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Model F keyboard to Model M Keyboard

What do you mean? Do you mean make the model F AT compatible? There are some rare (these days) model F that shipped with the early 5170 that are AT compatible. Keyboard layout is slightly different.
 
If you're talking about replacing the Model F's buckling spring capacitance switches with the Model M's buckling spring membrane switches, I'd argue that the Model F mechanism is superior.

There are two different Model Fs. The earlier is the "Model F" (aka "Model F-XT"). It is an XT keyboard electrically, and will not work with an AT or PS/2 keyboard interface without a converter. You can make an XT to USB keyboard converter with a cheap atmega32u4 unit as detailed here: tmk_keyboard/converter/ibmpc_usb at master · tmk/tmk_keyboard · GitHub

The layout of the F-XT is pretty awful. I like the key action, but I hate the layout.

The Model F-AT will work out of the box with, well, an AT. It will also work on a PS/2 keyboard port with a simple DIN5 to PS/2 adapter cable. You can also convert it to USB with a different adapter that you can find in the same github as the above adapter.

The F-AT layout is better than the F-XT, but it still has a funky arrangement of Backspace, Backslash, and Enter. However, even though the F-AT doesn't have removable keycaps like the Model M, the key stems themselves are exactly the same. You can take apart an F-AT, move some of the capacitive flipper things around into a Model M layout (there are unused pads on the board and holes in the metal frame that match the Model M layout), put it back together, and substitute those three keys off a Model M, and have your proper ISO layout. IIRC backspace is the only one that needs moved, but I can't remember for sure.

However, in this configuration it will not send the correct scancodes for the keys you moved around. This can be corrected by making your own keymap for the above-mentioned atmega32 PS/2-to-USB converter, and make it work correctly. If you are going this far, you can also swap in the inverted T arrow keys, the 6-key cursor control group, etc, into the F-ATs numpad and remap it in the converter, too.

Good luck finding an F-AT for less than $300 these days though, even a junky one that needs rebuilt. :( They are great keyboards though, if you can snag one and convert it to ISO layout. For me I think it's tied with the Zenith black-label XT keyboard. The only keyboard I like better than the F-AT and the black label Zenith is the earlier version of the Apple IIgs keyboard with the orange keystems (for which there is also an ADB-to-USB converter in the above github, incidentally).

If you do decide to take apart an F-AT to rearrange they keys, be aware that they can be a real PITA to get back together, and there is a foam sheet in there that will probably need to be replaced, which involves punching a ton of holes in it (I use an empty .30-06 case cut off at the point where the diameter is correct, with the edge sharpened). Do your research before tearing one apart, or you may be at your wit's end trying to get it back together. And be aware that modifying your $300 vintage keyboard like that will probably make some people go ballistic. But hey, if it's going to be the daily driver, ya gotta do what you gotta do.
 
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Does the firmware allow you to use the keyboard for power on?

I don't know. If it's some kind of "media key" with a special scancode or something, I suspect that the TMK adapter could be made to do it some way, but you'd need to keep the adapter powered while the host machine was off.


Does the USB port supply enough power to run an IBM Model F?

My F-ATs have worked through the converter without needing external power on every machine I've tried them on so far. I cannot speak for the F-XT, but other XT boards of the same vintage have been fine too.
 
If you're talking about replacing the Model F's buckling spring capacitance switches with the Model M's buckling spring membrane switches, I'd argue that the Model F mechanism is superior.

There are two different Model Fs. The earlier is the "Model F" (aka "Model F-XT"). It is an XT keyboard electrically, and will not work with an AT or PS/2 keyboard interface without a converter. You can make an XT to USB keyboard converter with a cheap atmega32u4 unit as detailed here: tmk_keyboard/converter/ibmpc_usb at master · tmk/tmk_keyboard · GitHub

The layout of the F-XT is pretty awful. I like the key action, but I hate the layout.

The Model F-AT will work out of the box with, well, an AT. It will also work on a PS/2 keyboard port with a simple DIN5 to PS/2 adapter cable. You can also convert it to USB with a different adapter that you can find in the same github as the above adapter.

The F-AT layout is better than the F-XT, but it still has a funky arrangement of Backspace, Backslash, and Enter. However, even though the F-AT doesn't have removable keycaps like the Model M, the key stems themselves are exactly the same. You can take apart an F-AT, move some of the capacitive flipper things around into a Model M layout (there are unused pads on the board and holes in the metal frame that match the Model M layout), put it back together, and substitute those three keys off a Model M, and have your proper ISO layout. IIRC backspace is the only one that needs moved, but I can't remember for sure.

However, in this configuration it will not send the correct scancodes for the keys you moved around. This can be corrected by making your own keymap for the above-mentioned atmega32 PS/2-to-USB converter, and make it work correctly. If you are going this far, you can also swap in the inverted T arrow keys, the 6-key cursor control group, etc, into the F-ATs numpad and remap it in the converter, too.

Good luck finding an F-AT for less than $300 these days though, even a junky one that needs rebuilt. :( They are great keyboards though, if you can snag one and convert it to ISO layout. For me I think it's tied with the Zenith black-label XT keyboard. The only keyboard I like better than the F-AT and the black label Zenith is the earlier version of the Apple IIgs keyboard with the orange keystems (for which there is also an ADB-to-USB converter in the above github, incidentally).

If you do decide to take apart an F-AT to rearrange they keys, be aware that they can be a real PITA to get back together, and there is a foam sheet in there that will probably need to be replaced, which involves punching a ton of holes in it (I use an empty .30-06 case cut off at the point where the diameter is correct, with the edge sharpened). Do your research before tearing one apart, or you may be at your wit's end trying to get it back together. And be aware that modifying your $300 vintage keyboard like that will probably make some people go ballistic. But hey, if it's going to be the daily driver, ya gotta do what you gotta do.

Lee, can you post a photo of a modified F-AT?
 
Sure, although I didn't realize how filthy the ol' girl is getting until I took the picture. Now I'll have to deep clean it before I use it again LOL.

Note that the F is painted, so once they get some wear they start getting that TRS-80 look to them where the paint wears off.

20220615_231411.jpg
 
You know, I ought to try to put a whole raspberry pi in that thing and use it for a portable with one of those folding monitors...... 🤔

PS: I said "ISO layout" up there somewhere when I probably should have said "ANSI layout". Oops.
 
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If you're talking about replacing the Model F's buckling spring capacitance switches with the Model M's buckling spring membrane switches, I'd argue that the Model F mechanism is superior.

There are two different Model Fs. The earlier is the "Model F" (aka "Model F-XT"). It is an XT keyboard electrically, and will not work with an AT or PS/2 keyboard interface without a converter. You can make an XT to USB keyboard converter with a cheap atmega32u4 unit as detailed here: tmk_keyboard/converter/ibmpc_usb at master · tmk/tmk_keyboard · GitHub
There are also 122-key Model Fs (and Model Ms).
The F-AT layout is better than the F-XT, but it still has a funky arrangement of Backspace, Backslash, and Enter. However, even though the F-AT doesn't have removable keycaps like the Model M, the key stems themselves are exactly the same. You can take apart an F-AT, move some of the capacitive flipper things around into a Model M layout (there are unused pads on the board and holes in the metal frame that match the Model M layout), put it back together, and substitute those three keys off a Model M, and have your proper ISO layout. IIRC backspace is the only one that needs moved, but I can't remember for sure.

However, in this configuration it will not send the correct scancodes for the keys you moved around. This can be corrected by making your own keymap for the above-mentioned atmega32 PS/2-to-USB converter, and make it work correctly. If you are going this far, you can also swap in the inverted T arrow keys, the 6-key cursor control group, etc, into the F-ATs numpad and remap it in the converter, too.
You can also burn a replacement microcontroller for the 84-key or 122-key Model F that remaps the scancodes internally.
 
The model F that I have is 84 key. It has IBM Personal Computer written on the face plate of the keyboard. The backplate doesn’t have a label but, I can open it up to find out more. Yes, I, too, paid and arm/leg for this keyboard. So, I would like to find a method where this keyboard could be used other than building another IBM PC machine.

Thank you for the links and I’ll look into them. For this 286 motherboard, I have found a USB keyboard with an adapter to PS/2 and a second adapter from PS/2 to Din 5 seems to work. If course, it sticks out about 5 inches from the back os the machine. So, that’s not a problem.
 
The model F that I have is 84 key. It has IBM Personal Computer written on the face plate of the keyboard. The backplate doesn’t have a label but, I can open it up to find out more. Yes, I, too, paid and arm/leg for this keyboard. So, I would like to find a method where this keyboard could be used other than building another IBM PC machine.

Thank you for the links and I’ll look into them. For this 286 motherboard, I have found a USB keyboard with an adapter to PS/2 and a second adapter from PS/2 to Din 5 seems to work. If course, it sticks out about 5 inches from the back os the machine. So, that’s not a problem.

Yeah, that sounds like the Model F-XT. If you had the F-AT, it would say so on the logo thinger.

That TMK atmega32 thinger will fix you right up, if you want to use it on a machine that supports USB keyboards. If you aren't comfortable making your own, he sells them preassembled too.

If you want to use it on a PS/2 or AT keyboard port, it gets a little hairier. That straight though adapter like you're using on that USB keyboard you mention above probably won't work, as IIRC the USB boards that work with those things actually support the AT protocol internally and switch over when they detect that they are plugged into the passive adapter some way. I may be full of poo about that, though.

A project on my todo list is to write some code for an ESP8266 to bit bang the AT protocol on some GPIO pins, but I don't know when I'll get around to that. I don't know of any commercial XT->AT converters other than the Hagstrom board, and it's kinda expensive for what it is.
 
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