FSSK v1.00 - Installation & Users Manual
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
I will post here the installation and users manual for the FSSK v1.00
Attached you can find the source files:
Here you can find a configuration file with no keys set-up that could be used for testing: This is the file that I am using with the connector in the middle. Cables are swapped in pairs. And this is the file that lot_lizard created with an straight cable: Attached the source files for the FEXT. Do not hesitate to as questions.
Attached you can find the source files:
Here you can find a configuration file with no keys set-up that could be used for testing: This is the file that I am using with the connector in the middle. Cables are swapped in pairs. And this is the file that lot_lizard created with an straight cable: Attached the source files for the FEXT. Do not hesitate to as questions.
- Attachments
-
- FEXT_v1.0b.zip
- (3.39 MiB) Downloaded 590 times
Last edited by idollar on 26 May 2016, 22:36, edited 7 times in total.
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
Soldering the PCB
The cable that I have used is an IDE cable The individual cables shall be separated in the ribbon The following picture shows the length of the cable The distribution of cables in the PCB pads is as follows: Therefore the ribbon cable shall be divided as follows.
Notice above that there are 10 cables to many in the ribbon. I have left then in the middle grounded. I have passed the cables through the PCB, as shown in the following. I start soldering the extremes, on the PCB TOP. This fixes the ribbon to the PCB while soldering. Following the result of the cable + PCB. Note that I have left the middle open. To make sure that I do not miss any cable, I start from the left to the middle. I then did right to the middle. Note also that I have soldered the the two extreme cables to the middle GND. I join the left cables in the middle. And isolate them: There is no picture, but these middle cables are also soldered to the middle GNDs.
I scratched each sensing pad to test continuity. There is no need to do that. I did it just to test the design.
The cable that I have used is an IDE cable The individual cables shall be separated in the ribbon The following picture shows the length of the cable The distribution of cables in the PCB pads is as follows: Therefore the ribbon cable shall be divided as follows.
Notice above that there are 10 cables to many in the ribbon. I have left then in the middle grounded. I have passed the cables through the PCB, as shown in the following. I start soldering the extremes, on the PCB TOP. This fixes the ribbon to the PCB while soldering. Following the result of the cable + PCB. Note that I have left the middle open. To make sure that I do not miss any cable, I start from the left to the middle. I then did right to the middle. Note also that I have soldered the the two extreme cables to the middle GND. I join the left cables in the middle. And isolate them: There is no picture, but these middle cables are also soldered to the middle GNDs.
I scratched each sensing pad to test continuity. There is no need to do that. I did it just to test the design.
Last edited by idollar on 17 Apr 2016, 13:44, edited 4 times in total.
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
Curving PCB
The PCB shall be curved to match the curved shape of the SSK.
To do it, I applied heat with a powerful hairdryer, curve it more than what is actually needed and let it cold down.
Here are pictures of the process.
This is what is needed. PCB, some tape, paper (or whatever), and the hairdryer. I heated the PCB first I forced the PCB curved (once heated) and hold it with tape: I heated the PCB again, with the tape in. And let it cold down while preparing for the next step:
The PCB shall be curved to match the curved shape of the SSK.
To do it, I applied heat with a powerful hairdryer, curve it more than what is actually needed and let it cold down.
Here are pictures of the process.
This is what is needed. PCB, some tape, paper (or whatever), and the hairdryer. I heated the PCB first I forced the PCB curved (once heated) and hold it with tape: I heated the PCB again, with the tape in. And let it cold down while preparing for the next step:
Last edited by idollar on 17 Apr 2016, 13:54, edited 1 time in total.
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
Opening the SSK and finalising the PCB curving
This is the initial setup and tools:
Standard process:
My key-puller is a cappuccino spoon, which I use to puss the keys from below.
My SSK was already screw-modded. So I simply open it:
Now is time to check the PCB curving process:
Just perfect
This is the initial setup and tools:
Standard process:
My key-puller is a cappuccino spoon, which I use to puss the keys from below.
My SSK was already screw-modded. So I simply open it:
Now is time to check the PCB curving process:
Just perfect

Last edited by idollar on 17 Apr 2016, 14:13, edited 1 time in total.
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
Making sure that the flippers fit
The version of the SSK, requires some modding of the plate to allow the bigger F flippers to fit.
First we keep the original M flippers save in their bag.
This is where the problem starts. The channels present in the modern Ms to let liquids to go through and some other bits are fine with smaller flippers, but too big for the larger Ms.
The smaller parts are easy to remove:
With the same cutter and lot of care, one can remove the channel: The final work is done with sand paper:
This solves the issue:
The version of the SSK, requires some modding of the plate to allow the bigger F flippers to fit.
First we keep the original M flippers save in their bag.
This is where the problem starts. The channels present in the modern Ms to let liquids to go through and some other bits are fine with smaller flippers, but too big for the larger Ms.
The smaller parts are easy to remove:
With the same cutter and lot of care, one can remove the channel: The final work is done with sand paper:
This solves the issue:
Last edited by idollar on 17 Apr 2016, 14:45, edited 2 times in total.
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
Installing the PCB
Get the flippers in their place:
THIS IS SHALL NOT BE DONE
With the FSSK 0001 I used original the rubber mat between the flippers and the PCB.
I tried to do the same thing with the FSSK 0003 in this post. It took me some 10/15 attempts to realise that the mat does not allows the flippers to flip properly. In my particular case, the spacebar flipper would not flip completely, leading to a lower threshold. The solution was as simple as removing the mat ... after 5 hours of test/error ...
I repeat: do not use the rubber mat. This picture is only here to explain the mistake that I made
Install the PCB:
Isolate the metal plate with tape and put it in place:
Before installing all the screws, I suggest to do just these and test the result.
Believe me, if you have to troubleshoot the board, you will hate those screws.
And place the caps back:
Get the flippers in their place:
THIS IS SHALL NOT BE DONE
With the FSSK 0001 I used original the rubber mat between the flippers and the PCB.
I tried to do the same thing with the FSSK 0003 in this post. It took me some 10/15 attempts to realise that the mat does not allows the flippers to flip properly. In my particular case, the spacebar flipper would not flip completely, leading to a lower threshold. The solution was as simple as removing the mat ... after 5 hours of test/error ...
I repeat: do not use the rubber mat. This picture is only here to explain the mistake that I made
Install the PCB:
Isolate the metal plate with tape and put it in place:
Before installing all the screws, I suggest to do just these and test the result.
Believe me, if you have to troubleshoot the board, you will hate those screws.
And place the caps back:
Last edited by idollar on 20 Apr 2016, 02:16, edited 1 time in total.
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
Soldering the controller
the pictures are self explanatory (I hope):
Soldering on the top layer may be difficult because of the proximity of the components.
I recommend to use the bottom side only:
Start with the extremes to fix the ribbon cable:
the pictures are self explanatory (I hope):
Soldering on the top layer may be difficult because of the proximity of the components.
I recommend to use the bottom side only:
Start with the extremes to fix the ribbon cable:
Last edited by idollar on 20 Apr 2016, 02:23, edited 1 time in total.
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
Soldering the controller
This is the technique that I used to ensure proper grounding.
Find a screw that fits in diameter and length. I honestly do not know the size that I have used. I used the one that fit better from my pool of spares.
Using a FLEXIBLE DOUBLE cable, I twisted it around the screw.
And add Tin to it. This makes it rigid.
Sorry, the pictures are not good
And do the same with the other side.
Simple, isn't it ?
This is the technique that I used to ensure proper grounding.
Find a screw that fits in diameter and length. I honestly do not know the size that I have used. I used the one that fit better from my pool of spares.
Using a FLEXIBLE DOUBLE cable, I twisted it around the screw.
And add Tin to it. This makes it rigid.
Sorry, the pictures are not good

And do the same with the other side.
Simple, isn't it ?
Last edited by idollar on 21 Apr 2016, 00:28, edited 1 time in total.
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
Hello,
It is time to update the post
Since the FSSK v1.00 was created, the QMK and VIAL firmware were developed.
Purdea Andrei ported the firmware to the xwhatsit controller, meaning that:
1.- The initial problems in having a single threadshold to sense the keys has completely dissapeared by using the new method.
2.- It is possible to create macros. Many other features are available.
3.- With VIAL these macros and "tap dance" can be configured on the fly using their application.
The xwhasit controller has limited memory. In order to make VIAL work the number of layers and "tap dance"s need to be limited in number. This is not a big deal for me.
in this (viewtopic.php?p=519951#p519951) post I have posted the compiled binaries that should work with the FSSK v1.00.
I attach the files to this post also for completeness.
Cheers
i$
It is time to update the post

Since the FSSK v1.00 was created, the QMK and VIAL firmware were developed.
Purdea Andrei ported the firmware to the xwhatsit controller, meaning that:
1.- The initial problems in having a single threadshold to sense the keys has completely dissapeared by using the new method.
2.- It is possible to create macros. Many other features are available.
3.- With VIAL these macros and "tap dance" can be configured on the fly using their application.
The xwhasit controller has limited memory. In order to make VIAL work the number of layers and "tap dance"s need to be limited in number. This is not a big deal for me.
in this (viewtopic.php?p=519951#p519951) post I have posted the compiled binaries that should work with the FSSK v1.00.
I attach the files to this post also for completeness.
Cheers
i$
- Attachments
-
- vial_firmware_for_original_FSSK_V1.00.tar
- (140 KiB) Downloaded 83 times
Last edited by idollar on 06 Jul 2024, 19:36, edited 1 time in total.
- shreebles
- Finally 60%
- Location: Cologne, Germany
- Main keyboard: FaceW 45g Silent Red /NerD60 MX Red
- Main mouse: Logitech G303 / GPro (home) MX Anywhere 2 (work)
- Favorite switch: Silent Red, Old Browns, Buckling Spring,
- DT Pro Member: 0094
Amazing stuff, I$. Thank you for the tutorials, your idea and all the work you did on this project.
After postponing it for so long, it was finally FSSK building time today
Following your advice from the other thread, I did not use the mat.
I have the IDE ribbon cable ready, all it needs now is a controller.
I wonder, do you think I can solder the cable to the holes without taking it all apart again? Maybe by bending the top part after heating it again so that I can reach both sides of the holes?
Anyway, I did a test run without a controller and it clicks 99% fine. There is one key that feels slightly rough/scratchy and one key that is a bit harder to press than the others, wobbly. I believe this is due to there being very few screws under that position to hold the flipper in place (it's the L key, turn it around and you will barely find any screws there).
Or maybe it is due to this beat up and glued barrel frame as you can see, it's just not as solid as a new one.
The feeling is amazing. Exactly what membrane IBM keyboards are lacking: Smoother, lighter keys and a sharper click.
But the sound... Oh my
That thing is beyond loud. Just like the SSK phosphorglow posted two years ago (the video is gone now) this little SSK has no rubber mat to dampen its sounds. And the flippers are larger and they snap right on the plastic of the PCB, instead of three sheets of membranes.
I'm not sure if I, my girl or my neighbors could ever get used to that sound. It's intense.
I do hope that I did everything right by leaving out the rubber mat? And not using any tape or other to isolate the PCB or the metal plate? As in the other thread, you said no isolation is needed...?
After postponing it for so long, it was finally FSSK building time today

Following your advice from the other thread, I did not use the mat.
I have the IDE ribbon cable ready, all it needs now is a controller.
I wonder, do you think I can solder the cable to the holes without taking it all apart again? Maybe by bending the top part after heating it again so that I can reach both sides of the holes?
Anyway, I did a test run without a controller and it clicks 99% fine. There is one key that feels slightly rough/scratchy and one key that is a bit harder to press than the others, wobbly. I believe this is due to there being very few screws under that position to hold the flipper in place (it's the L key, turn it around and you will barely find any screws there).
Or maybe it is due to this beat up and glued barrel frame as you can see, it's just not as solid as a new one.
The feeling is amazing. Exactly what membrane IBM keyboards are lacking: Smoother, lighter keys and a sharper click.
But the sound... Oh my

That thing is beyond loud. Just like the SSK phosphorglow posted two years ago (the video is gone now) this little SSK has no rubber mat to dampen its sounds. And the flippers are larger and they snap right on the plastic of the PCB, instead of three sheets of membranes.
I'm not sure if I, my girl or my neighbors could ever get used to that sound. It's intense.
I do hope that I did everything right by leaving out the rubber mat? And not using any tape or other to isolate the PCB or the metal plate? As in the other thread, you said no isolation is needed...?
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
thanks to you guys. I am the one that is having fun doing it

Good !!
After postponing it for so long, it was finally FSSK building time today
You can definitely do it. It is not a must to use the technique that I have used. You can always try to solder them from the top, without going though the pad-hole. This is what XMIT tried.
I wonder, do you think I can solder the cable to the holes without taking it all apart again? Maybe by bending the top part after heating it again so that I can reach both sides of the holes?
It is lower with the mat on. Try it. It may work as it did with the FSSK 0001.Anyway, I did a test run without a controller and it clicks 99% fine. There is one key that feels slightly rough/scratchy and one key that is a bit harder to press than the others, wobbly. I believe this is due to there being very few screws under that position to hold the flipper in place (it's the L key, turn it around and you will barely find any screws there).
Or maybe it is due to this beat up and glued barrel frame as you can see, it's just not as solid as a new one.
The feeling is amazing. Exactly what membrane IBM keyboards are lacking: Smoother, lighter keys and a sharper click.
But the sound... Oh my![]()
That thing is beyond loud. Just like the SSK phosphorglow posted two years ago (the video is gone now) this little SSK has no rubber mat to dampen its sounds. And the flippers are larger and they snap right on the plastic of the PCB, instead of three sheets of membranes.
I am also thinking of using a different material, glued to the PCB, that wouldn't block the flipping of the flippers.
I will test it.
BTW: I have more pictures to post, including my technique to solder the ribbon to the controller
- shreebles
- Finally 60%
- Location: Cologne, Germany
- Main keyboard: FaceW 45g Silent Red /NerD60 MX Red
- Main mouse: Logitech G303 / GPro (home) MX Anywhere 2 (work)
- Favorite switch: Silent Red, Old Browns, Buckling Spring,
- DT Pro Member: 0094
Awesome! Thanks for the quick reply.
I will take it apart soon and try it with the mat. Since it is a prototype PCB it might work with the mat, as yours did.
Also I hope that it will reduce the distance between the PCB and the flippers which should tighten the whole assembly somewhat. I might reinforce the glue again as I suspect it might not be solid enough.
Since I will take it apart anyway, I will take a closer look at soldering through-hole vs. on-top.
I will take it apart soon and try it with the mat. Since it is a prototype PCB it might work with the mat, as yours did.
Also I hope that it will reduce the distance between the PCB and the flippers which should tighten the whole assembly somewhat. I might reinforce the glue again as I suspect it might not be solid enough.
Since I will take it apart anyway, I will take a closer look at soldering through-hole vs. on-top.
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
I tried both ways with the FSSK 0001 and it worked
I think that it has to do with the barrel plate actually and how the mat fits it. If it is somehow folded, even a little bit, it would not let the flippers go.
I am thinking that perhaps one could add something in the middle that glued to the PCB and used the mat under the PCB, between the PCB and the metal plate.
In this way the flippers would not hit the PCB directly (less noise) and the PCB would not transmit the pressure to the metal plate (more noise). I can test all these combinations and record the result.
BTW ... the sound difference with and without mate was already recorded and posted ....
I think that it has to do with the barrel plate actually and how the mat fits it. If it is somehow folded, even a little bit, it would not let the flippers go.
I am thinking that perhaps one could add something in the middle that glued to the PCB and used the mat under the PCB, between the PCB and the metal plate.
In this way the flippers would not hit the PCB directly (less noise) and the PCB would not transmit the pressure to the metal plate (more noise). I can test all these combinations and record the result.
BTW ... the sound difference with and without mate was already recorded and posted ....
- lot_lizard
- Location: Minnesota
- Main keyboard: Indy SSK Model MF
- Main mouse: Logitech Anywhere MX
- Favorite switch: Beamspring
- DT Pro Member: -
You could maybe try the replacement "blanket" from Unicomp. I personally prefer it to the rubber mat, and have it in a couple SSKs (keeping the original for posterity). It is white and thinner, or gives that impression when handling. It is a "one size fits all" for the M, so you would just trim off the ten key portion. I was planning on using for my FSSK builds from the start
EDIT:. It is a mystery to find on the site btw. This is from my notes:
http://www.pckeyboard.com/page/product/MEM
"Blanket part number 1403033" in the part number field
EDIT:. It is a mystery to find on the site btw. This is from my notes:
http://www.pckeyboard.com/page/product/MEM
"Blanket part number 1403033" in the part number field
- idollar
- i$
- Location: Germany (Frankfurt area)
- Main keyboard: IBM F or M
- Favorite switch: BS
- DT Pro Member: -
I was thinking of trying the same thin foam that I used with the F77: workshop-f7/ibm-107-472x-41-53951-lot-o ... ml#p220169
It is thin, will not get off the PCB and will mute the flippers.
It is thin, will not get off the PCB and will mute the flippers.
- Khers
- ⧓
- Location: Sweden
- Main keyboard: LZ CLSh
- Main mouse: Logitech MX Ergo
- Favorite switch: Buckling Springs | Topre | Nixdorf Black
- DT Pro Member: 0087
The documentation in this manual is top notch! Very nice photos i$! Speaking of the photos though, they are very dim on my ipad, but look nice when I'm on my mac. Weird.