Author Topic: Model F Mod Log (Read 40798 times)

msiegel · « **on:** Sun, 04 October 2009, 00:51:05 »

Hi :) This is an ongoing log of my extensive Model F modification.

Status: Researching capacitive sensors

I'm planning the following:

[*]*no* case
[*]modified top plate & backplate. to be painted.
[*]original barrels, hammers, springs
[*]new acoustic/mounting foam
[*]original keys, new layout. replacement model m keys for backslash, enter, alt, space
[*]new matrix pcb (2-sided)
[*]modified insulator sheet
[*]new controller: Teensy dev board with GEEKey open source USB firmware; custom capacitance measurement circult; flywired & soldered to matrix
[*]new feet (cork, rubber, or silicone)
[*]original interlocking tabs; a few added nuts & bolts
[/LIST]

This will take awhile to implement :D

Bill of Materials - all prices shipped
IBM Model F AT Keyboard $60
Teensy microcontroller; RGB LED $30 from Adafruit
Replacement Model M keys and caps $20 from Clickykeyboards
PCB Etchant $11 picked up at The Shack (actually in stock!)
12x12" sheet of 2-sided "scissor-cut" copper clad ...

Tools
Screwdriver
Tape Measure
Nibbler
C Clamps
Saw
Hammer & Bag of Concrete (see recent posts)

msiegel · « **Reply #1 on:** Sun, 04 October 2009, 00:59:11 »

here's the initial layout i'm aiming for... pick one

it's a little like the hhkb, as i prefer smaller boards. hopefully the lack of dedicated arrow keys will be easy to adjust to.

edit: added arrow keys, because i use them a lot. see more recent posts.

- the top one re-uses the model f's backspace but has a model m backslash
- the bottom one uses a model m tab key to achieve an hhkb-like backspace
- model m enter key and bottom row keys are used in both
- i have no caps lock key, but i do use an option key on the mac

thanks to quadibloc for the lovely layout illustrations i've stolen from

msiegel · « **Reply #2 on:** Sun, 04 October 2009, 01:10:02 »

would a model f pcb fit in this case:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140333923993&ssPageName=ADME:B:WNASIF:US:1123

ch_123 · « **Reply #3 on:** Sun, 04 October 2009, 04:51:13 »

I dont think that terminal board is a Model F.

JBert · « **Reply #4 on:** Sun, 04 October 2009, 07:14:57 »

"Space bar transplant" - what do you mean here? Replacing it with a lighter model M one?

I think it is possible to reuse the old one though, all I did was to bend the stabilizer spring so it had less up-force.

msiegel · « **Reply #5 on:** Sun, 04 October 2009, 10:32:55 »

Quote from: JBert;122800

"Space bar transplant" - what do you mean here? Replacing it with a lighter model M one?

replacing it with a *smaller* model m one

the model f pcb has capacitive pads for 4 meta keys on the bottom row... but the lonnnnng model f space bar is in the way of 2 of them. by substituting a model m space bar, a model f's bottom row can have the same layout as a model m

msiegel · « **Reply #6 on:** Sun, 04 October 2009, 10:35:23 »

Quote from: ch_123;122798

I dont think that terminal board is a Model F.

it's not... but, if the curvature is right, and if the key-block openings are in the right places to match model f's switch pads, then it might make a good replacement for the giant old model f case

msiegel · « **Reply #7 on:** Sun, 04 October 2009, 10:37:15 »

Quote from: ripster;122826

I like the second layout better. That's easy to do on a Model M (although I do like the function keys even better next to the space bar and having two of them). Whats a OPT key?

your retr0right simulation is awesome XD

Option key is used on the Mac; like having that "Windows" key for Windows

timw4mail · « **Reply #8 on:** Sun, 04 October 2009, 11:59:20 »

Yeah, the white balance was off.

rdh · « **Reply #9 on:** Sun, 04 October 2009, 12:55:29 »

Since the Windows / ⌘ / ◇ keys are all really the same thing (they send the same scan codes), I like to refer to 'em generically as the 'logo' key.

Anybody got a good generic name for the Alt/Opt key? (Do we need one?)

Quote from: ripster;122826

And don't forget the Retr0brite part of the mod.
Show Image

That pumpkin-orange color is appropriately Octoberish, I think.

msiegel · « **Reply #10 on:** Sun, 04 October 2009, 13:05:19 »

Quote from: ripster;122881

This is a great article on the Apple key history.

cool

hey, do we have a history section somewhere?

ch_123 · « **Reply #11 on:** Sun, 04 October 2009, 13:29:13 »

Quote from: ripster;122885

No - the IBM entry in the wiki is kinda stalled

Im working on it. At least some of it should be up by this time next week.

rdh · « **Reply #12 on:** Sun, 04 October 2009, 14:26:37 »

Heh. I just realized whose web site had the scan I trimmed to get this:

:-)

msiegel · « **Reply #13 on:** Sun, 04 October 2009, 15:19:18 »

Quote from: ripster;122885

Funny thing is although I started out on Apple IIs I can't remember anything about the keyboard.

iirc, it was like brown cherries but without a tactile bump

Xuan · « **Reply #14 on:** Sun, 04 October 2009, 20:35:33 »

Quote from: rdh;122878

Anybody got a good generic name for the Alt/Opt key? (Do we need one?)

Another name for it is Meta from List machines, emacs still refers to it like that.

lowpoly · « **Reply #15 on:** Mon, 05 October 2009, 10:21:53 »

Here are the 73X3832 pics:

http://geekhack.org/showthread.php?t=7377

quadibloc · « **Reply #16 on:** Tue, 06 October 2009, 21:13:25 »

An important question for the Model F experts in this thread. When the key is depressed on a model F keyboard, does the plate go towards the printed circuit board... or away from it?

And you know why I'm asking - could 3278 keys be used on a Model F board, or not?

msiegel · « **Reply #17 on:** Tue, 06 October 2009, 21:21:05 »

Quote from: quadibloc;123606

An important question for the Model F experts in this thread. When the key is depressed on a model F keyboard, does the plate go towards the printed circuit board... or away from it?

And you know why I'm asking - could 3278 keys be used on a Model F board, or not?

definitely toward. i just verified this with a disembodied keyswitch module

JBert · « **Reply #18 on:** Wed, 07 October 2009, 07:52:00 »

Quote from: quadibloc;123606

An important question for the Model F experts in this thread. When the key is depressed on a model F keyboard, does the plate go towards the printed circuit board... or away from it?

And you know why I'm asking - could 3278 keys be used on a Model F board, or not?

The hammers are pressed down when you press the key, just like a model M.

Whether it can detect keypresses from a 3278 depends on the controller. If it only detects changes in capacitance instead of a drop in capacitance, it might work.

timw4mail · « **Reply #19 on:** Wed, 07 October 2009, 10:40:45 »

You're expecting this to take a while, aren't you Ripster?

msiegel · « **Reply #20 on:** Wed, 07 October 2009, 10:48:24 »

can anyone recommend a laser cutting service, for stainless steel and plastic?

i'm looking at alternatives for fabrication of a new backplate and top plate / keymodule template.

timw4mail · « **Reply #21 on:** Wed, 07 October 2009, 10:52:05 »

Wouldn't aluminum be cheaper?

msiegel · « **Reply #22 on:** Wed, 07 October 2009, 10:58:00 »

Quote from: timw4mail;123709

Wouldn't aluminum be cheaper?

i don't know - do you think it would?

i was also considering plastic for the new top plate / template. if the plates were flat instead of curved (heresy, i know), then the foam pad might not be needed.

timw4mail · « **Reply #23 on:** Wed, 07 October 2009, 10:59:30 »

I'm pretty sure, as aluminum is a pretty common element, and stainless steel is an alloy of several different metals, and there are several different grades of stainless steel available...it just simplifies things to get aluminum.

itlnstln · « **Reply #24 on:** Wed, 07 October 2009, 12:11:03 »

Quote from: timw4mail;123714

I'm pretty sure, as aluminum is a pretty common element, and stainless steel is an alloy of several different metals, and there are several different grades of stainless steel available...it just simplifies things to get aluminum.

Aluminum is very difficult to manufacture as it has to be "freed" from other minerals, rocks, etc., usually bauxite. Check it.

JBert · « **Reply #25 on:** Wed, 07 October 2009, 12:54:52 »

Quote from: msiegel;123712

i don't know - do you think it would?

i was also considering plastic for the new top plate / template. if the plates were flat instead of curved (heresy, i know), then the foam pad might not be needed.

I think the foam is only there to stick to the spring tubes so they won't fall out when you separate the backplate from the front.

After all, now that the foam disintegrates even when slightly touched, it can't do anything structural or you would have felt the difference.

msiegel · « **Reply #26 on:** Wed, 07 October 2009, 12:59:55 »

hmm... it turns out the bottoms of the keyswitch modules are not perfectly flat.

they're very slightly curved.

i'm guessing this is by design, to match the curvature of the plates.

msiegel · « **Reply #27 on:** Wed, 07 October 2009, 13:04:47 »

Quote from: ripster;123733

Lasers for plastic?

for accuracy

plus, isn't abs kind of hard to drill

lowpoly · « **Reply #28 on:** Wed, 07 October 2009, 13:51:44 »

Check emachineshop.com for something like this. They have a vast selection of materials. If this is going to hold the bent pcb then regular Aluminum will be too soft. Stainless will be nice but expensive. Most keyboards seem to have regular steel plates with some sort of surface treatment.

The emachineshop software is good for mostly two-dimensional objects. You should be able to bend it at a local tool shop later if the software doesn't allow for this.

Shapeways is another rapid prototyping service.

msiegel · « **Reply #29 on:** Wed, 07 October 2009, 13:56:10 »

Quote from: lowpoly;123747

Check emachineshop.com for something like this.

fascinating... thanks lowpoly

quadibloc · « **Reply #30 on:** Wed, 07 October 2009, 15:14:00 »

Quote from: ripster;123674

Tell me when you have a Model F with a usable layout.

I'd have one already if I thought the ISO keyboard was usable - as I have two IBM 122-key keyboards, one a Model M terminal keyboard, and one the big Model F one for the 3270 PC.

I think the only way to mod a Model F to change the key locations would be to make your own printed circuit board to replace the one that came with the keyboard. Electronics hobbyists have done it, so it's possible.

msiegel · « **Reply #31 on:** Wed, 07 October 2009, 15:52:50 »

Quote from: quadibloc;123760

I think the only way to mod a Model F to change the key locations would be to make your own printed circuit board to replace the one that came with the keyboard. Electronics hobbyists have done it, so it's possible.

i'm interested in seeing their work. do you remember where you saw that?

Quote from: quadibloc;123760

I'd have one already if I thought the ISO keyboard was usable - as I have two IBM 122-key keyboards, one a Model M terminal keyboard, and one the big Model F one for the 3270 PC.

edit: how come the 3270 board isn't usable... interface compatibility?

msiegel · « **Reply #32 on:** Fri, 09 October 2009, 10:25:45 »

note: the plastic inserts in the barrels of a model f are a different shape than the model m's.

this means that using a model m's stabilized keys, such as the enter key, requires the model m's barrel inserts as well as its keys.

...now working on getting a model m, for ansi keycaps and barrel-inserts, and to test whether the membranes can be used as capacitive sensors...

quadibloc · « **Reply #33 on:** Fri, 09 October 2009, 15:00:51 »

Quote from: msiegel;123765

i'm interested in seeing their work. do you remember where you saw that?

It used to be fairly common for electronics hobbyists to make their own printed circuit boards. Just single-sided single-layer, though. You could buy a kit where you got a board completely covered with copper on one side, and you stuck a mask to the copper, and then used an acid solution provided in the kit to remove the copper that was exposed.

Quote from: msiegel;123765

edit: how come the 3270 board isn't usable... interface compatibility?

My reference to usability was in terms of the layout. The main typing area of the 122-key keyboard is laid out the same way as an international 102-key keyboard, meaning that there is an extra key between Z and the left-hand shift key.

The controller apparently only has the issue of not sending key release codes, and there is supposedly a workaround for it according to posts on the subject here, but I'm afraid I haven't quite understood them well enough to understand what the workaround is: sending commands to the keyboard's controller, patching my computer's BIOS, using special driver software, or what.

msiegel · « **Reply #34 on:** Fri, 09 October 2009, 15:03:47 »

Quote from: quadibloc;124174

It used to be fairly common for electronics hobbyists to make their own printed circuit boards. Just single-sided single-layer, though. You could buy a kit where you got a board completely covered with copper on one side, and you stuck a mask to the copper, and then used an acid solution provided in the kit to remove the copper that was exposed.

this pcb material looks like it might be thin enough to be flexible:
http://www.goldmine-elec-products.com/prodinfo.asp?number=G17115

msiegel · « **Reply #35 on:** Thu, 15 October 2009, 00:49:53 »

ordered a "teensy" avr dev board from adafruit.

i just couldn't stand it any longer

this will be most of the hardware for the new controller.

msiegel · « **Reply #36 on:** Thu, 15 October 2009, 19:36:54 »

note to self: don't require many fasteners for assembly!

remember what a pain it was working with 42 screws/nuts for the model m mini mod

msiegel · « **Reply #37 on:** Thu, 15 October 2009, 20:49:29 »

you guys can chime in anytime... but this here is a log, man.

i have an older cellphone camera

msiegel · « **Reply #38 on:** Sat, 17 October 2009, 01:51:18 »

design idea for capacitance measurement:

AVR PWM --> (555 + Sensor Pads) --> Smoothing Capacitor --> AVR ADC

in this scheme the adc will have to measure ~100K samples per second
edit: hmm, 15K per second may be the limit

reference:
http://www.sokcapacitor.com/learning/2008/Capacitance-meter-with-two-555-timers-59.html

msiegel · « **Reply #39 on:** Sat, 17 October 2009, 02:40:51 »

the top and bottom plates are flat stainless steel, pcb is flat, and the keyboard has a rubber gasket running around the outside edge.

a small controller card is sandwiched between the steel plates, and a single multicolor led indicates caps lock, Fn key activation, and special modes.

main-cluster keys are as close as possible to their relative positions on an ansi layout board: esc is still at the upper left of the board, and backspace at the upper right. only tilde is moved.

msiegel · « **Reply #40 on:** Sat, 17 October 2009, 15:57:58 »

pic of the day: the lab, where ibm technology is analyzed

msiegel · « **Reply #41 on:** Sat, 17 October 2009, 18:23:25 »

Capacitive Sensor Design Resources

http://www.planetanalog.com/showArticle.jhtml?articleID=196902891

http://www.slideshare.net/ruthmoore08/capacitance-sensing-pccompatible-usb-capsense-matrix-keyboard

http://sensi.org/~svo/capsensor/index.en.html

http://www.cypress.com/?docID=2192 (PDF)

http://www.planetanalog.com/showArticle.jhtml?articleID=189602704

https://secure.cypress.com/?docID=2442 (PDF)

msiegel · « **Reply #42 on:** Sat, 17 October 2009, 22:12:14 »

Quote from: ripster;126478

Hey that pic looks fine! You might want to think of making sure the controller picks up the "extra" pads - the two next to the shift keys and the one next to ENTER (can't tell from the pic if that one is there). That way when you play with layouts later all you have to do is stuff the key wells differently with springs/hammers/keys.

thanks

yes, i guess i should figure out how to use the existing pcb first, with a new controller... and wait until later to make a new pcb.

msiegel · « **Reply #43 on:** Sat, 17 October 2009, 22:20:02 »

it was working initially, with an old HP 286, but that computer is gone now

although i have a ps/2 to usb adapter which worked well with my model m, maybe there's not enough power available?

msiegel · « **Reply #44 on:** Sat, 17 October 2009, 22:53:29 »

there's a teensy development board coming in about a week

i still have to come up with a capacitance measurement circuit, figure out the ibm matrix, then switch mnemonix's usb code to use the avr's hardware usb, but still... it's coming.

edit: i just plugged the controller and matrix pcb into a usb converter... no output :-/
i'll try tim4

lowpoly · « **Reply #45 on:** Sun, 18 October 2009, 05:24:25 »

Why not bend the top and bottom plates?

How are they held together on the Model F, could you explain this?

ch_123 · « **Reply #46 on:** Sun, 18 October 2009, 05:26:29 »

Someone needs to get this guy a Beam Spring keyboard. Nao.

ak_nala · « **Reply #47 on:** Sun, 18 October 2009, 06:50:12 »

Quote from: msiegel;126474

Capacitive Sensor Design Resources

http://www.planetanalog.com/showArticle.jhtml?articleID=196902891

http://www.slideshare.net/ruthmoore08/capacitance-sensing-pccompatible-usb-capsense-matrix-keyboard

http://sensi.org/~svo/capsensor/index.en.html

Another article mentioned in the Site Editor's Note in the first link - -

http://www.planetanalog.com/showArticle.jhtml?articleID=189602704

EDIT: Also found a direct link to a PDF of the article in your second link that is a bit more convenient to view than the flash-based version on the slideshare site - -

https://secure.cypress.com/?docID=2442

msiegel · « **Reply #48 on:** Sun, 18 October 2009, 11:27:18 »

the plates are connected by sliding tabs. one of the tabs is longer, and bends to lock the plates together.

i'd love the plates to be curved, but i have no idea how to get the exact curvature

msiegel · « **Reply #49 on:** Sun, 18 October 2009, 11:28:42 »

Quote from: ak_nala;126555

Another article mentioned in the Site Editor's Note in the first link - -

http://www.planetanalog.com/showArticle.jhtml?articleID=189602704

EDIT: Also found a direct link to a PDF of the article in your second link that is a bit more convenient to view than the flash-based version on the slideshare site - -

https://secure.cypress.com/?docID=2442

thank you

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Author Topic: Model F Mod Log (Read 40798 times)