Author Topic: IBM Model F-122 terminal keyboard - Harry's ANSI modification  (Read 39455 times)

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Offline fohat.digs

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IBM Model F-122 terminal keyboard - Harry's ANSI modification
« on: Fri, 20 September 2013, 10:40:56 »
This guide may help you if you are considering doing this conversion on your IBM Model F 122–key “terminal” keyboard, in order to get a full–size, near–ANSI–standard, Buckling Spring, Capacitive Switch keyboard that will connect to a 21st century motherboard.

And a sincere bow and link to an amazing guide that makes mine look crude and cheesy by comparison:
http://deskthority.net/workshop-f7/ibm-terminal-es-to-us-iso-lot-of-pictures-t9745.html

You will need to read Soarer’s Converter thread (“XT/AT/PS2/Terminal to USB Conversion with NKRO”) for the use of the “Teensy” breakout board and electrical juggling involved, because it details the “electrical” modifications that are required to make the keyboard talk to a modern motherboard via USB. Make sure that you are comfortable with that process before you waste any time on my little subset guide, which only describes “physical” modifications to the mechanical components of the box.

IBM Model F 122-key terminal keyboard - typical ebay purchase



This is pretty good and clean as these things go - Don't worry, be happy


After several hours of frustrating work, you can get this:



And you can do fun and interesting things with color, or keep it simple:


This is not “rocket science” or electrical engineering, or tool & die shop, but it is a project that requires some moderate time, energy, and ingenuity, and at least a couple of hours at the workbench handling basic tools. This article is a mere supplement to the earlier works, to help guide you through the drilling and bolting of the physical pieces of these ancient beasts. (Rule for Life: Using your digital camera to take a few shots during the project, starting early in the disassembly process. This is helpful when you forget how all the pieces fit back together.)

Beyond the usual screwdrivers, pliers, wrenches (7/32” / 5.5mm and 9/32” / 7.5mm sockets), and hammers, you will probably use some small (#4) nuts, bolts, and washers, and probably some paint and glue (I like JB Weld epoxy). I have heard people crying about how hard it is to put these back together, but if you spend $20 or so and buy yourself some clamps, it will be “orders of magnitude” easier.
You will also need to gather the keys and insert sleeves that you will need to replace non–Model–F keys. In my case, that is: Enter, Backspace, Backslash, and Left Shift, along with 4 “centered” barrel sleeve inserts. After that, you will probably replace a lot of keycaps, but that is up to you. Unicomp is your best source.

Presumably you already have an IBM Model F keyboard, 122–key terminal type to work with. These are nothing like “space-saving” or “lightweight” models. Even the IBM Model M seems wimpy in comparison to these steampunk behemoths. This is not to say that I like the monstrous size – my ultimate preference would be a straight, full–numpad Model M (or with the slightly smaller footprint of some of the newer Unicomp models) but with capacitive switches and the “feel” of the Model F. I have a Model F AT but the layout is too problematic to allow me to enjoy using it. And the Model F XT feels even better, but the layout is even worse, so I went through this exercise to re-create the Model M configuration as best I can.

My F–122s are 6110345, 6110347, and 6110688 part numbers, with large old–style 5–pin DIN plugs in 240 degree configuration. I was lucky enough to find one good one and a few others in varying states of disrepair, from which I created 3 working specimens using the salvaged parts. Needless to say, I ruined multiple components during the course of my quest, so it was crucial that I had extras. I am hoping that this will spare you repeating (at least some of) my mistakes.

Let me reiterate that this article is strictly the “shop” portion of the project, and that Soarer provides all electronic procedure for this undertaking. I am making up names for some of these pieces, if there are “proper” names, please let me know. For Soarer’s Converter, you will need a Teensy 2.0 from pjrc.com (I recommend “with pins” and a small “breadboard” to mount it on), a mini–USB cable, some wire (a foot each of black, white, red, and yellow makes it smoother), solder, and a continuity tester is very helpful.

For this one, I installed the Teensy internally and bolted it to one of the unused inside brackets.





Teensy on small breadboard, mounted to interior bracket




Always useful to have these wiring diagrams handy.



Here is an "outboard" Teensy in a project box with pigtails.




http://www.pjrc.com/store/teensy_pins.html

HERE  WE  GO !

If you are tackling this project, I am assuming that you can take the juggernaut apart on your own. If not, turn back now. Separating the internal plates is strange and tricky. One of the metal tabs (discussed below), probably at top corner over the numpad, will be bent over to keep anything else from moving. Bend it back to upright with needle–nosed pliers. Stand the assembly on one end and gently tap the front plate with a hammer to slide it toward the open end of the tabs. When it lets go, it will come apart, the spring assemblies will fall out all over your work bench. If you use my layout, you will end up with one extra spring. Check to make sure that they are not bent or damaged. The key will not work properly if the spring is messed up in any way. (Model M springs might be the same, I don’t know, but the hammers are different.)

Open the case and pull all the key stems



Gently tap the plate with a hammer to slide them apart. Look for one tab that might be crimped over.
The little parts will fall out on the table when the plates come apart.



The barrels may be held in place by the mat. Be careful with the mat, since you want to re-use it if possible.



The rubber mat will probably try to stick to the front plate.



Here is the kind of mat you will wish for:



If you get one like this, treat it very carefully!



I call this side the "back plate" and it has a sliding fit with the PCB and a mylar sheet in between.


Perhaps the most fragile and difficult component is the rubber/foam mat (“mat”) that lies between the metal plate (“front plate”) and the printed circuit board (“PCB” which is affixed to another metal plate in the back). Included are photos of an immaculate mat, but your chances of getting one this nice are slim.
 
The spacebars and other long keys appear similar to the Model M spacebar, but the wire stabilizers are different (smaller diameter) and incompatible, so be very careful with them if you want to re-use them. Except for the spacebar, you can add sleeve inserts and use modern keys everywhere else, and that is probably a good idea. You can easily bend small strips of sheet metal into a “Z” shape and epoxy them down to create stabilizer tabs to accommodate the wire of a Model M spacebar, and this is probably a worthwhile mod. Just be mindful of the rather tight and critical spacing required.

Here are my sheet metal tabs, epoxied in place. The small oval holes are where the original tabs were attached.


Unfortunately, the top shell of the case is a brittle plastic and tends to break, especially in the lower corners. If the case is broken, I have had good success using “JB Weld” epoxy (automotive supplies) and embedding a reinforcing bar (a bent piece of wire, mine cut from a paper clip) in a gob of epoxy on the inside. See photos of my ghetto turnbuckle/rubber band technique to hold the sides in place until they cure. JB dries to a perfect dark gray if you are planning to paint the case that color, otherwise it is a pretty ugly repair. (I think that they use metal dust as filler.) Dupli–Color Vinyl and Fabric Coating from your local auto parts store works well and the charcoal gray color is very nice.

edit: see my later thread on another source for these cases

https://geekhack.org/index.php?topic=49313.new#new

An unbroken case - consider yourself very lucky if you get one !



Reinforced epoxy in corner with turnbuckle and rubber band for compression



A piece of wire embedded in the epoxy acts as a reinforcing bridge



Pay attention to the leg assembly if you take it apart. The sides install in mirror image.


RESTORATION  and  MODIFICATION  PROCESS :

Make mental notes or take photos of how the pieces fit together as you take it apart. These are complicated beasts, and many days may elapse between start and finish.

Clean all the parts as well as you can. I like scrubbing in warm soapy water for anything that can take it. Vacuuming is good, blowing out with compressed air, wiping it down with alcohol, at the minimum.

The first step was to clean and sand the metal plate to remove corrosion, and then paint it with Rustoleum. My first one was painted red, then green for the 2nd, then orange. Most of the photos in this wiki show the orange one. You can mask the plastic clips that hold the stabilizer wires, so that they do not get clogged with paint, giving them one very light coat of paint from the rear side at the end of the process. You can also gently push them out from behind with a small flathead screwdriver and replace them later. To do this, I put a larger flat-head screwdriver into the "mouth" of the tab and press it back into place with the shaft of the screwdriver parallel to the plate.

Stabilizer wire tabs can be removed by pushing them from the back with a small screwdriver


You will not have to worry with fabricating a new rubber pad if you were lucky enough to get a good one, but you can be comforted to know that you can make one for yourself if you have to. I have fabricated several new rubber mats using foam sheet from an art supply store (about 1/16” or 1.5mm thick). I have also used a very thin neoprene, but I think I like the art foam better. Rather than use an existing mat for a template, and risk ruining it, I taped the foam to the metal front and sprayed paint to mark the mat through the holes. It worked quite well, even though I had to use some guesswork on the fuzzy ones. Be sure to tape enough to keep it tight and flat against the plate.

Use the front plate as a template for the mat when you spray paint



5/8" holes punch with wood block behind. A good hard whack is required.





The “alignment tabs” on the plastic barrels (the little “buttress–like” appendages on the outside of the barrels) looked like a potential problem area, so I used a 5/8” hole punch instead of 1/2”, which is the actual diameter of the barrels, and offset the holes to accommodate the tabs. That seemed to work well enough. The punching was easy, since the punch was made for leather and the foam was far less tough. One good whack with a hammer, with a block of wood below, it was actually very simple and took less than 10 minutes.

Pay close attention to the spring locations. You need to set a barrel into each hole in the metal front plate, but there will be 4–5 empty barrels with no springs. In my layout, the “Right Shift”, “Backspace”, and “Numpad 0” have the same empty barrels as before. The “Enter” will need an empty barrel on the side rather than the top, and that previously empty barrel will need a spring for “Backslash/Pipe”. “Left Shift” will need an empty barrel on the right side if you want to use an ANSI–standard long one, but if you use the short 1.5x original Left Shift, you will get an “extra” 1x key for something else (eg “Windows”). See my illustration where I forgot and filled that barrel. It me over half an hour (because of at least 3 bad re–assembly attempts) to get it back together properly. If you want a tall "Numpad +" you will need to leave a space for the stabilizer.


Original setup for ISO-style spacebar etc


The left spring of the new Enter from "E" will need to be moved to "A" to accommodate Backslash and "B" and "RS" openings are OK as-is


It usually takes multiple passes through the re–assembly process to get a perfect set and fit. Even with the experience of several mods, knowing where the problems are likely to occur, I still end up putting them together and taking them apart 2–3 times every time. This is extremely frustrating and time–consuming since, in addition to the internal parts, all the key stems have to be seated to test and unseated to dis–assemble. You will probably try to take it apart with the keys in place, once, since you will not believe me when I tell you that you can’t. 

I struggled mightily with the “sliding tab force fit” or whatever they call the way these beasts are assembled, which is tedious with the original rubber mats (thin), but more difficult with a thicker, firmer new pad. On the smaller Model F XTs and ATs, with sharper curvature and tabs on the long edges only, it is not unduly difficult to put them back together if you have strong hands and fingers. However, the F–122s are much larger and broader, and include a center row of tabs in addition to the top and bottom rows. Keeping everything in place while forcing and sliding it all back together is extremely difficult and nerve–racking. I successfully accomplished it manually a couple of times, but it took inordinate time and effort.

In exasperation, after a number of successive failures, I designed a bolt–mod, having gotten excellent results from “bolt–modding” IBM Model Ms. I imagined that removing the tabs and using bolts would work here, too, and wrote the original version of this guide, but I have since changed my mind and deprecated that concept. It will work, but precise alignment of the holes is imperative. Drill your holes with the tabs firmly set in place.

I do, however, feel that a few (about 3) bolts along the longitudinal center line are helpful. Steel plates do not like inside curves, so pulling them together with inward pressure along the bend line is good. The most efficacious locations seem to be between F5 and 5%, between Enter and up arrow, and between CapsLock/Left Shift and left F6/F8. Ensure that your drill does not damage any PCB traces.

The the longest bolt lengths that fit comfortably are about M4x15 and Imperial 4-40x3/4"


I put masking tape on all the drill bit entrance and exit points, and cleaned up my holes with a file and countersink bit. Take great care here – you must be sure to drill through “clear” areas and not cut any traces embedded in the circuit board. I made that mistake once and regretted it.

Masked hole locations


I opted for readily available bolts: 4–40 x 1/2” or M4x10 with no washers (tight clearance issues) in the lower (front) side, and 4–40 x 3/4” or M4x15 with washers both sides, including rubber washers, on the upper (back) half. These are small by hardware store standards, but are not a special order item like the tiny 2mm ones you use for a Model M bolt–mod.

NOW  FOR  THE  HARD  PART !

Re–assembly is simply a matter of inserting the barrels and springs and sliding it together. Ha Ha!

I must admit that I have had to put mine together and take them back apart an average of 3 times, for various issues, almost always spring–seating related (and I am experienced at this, having taken apart and re–assembled Model Fs of all 3 types (XT, AT, and 122) many times each, and it is always frustrating). Each iteration requires removing all the key stems, sliding the plates apart, sliding them back together, and putting all the keys back on. It becomes very wearying.

Start installing barrels into the holes


There will be a few barrels that do not get spring hammers



Even I make mistakes



Ready to slide back together


Since buckling spring keyboards are assembled upside–down, with springs pointing downward, the frame must be raised off the table. I made 2 frames from scrap lumber, and they make it much easier than trying to balance the frame on books or blocks.

Wooden jig frames for IBM buckling spring keyboards



Since there are over 200 small pieces that must stay balanced in place while you wrestle and beat on the outer frame, preventing the hammer feet from jumping out of their tracks is tricky. Once the plates are pressed firmly together, they are secure, so that if you can slide the plates say, 1/3 of the way into place, then you can stand the frame upright and hammer them the rest of the way.

At first I used 2 spring clamps, 1 on each side, until I ran into a particularly difficult one



With this set of clamps (less than $30 total) it is not really very hard to make the sliding fit work


http://www.homedepot.com/p/t/100161744#.UjpD7T-ZYxI

http://www.homedepot.com/p/t/100159936#.UjpEPD-ZYxI

I have heard several people complaining that they simply could not get the internals back together, but when I asked how many clamps they were using, without exception I discovered that they were trying to do it without clamps. If you can clamp the sides together with spring clamps, then you can use the long one to pull them longitudinally. Also, there are tabs along the top and bottom, I find that I sometimes need to use my pliers to squeeze the plates together to avoid interference from the tabs. Do not despair, but plan to spend at least 20 minutes and go through multiple iterations. As always, it always takes at least twice as long the first time you do something.

After it is together, AND TESTED! the outer rows of tabs can be bent back into place, seated in their slots, and even crimped inwards a little extra, to clamp everything down nice and snug.

Make sure before you assemble everything!


My recommendation is to test your assembly at every opportunity. For example, as soon as you have the plates together, test the springs. If even one of them is not seated properly, you will be taking it apart again.

I have tried various sound–dampening techniques. I have sprayed the bottom of the case with black rubber “paint” (not much help) and cut a piece of black felt (good) or waffle rubber (better) to fit. I edged all the parts that fit together with black electrical “friction” tape, the fabric kind that is not very sticky (over time it will leave a sticky residue, however). I stuffed extra padding into the bottom section to deaden the sound somewhat, and I flossed the springs. These modifications cut down dramatically on the resonance and higher overtones, making it much more pleasant for myself and my family.

Sound insulation is very important to some people


Dental floss for mod


The floss needs to be almost as long as the spring - and certainly more than half




Although I am rather lukewarm on the floss mod for the Model M, I think that it is much better and more desirable on the Model F. I have a family who sleeps within earshot of my keyboard, so the floss mod is a necessity at my house. However, if you like the singing harmonic overtones of going bareback on steel, keep it stock.

« Last Edit: Fri, 17 May 2019, 19:16:57 by fohat.digs »
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Offline SpAmRaY

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Re: IBM Model F-122 modification - Harry's ANSI modification - revised
« Reply #1 on: Fri, 20 September 2013, 10:44:49 »
Awesome write up fohat!!

Offline fohat.digs

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Re: IBM Model F-122 modification - Harry's ANSI modification - revised
« Reply #2 on: Fri, 20 September 2013, 10:59:13 »
This is a "new improved" version of my previous guide, which had a lot of things that I was not happy with.

Most importantly, I want to forever retract my recommendation to cut off the alignment tabs on the front plate. It "can" work fine the way I described before, but there is too much margin for error. And it is a destructive and non-reversible change.

With all the original tabs in place, PLUS a few extra bolts to snug it up down the middle, you get the best of both worlds. But buy some carpentry clamps, they will save you a bunch of heartache.
« Last Edit: Sat, 21 September 2013, 12:54:49 by fohat.digs »
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Re: IBM Model F-122 modification - Harry's ANSI modification - revised
« Reply #3 on: Fri, 20 September 2013, 11:43:28 »
The upload tool on the site doesn't work very well. This isn't the first time I've seen people having issues. I actually never bother with the site upload because of this problem. Perhaps you can try using imgur?

If you don't want to upload pictures to imgur yourself, I could upload pictures for you and PM you all the links.

Offline fohat.digs

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Re: IBM Model F-122 modification - Harry's ANSI modification - revised
« Reply #4 on: Fri, 20 September 2013, 12:14:55 »
The upload tool on the site doesn't work very well. This isn't the first time I've seen people having issues. I actually never bother with the site upload because of this problem. Perhaps you can try using imgur?

If you don't want to upload pictures to imgur yourself, I could upload pictures for you and PM you all the links.

I changed the photos and linked them to Imgur. It seemed to work well, but I prefer "local" to the cloud.

Also, I am hoping that this thread can morph into a legitimate wiki guide someday, so I was hoping that it could all be contained within Geekhack itself.

PS - I recently added another guide for a "stealth" version of this keyboard - all black and no shell case - check it out
« Last Edit: Sun, 22 September 2013, 12:12:18 by fohat.digs »
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Re: IBM Model F-122 modification - Harry's ANSI modification - revised
« Reply #5 on: Fri, 20 September 2013, 12:22:59 »
The new Wiki will allow us to port things over from current threads. If you want this added, I can help move it to the Wiki when we finally get the update. But the new Wiki will be based on BBcode and open to everyone, regardless of a Wiki account, so you could also make a thread inside the new Wiki. The way I understand it, it will look like a sub-forum like we currently have.

As for the pictures themselves? I'm not sure what the best way to handle that is. Maybe just imgur for now and I can ask around to see what the best method is?

Also before I forget, thanks for making this guide. I've referred people to it before and I'm glad you decided to work on it :D.
« Last Edit: Fri, 20 September 2013, 12:28:07 by CPTBadAss »

Offline berserkfan

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Re: IBM Model F-122 modification - Harry's ANSI modification - revised
« Reply #6 on: Fri, 20 September 2013, 12:27:09 »
just wanted to say that I agree with Harry 100%! And yes, if you haven't tried and succeeded in putting an F 83 back together, I suggest you skip tackling the F122s. Don't be too ambitious or you will have a thread here asking for help!
Most of the modding can be done on your own once you break through the psychological barriers.

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Re: IBM Model F-122 modification - Harry's ANSI modification - revised
« Reply #7 on: Fri, 20 September 2013, 19:08:56 »
I will admit to not having used clamps to try and reassemble mine (and failed)

I'm currently looking to borrow some from work, but I forget them last time I was there. I might just go buy some. Like many others, I was bolstered by the relative ease in taking apart and reassembling F XT's, model C keyboards, and 4704 keyboards.

Thanks for updating the guide!

Offline YakMN

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification - revised
« Reply #8 on: Fri, 20 September 2013, 21:35:49 »
Great writeup Harry!

The old one, and this new one, always leave me with mixed emotions.... I had fun with the AT F, and I'd like a full blown 122 key F, but man that assembly sounds brutal.

If you push the stabilizer guides through, later, when putting it back together, do you have to hit them with a hot knife or anything to mushroom them out enough so they stay in place?

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification - revised
« Reply #9 on: Sat, 21 September 2013, 07:44:20 »
<< Since there are over 200 small pieces that must stay balanced in place while you wrestle and beat on the outer frame, preventing the hammer feet from jumping out of their tracks is tricky. Once the plates are pressed firmly together, they are secure, so that if you can slide the plates say, 1/3 of the way into place, then you can stand the frame upright and hammer them the rest of the way.  >>

I just opened an F XT a few days ago, to adjust the space bar tension. I'm citing from Harrry's writing, for this was the only delicate part: separating and reattaching the plates.
The difference was that I kept the keyboard upside-down horizontally, using two piles of books on each side. I used a hammer to separate the plates and put them back. I hammered one side, holding a small piece of 2x4 against the other side.
When I reattached the plates, I used a knife to hold down the hammer for spacebar in its track, until the plates where joined together. I didn't need the clamps. It worked at the first try. Some people used a floss to hold it down.
I did it the same way for F AT.
It is a delicate operation, for you can break the hammers if they jump from the tracks and they can damage the PCB. I saw it happened, not with my keyboard, though.

« Last Edit: Sun, 22 September 2013, 15:34:32 by poxeclipse »

Offline fohat.digs

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification - revised
« Reply #10 on: Sat, 21 September 2013, 09:20:51 »
I didn't need the clamps. It work at the first try.

You never can tell. They are all different.

I did 4-5 XTs and 3-4 ATs a few years ago, all by hand, without clamps. I am not sure that I ever got one to work on the first try, but it was not overly difficult. After some frustration with the spacebar "undercarriages" I started using a thread wrapped around it with a weight hanging off the edge of the workbench, which I later removed.

And, I did a big F-122 the first couple of times by hand, but I was very lucky, in retrospect. Later, and especially when I started using nice thick pads that I cut myself, I decided that it was not worth the heartache and bought clamps.

Since there are multiple stiff plates that need to nest perfectly, sometimes they get a bit "sprung" and don't want to mate up so smoothly. That is also the reason that I use a couple of bolts down the valley line.

I have done about half a dozen F-122s, with at least 2-3 iterations on each, so I have had a variety of experiences.

And, I did one about a month ago that was dramatically harder than any one I had done before (when I went to 4 clamps instead of 2) but your guess is as good as mine as to the reasons that this one did not want to go back together.
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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #11 on: Sun, 22 September 2013, 14:13:34 »
I've done my XT three times, as well as a model C and a 50-key 4704-100 keyboard, all by hand, without clamps, first try with no issue. The 122 I have never gotten back together (except when I remove the replacement foam completely). Of course, my 122 is slightly "sprung", with the plates having slightly different curvature radii.

I'm now waiting on some clamps to arrive. I hope they will work out for me.

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #12 on: Fri, 11 October 2013, 07:10:20 »
@fohat.digs

Thank you for the guide!  I never would have started refurbishing my F AT without it.  It is in progress now.  Had a rusty plate that vinegar took care of.  Going to need to replace the mat.  Got clamps at the ready too.
« Last Edit: Fri, 11 October 2013, 07:12:13 by Game Theory »
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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #13 on: Sun, 17 November 2013, 20:22:43 »
Finished up my F AT and I cannot emphasis how important the clamp were.  Due to over paint coating on my part the long clamp was a necessity to get the plate and pcb back together.

I used a piece of silicone to replace the mat.  Seemed to work well enough but time will tell.
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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #14 on: Wed, 21 May 2014, 18:42:26 »
I have taken a few questions recently on the subject of stabilizer inserts in barrels and realized that I did not address that issue directly in the original guide.

Your new keys are almost certain to come with "peg-leg" stabilizers instead of the original wires. The spacebar is a special case, and I discussed it on its own.

Otherwise, there are 5 long "horizontal" keys: Backspace, Enter, Right Shift, Left Shift, and numpad "0"

and 2 "vertical" keys: numpad Enter and numpad +

There are 2 types of barrel inserts: one for the horizontal keys, which have the hole in the center,

and one for the vertical keys, in which the hole is off-center. See the photos below.

Both types need to be inserted into the barrel in a vertical orientation, where the thicker walls of the insert are at the tops and bottoms of the barrels, and there is a bit of open space on each side. Additionally, the off-center ones need to be inserted so that the larger "head" portion is at the top, as shown.

If the plates are apart, they can be pushed in and out with a finger. If you don't want to take the internals apart, the inserts can be fished out (they are tight) but be careful not to abrade the inner surface of the hole, because this can create friction on the "peg-leg" so don't just stick one side of your needle-nose pliers in, squeeze, and yank.

I have been successful by straightening a paper clip (the thin ones) and bending a tiny hook in the end of it.
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Offline fohat.digs

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #15 on: Thu, 05 February 2015, 07:49:57 »
If you are thinking of making this modification, you owe it to yourself to look at this beautiful guide:

http://deskthority.net/workshop-f7/ibm-terminal-es-to-us-iso-lot-of-pictures-t9745.html
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Offline rowdy

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #16 on: Thu, 05 February 2015, 15:20:56 »
Thanks for that link!

Although I'm trying to downsize, I'm still curious about an F122.  Maybe one day.  I'll have to try to remember where to find this thread, and the one you just linked, for future reference.
"Because keyboards are accessories to PC makers, they focus on minimizing the manufacturing costs. But that’s incorrect. It’s in HHKB’s slogan, but when America’s cowboys were in the middle of a trip and their horse died, they would leave the horse there. But even if they were in the middle of a desert, they would take their saddle with them. The horse was a consumable good, but the saddle was an interface that their bodies had gotten used to. In the same vein, PCs are consumable goods, while keyboards are important interfaces." - Eiiti Wada

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Offline fohat.digs

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #17 on: Tue, 29 September 2015, 09:15:23 »
I need to add this so that I can find it:

https://geekhack.org/index.php?topic=45089.msg939658#msg939658

If you have a 1st-generation M-122 case, it is much simpler with far less cuts to be made.
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Offline fohat.digs

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #18 on: Sun, 08 November 2015, 13:30:33 »
Earlier in the guide I showed my replacement tabs to allow the use of Model M spacebars with their much thicker wires. The bent sheet metal tabs have worked well enough in general, and in fact have the advantage of being able to be bent and "tuned" but they are not perfect.

This post from yesterday showed my attempt to bend nice copper wires into tabs, but they just didn't work out because the clearances were too tight between key caps and between the bottom skirt of keys and the front plate. Therefore, I have gone back to my original use of bent sheet metal.



But since I do try to contribute, my last F-122 came with a broken case (as often happens) in the thin area below the numpad. After an epoxy repair, I decided to try something different from the charcoal gray "Dupli-Color" that I have been so fond of in the past. Naturally, I would have like to match the IBM "industrial" tone, but I have not yet found it.

Rustoleum's new line of "hammered metal" paints are wonderful, so after priming the top shell I gave it 2 good coats of Rustoleum "Rosemary". Results are below:






« Last Edit: Tue, 10 November 2015, 13:46:07 by fohat.digs »
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Offline megahertzcoil

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #19 on: Tue, 10 November 2015, 09:39:41 »
Thanks for this thread.  I am about to start on a Model F AT ANSI conversion that has a well used/loved past.  The paint on the top cover has started to wear off where in the wrist area and I am thinking about refinishing it.  What did you use to paint the keyboard in last picture of your first post?  If I do refinish the top cover, I want to chose a paint that will adhere well to the plastic.  I am not worried about matching the original color.

Offline fohat.digs

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #20 on: Tue, 10 November 2015, 09:57:12 »

The paint on the top cover has started to wear off where in the wrist area and I am thinking about refinishing it. 
What did you use to paint the keyboard in last picture of your first post?


I think of the outer surface of the Model F case as more like a "skin" than a coat of paint, it has a distinct thickness.

I have had excellent results with "Dupli-Color" which is marketed as a "coating" in automotive stores and is made to hold up well on plastic.
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Offline megahertzcoil

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #21 on: Sat, 14 November 2015, 18:39:57 »
Thanks for the info!  I will look into those products. 

Offline Venatorious

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #22 on: Mon, 25 January 2016, 23:26:51 »
Just having done a floss mod on my F, I was wondering how you cut your floss to the desired length.

Also, could you give more insight on why you think adding bolts is necessary? I only ask because I will be working with my unsaver soon, and am debating on doing this to it. 

I find myself coming back to this guide every time I have a need to mod something on my F122.   Legendary guide Fohat!  :thumb:

Offline jacobolus

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #23 on: Mon, 25 January 2016, 23:59:24 »
Easiest way to cut floss is to stick the whole piece of floss into the spring, and then snip it flush with the top with some flush cutters.

Adding bolts helps if you get uneven feel across the board due to differing spacing between the plates in different places. If you have bolts you can adjust the tension at different spots until everything is consistent and matches your preference.

Offline khronokrator

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #24 on: Fri, 20 October 2017, 15:19:45 »
Just a slight bump/review for an old topic - having recently bought an F-122 from fohat that was restored and carefully modified in the manner of his guide, I feel I can offer some perspective coming from someone who had only used stock Model Fs in varying conditions up until this point.

(The funny thing is that I'd actually seen this guide eons ago, but I knew my own technical skills weren't up to the task and that I'd have to stick with stock and simply try to find the best condition boards available.)

To me, the most striking difference of these mods is indeed the sound profile of the keys. The Model F produces a rather distinctive high-pitched 'ping' that I think chyros once compared to the staccato sound of machine-gun fire in one of his earlier videos. While I don't dislike it, it definitely carries through a home or office and can be a serious distraction for other people if noise is an issue. The sound proofing and floss modding really do change the sound profile in a significant way, one that (to my mind) feels a bit more quintessentially 1980s - like the early Model M or clicky Alps switches. It does sound a bit closer to the Model M, but definitely more metallic in nature - like bolts being driven into steel. The Model M still sounds thicker (or 'thockier' if you will) due to the different mechanism and proportionally larger amount of plastics involved.

It's probably something that's difficult to capture on camera without a high quality microphone, because lot of the typing comparisons you see on Youtube simply don't do it justice.

Now, on to the actual tactile response of a Model F - I'm not particularly good at describing a very subjective experience such as tactility, but I think fohat's board has perhaps the 'tightest' and sharpest tactile feedback of any Model F I've yet encountered. It definitely feels sharper and perhaps just a tad heavier than my older Model Fs, but I found the experience not unpleasant at all; now that I've gotten used to it I think my now-second best F-122 feels a bit too loose and wobbly. I remember that chyros has discussed 'key wobble' before in his videos, and here on fohat's board it's absolutely rock solid - quite comparable to NMB space invaders in its stability. There's just absolutely no key wobble at all; even my NIB 1390131 Model M feels shockingly loose in comparison.

Now, I've had a few experiences with F-122s before, although most of my familiarity with buckling springs is with the Model M. The first F-122 I'd ever bought turned out to have quite a bit of corrosion on the mounting plate, and once I opened it up I discovered the springs themselves were corroded. Ironically this produced a more satisfying tactile feedback (and slightly dampened pinginess) than my second F-122, though it can't have been good for the board's longevity. My second board was in better condition overall, but the foam padding was degrading and several keys didn't work. Comparatively, I've used buckling springs for longer and continue to do so even at work, as we still use the old AS/400 system for inventory and the terminals often use Unicomp Model Ms - though they're often so heavily used they actually feel closer to the Model F, even with their insides totally caked with junk.

All told, this is probably the most satisfying typing experience I've had out of a Model F, and fohat's board is probably now in my top 3 keyboards list. I feel I'm going to be using it for many years.

Offline rowdy

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #25 on: Sun, 22 October 2017, 20:44:44 »
Based on that review, fohat could set himself up a small business refurbishing Model F keyboards! ;)
"Because keyboards are accessories to PC makers, they focus on minimizing the manufacturing costs. But that’s incorrect. It’s in HHKB’s slogan, but when America’s cowboys were in the middle of a trip and their horse died, they would leave the horse there. But even if they were in the middle of a desert, they would take their saddle with them. The horse was a consumable good, but the saddle was an interface that their bodies had gotten used to. In the same vein, PCs are consumable goods, while keyboards are important interfaces." - Eiiti Wada

NEC APC-H4100E | Ducky DK9008 Shine MX blue LED red | Ducky DK9008 Shine MX blue LED green | Link 900243-08 | CM QFR MX black | KeyCool 87 white MX reds | HHKB 2 Pro | Model M 02-Mar-1993 | Model M 29-Nov-1995 | CM Trigger (broken) | CM QFS MX green | Ducky DK9087 Shine 3 TKL Yellow Edition MX black | Lexmark SSK 21-Apr-1994 | IBM SSK 13-Oct-1987 | CODE TKL MX clear | Model M 122 01-Jun-1988

Ị̸͚̯̲́ͤ̃͑̇̑ͯ̊̂͟ͅs̞͚̩͉̝̪̲͗͊ͪ̽̚̚ ̭̦͖͕̑́͌ͬͩ͟t̷̻͔̙̑͟h̹̠̼͋ͤ͋i̤̜̣̦̱̫͈͔̞ͭ͑ͥ̌̔s̬͔͎̍̈ͥͫ̐̾ͣ̔̇͘ͅ ̩̘̼͆̐̕e̞̰͓̲̺̎͐̏ͬ̓̅̾͠͝ͅv̶̰͕̱̞̥̍ͣ̄̕e͕͙͖̬̜͓͎̤̊ͭ͐͝ṇ̰͎̱̤̟̭ͫ͌̌͢͠ͅ ̳̥̦ͮ̐ͤ̎̊ͣ͡͡n̤̜̙̺̪̒͜e̶̻̦̿ͮ̂̀c̝̘̝͖̠̖͐ͨͪ̈̐͌ͩ̀e̷̥͇̋ͦs̢̡̤ͤͤͯ͜s͈̠̉̑͘a̱͕̗͖̳̥̺ͬͦͧ͆̌̑͡r̶̟̖̈͘ỷ̮̦̩͙͔ͫ̾ͬ̔ͬͮ̌?̵̘͇͔͙ͥͪ͞ͅ

Offline khronokrator

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Re: IBM Model F-122 terminal keyboard - Harry's ANSI modification
« Reply #26 on: Tue, 31 October 2017, 01:09:55 »
Honestly, he really could. He does great work and his keyboard is probably the favorite in my collection right now, even over my mint condition Omnikeys.

I mean no offense to Ellipse or to put a disservice upon his incredible work for the community, but I see no reason to go for a Kishaver when a modded F-122 is pretty much all I could ask for or want in a keyboard.