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geekhack Projects => Making Stuff Together! => Topic started by: samwisekoi on Sun, 03 May 2015, 14:06:57
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Greetings! This is the start of a build log, or more particularly a re-build log for an IBM F-122 terminal keyboard that I am restoring, case modding, and for which I am creating and adding some custom electronics. Thanks for this build go to JWAZ (https://geekhack.org/index.php?action=profile;u=14188) for finding the F-122 on e-Bay and Soarer (https://geekhack.org/index.php?action=profile;u=4274) for his wonderful terminal keyboard-to-USB converter.
Starting Point
(http://i.imgur.com/t9JLWgQ.jpg)
IBM F-122 Terminal Keyboard, case removed.
I started with an F-122 in good shape. No missing parts, working spacebar, nothing broken. Good deal. To that mix, I added/will add:
- Teensy
- Soarer converter software
- USB cable and A and B connectors
- Custom PCB and electronics
- Full set of PC-122 keycaps plus some extras from Unicomp
- Mylar labels and misc parts, also from Unicomp
- Braided cable wrap, terminals, etc. from MDPC and Lutro0 Customs
- Other things I've forgotten now and/or have not discovered I need!
I've started an Imgur album here (http://imgur.com/a/dGKxA#8).
I've finished the tear-down and the first couple of big sub-projects already. I'll add them in subsequent posts.
- Ron | samwisekoi
Sig auto-typed by my GH36 LH keypad.
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Looking forward to seeing your progress! Lovely as always.
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I also am working on restoring an F122. Look forward to using your album to help me :)
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Good luck for your project! Is the big-ass reverse Return key common for older IBM models?
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Step 2: Super Soarer PCB
Since this F-122 will be my primary work keyboard AND serve as a user-experience trial for the future SD-122/155, I wanted to enable the keyboard with more intelligence than the average protocol converter provides. However, the Soarer converter firmware is a great base, and will be used as a starting point.
But I want more capabilities!
So I created a little custom PCB I am calling the "Super Soarer" to add some capabilities via hardware. Specifically, the PCB adds:
- Status LEDs
- NUMLOCK on/off logic for the NUMLOCK LED
- Power LED
- 90-degree pins for a reversible cable to the F-122 logic PCB
(http://i.imgur.com/1oW7ux5.jpg)
Samwisekoi "Super Soarer PCB with temporary LEDs installed
The Teensy is as you would expect, but working clockwise around the PCB there is a transistor that switches state when the NUMLOCK circuit is enabled, resistors for the NUMLOCK on/off logic circuit, resistors for the LEDs, a dim red power indicator LED, two 2-pin and one 3-pin LED connectors, and a polarized 4-pin connector that matches the terminal-out pins on the F-122 logic PCB.
Most of that is simple and obvious, but the NUMLOCK on/off logic circuit is worth some explanation.
NUMLOCK on/off logic circuit
Because this keyboard -- or really any keyboard with 104 or more keys -- does not need the directional keys on the number pad, in my opinion, the NUMLOCK key actually puts the keyboard into an error state. That is, when you press the NUMLOCK key, the number pad loses all of its numbers! Unfortunately, again, IMO, the NUMLOCK LED works backwards. I want the NUMLOCK LED to be off under normal use -- just like the CAPSLOCK LED -- but if the NUMLOCK circuit is engaged, the associated LED should light to indicate an error condition.
The NUMLOCK on/off logic circuit enables just this behavior by lighting the LED when the NUMLOCK is OFF instead of when it is ON like it should be. However, I am aware that there may be situations where this isn't the right answer, perhaps when converting a smaller form factor terminal keyboard WITHOUT a number pad. Accordingly, the NUMLOCK LED has three pins. Ground (to the resistor), ANTI-NUMLOCK, and regular old NUMLOCK. I made this a three-pin connector in case someone (not me) wanted to use a two-color LED to indicate BOTH possible states with different colors.
To test this build, I soldered the LEDs directly to the pins. Once I have modded the cover for the LEDs, I will remove those and make a six-pin connector and a cable that runs to the LEDs attached to the cover.
Just to be complete, here is the underside of the hard-wired PCB. Not beautiful, but fully functional and well-tested:
(http://i.imgur.com/xdZffJf.jpg)
Underside of the Samwisekoi "Super Soarer" PCB
If anyone is interested I can publish a parts list and schematic. If many people are interested, this would be simple to turn into a proper PCB.
More to come soon,
- Ron | samwisekoi
Sig auto-typed by my GH36 LH keypad.
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Good luck for your project! Is the big-ass reverse Return key common for older IBM models?
As far as I have seen, all the 122-key IBM terminals have ISO style Enter and Left Shift, hence my guide:
https://geekhack.org/index.php?topic=48786.0
For any newbies who do not enjoy re-inventing the wheel - always start here (thanks, JDC):
https://geekhack.org/index.php?topic=69582.0
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Good luck for your project! Is the big-ass reverse Return key common for older IBM models?
As far as I have seen, all the 122-key IBM terminals have ISO style Enter and Left Shift, hence my guide:
https://geekhack.org/index.php?topic=48786.0
Thanks, fohat.digs!
I got the parts from Unicomp to switch that key to ANSI, but so far do not plan to do so.
- Ron | samwisekoi
Sig auto-typed by my GH36 LH keypad.
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very interesting... i'm also doing a f-122 mod (using tmk, since it's open source, and not soarers), to add num/caps/scroll lock leds. other than these leds i've added an OLED 1.5" display which will show more info and debug/config stuff. still doing this part, though.
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Cool project. I look forward to seeing the result. :thumb:
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Following.
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Step 3: Custom Cables
For this build, there are two custom cables I need to make:
1. 4-wire cable from the F-122 logic PCB to the Super Soarer PCB. I wanted this to be clean, polarized to match the OEM cable, and symmetrical, so it could be plugged in either way 'round.
2. USB cable from the Teensy's Mini-B connector out to the world and into a USB 2.0 A connector. For this cable, I very, very much wanted an OEM-looking beige ("pebble") coiled cable that looked like it came that way from the factory.
From the F-122 Logic PCB to the Super Soarer PCB
This was the easy cable. I went to Pololu.com (https://www.pololu.com/category/39/cables-and-wire), a robot-hobbiest supply shop, and bought an assortment of pre-crimped wires and a pair of 2x3 housings. I then connected them to mate with the Logic PCB, wrapped them in MDPC cable wrap, and added some shrink-wrap. Since the Super Soarer PCB input pins match the F-122 Logic PCB pins, the cable can go either direction.
(http://i.imgur.com/1Yvxy3a.jpg)
F-122 Logic PCB keyboard cable pins to be connected to the Super Soarer
(http://i.imgur.com/2yf6d2r.jpg)
Symmetrical cable to connect the F-122 Logic PCB to the Super Soarer PCB
Custom Retro-USB Coiled Cable
This was harder and took more thought. Also a bunch of parts to test for utility, function, and look.
The easy part: buying parts.
First off, I purchased a replacement coil cable for the F-122 terminal keyboard from Unicomp. That had the wrong connector on each end, but the correct look, coil, and strain relief fitting. Then on to e-Bay, where I bought a bunch of different USB connectors. Both plastic and metal USB-A male connectors, plastic and metal USB-B connectors, and finally plastic USB Mini-B connectors.
(http://i.imgur.com/kHfFvjb.jpg)
Raw material from Unicomp, e-Bay, and Adafruit
The point of no return: replacing the exterior end connector.
The Unicomp cable came with a beautiful molded plastic and metal circular connector -- with an engraved IBM logo! For all I know it is Mil-Spec. Anyhow, beautiful. I considered replacing it with a metal USB-A connector, but in the end decided that wouldn't look as nice as a clean, hooded plastic connector. I think that end came out very nice.
(http://i.imgur.com/BuzsA77.jpg)
Soldering the USB-A connector.
(http://i.imgur.com/576AsBP.jpg)
Housing installed and shrink-wrap in place.
To be continued...
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First off, I purchased a replacement coil cable for the F-122 terminal keyboard from Unicomp.
I am flabbergasted that Unicomp sells replacement F-122 cables, new!
You may be lucky enough, one day, as I was, to find the female cable end that screws in. Works great for an outboard Teensy.
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First off, I purchased a replacement coil cable for the F-122 terminal keyboard from Unicomp.
I am flabbergasted that Unicomp sells replacement F-122 cables, new!
You may be lucky enough, one day, as I was, to find the female cable end that screws in. Works great for an outboard Teensy.
I had several conversations with them along the way, but yes they do, and it is very cool.
I also thought about the external Teensy box, but in the end I wanted to be able to plug this into anything. Also, I needed the converter to be internal to make the blinky lights work.
But you bet I put that cable end in a safe place!
Best regards,
- Ron | samwisekoi
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Are the numpad direction keys disabled as a result of the mod? I didn't quite get many things...
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Are the numpad direction keys disabled as a result of the mod? I didn't quite get many things...
No, in fact I put NUMLOCK as ALT-TAB in the same location as NUMLOCK would normally be found.
(http://i.imgur.com/kWXjjvk.png)
F-122 keyboard layout by samwisekoi 2015
So if you press that key-combination, then (a) the NUMLOCK light goes ON, and (b) the numpad directional keys are engaged.
- Ron | samwisekoi
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Hoping to see this finished one day soon Sam. Good luck!