sure I'm leaving something out (not intentional). The most important thing I can say is to NOT OVERTHINK the process and have fun doing it--if you're having fun, the board will turn out better.

Thanks, I got some items in my ebay cart now. Some of those will make it much easier, for sure. Definitely going screw mod next time. T6s in my McMaster cart for the next time I place an order with them, too.