geekhack
geekhack Projects => Making Stuff Together! => Topic started by: Gronk on Mon, 20 November 2017, 16:09:32
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Does anyone sell blank keyboard PCBs that use Cherry MX switches? I've wanted to buy a replacement keyboard for a TRS-80 Model 4 since they are getitng hard to find and most of them had keyboards that used melted plastic pins to hold them together and over time those break apart.
If I had a blank PCB I could manually wire the appropriate matrix. It wouldn't fit in the same space as the old keyboard unless I went TKL which wouldn't be a bad tradeoff since I rarely used the numpad anyway.
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So... like a PCB with pads in place, but no traces connecting them? And then you'd hand-wire everything? I've never seen anything remotely like that, and it certainly wouldn't save you any money in the PCB.
I'd suggest probably a plate is a better beginning point for this, but I have no familiarity with what you're working with, so I'm not sure if that would work for you. Maybe someone else will chime in with something more useful. :thumb:
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Like regack says we need more info but what about these?
https://techkeys.us/products/the-enabler
Sent from my SM-G930V using Tapatalk
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I think you're referring to the plate. You can buy those to fit almost any layout, and they're generally quite cheap. If you're talking about just building a board from scratch (and you mean buying a PCB itself), the GH60 is a great starting point and is only around $35.... but yeah, "blank pcb" doesn't really mean anything around here.
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I was looking for a PCB with the pads in place and no traces connecting them as regack asked. What the Model 4 has is an 8x8 matrix as seen on page 42 here:
http://www.classiccmp.org/dunfield/trs80/m4tech.pdf (http://www.classiccmp.org/dunfield/trs80/m4tech.pdf)
The keyboard connects to the motherboard via a ribbon cable. So I was hoping there was a PCB with the pads for soldering the switches and wires to run point-to-point that someone designed for prototyping or customization.
The product SpAmRaY posted looks like it might be a reasonable compromise. The GH60 looks like it's got traces in place so that won't work.
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I was looking for a PCB with the pads in place and no traces connecting them as regack asked. What the Model 4 has is an 8x8 matrix as seen on page 42 here:
http://www.classiccmp.org/dunfield/trs80/m4tech.pdf (http://www.classiccmp.org/dunfield/trs80/m4tech.pdf)
The keyboard connects to the motherboard via a ribbon cable. So I was hoping there was a PCB with the pads for soldering the switches and wires to run point-to-point that someone designed for prototyping or customization.
The product SpAmRaY posted looks like it might be a reasonable compromise. The GH60 looks like it's got traces in place so that won't work.
In all my years, I have never seen a pcb with pads and no traces. The entire point of pads is to interface between components and traces. The closest thing I can think of to what you're asking for is a handwire. Get a plate that you like (or get one cut), and wire the rows and columns directly to the switches. Granted, I could be missing something; I'm just relaying what I know. Take a look at this thread: https://geekhack.org/index.php?topic=87689.0 (https://geekhack.org/index.php?topic=87689.0)
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I was looking for a PCB with the pads in place and no traces connecting them as regack asked. What the Model 4 has is an 8x8 matrix as seen on page 42 here:
http://www.classiccmp.org/dunfield/trs80/m4tech.pdf (http://www.classiccmp.org/dunfield/trs80/m4tech.pdf)
The keyboard connects to the motherboard via a ribbon cable. So I was hoping there was a PCB with the pads for soldering the switches and wires to run point-to-point that someone designed for prototyping or customization.
The product SpAmRaY posted looks like it might be a reasonable compromise. The GH60 looks like it's got traces in place so that won't work.
In all my years, I have never seen a pcb with pads and no traces. The entire point of pads is to interface between components and traces. The closest thing I can think of to what you're asking for is a handwire. Get a plate that you like (or get one cut), and wire the rows and columns directly to the switches. Granted, I could be missing something; I'm just relaying what I know. Take a look at this thread: https://geekhack.org/index.php?topic=87689.0 (https://geekhack.org/index.php?topic=87689.0)
I've not built a keyboard since 1982 so I didn't know what's been done lately. I was just hoping there was some kind of prototype PCB, but I guess not. Are there any design files for a keyboard that I could load up in a CAD program and change the traces to match what I need?
If not then the plate and point-to-point wiring would be the way to go. If there are places that make custom plates I could even duplicate the original Model 4 layout but I think I'd like to improve on it a bit.
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I'm not the person to ask about cad/pcb design, but you can easily use a keyboard layout editor, swillkb, and lasergist to design and cut a plate according to the layout you're after:
http://www.keyboard-layout-editor.com/
http://builder.swillkb.com/
http://lasergist.com/
Granted, depending on where you live, another place to get things cut may be cheaper.
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I'm not the person to ask about cad/pcb design, but you can easily use a keyboard layout editor, swillkb, and lasergist to design and cut a plate according to the layout you're after:
http://www.keyboard-layout-editor.com/
http://builder.swillkb.com/
http://lasergist.com/
Granted, depending on where you live, another place to get things cut may be cheaper.
Thanks!
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You might consider picking up one of the many available pcbs ( with the wiring already done) and adjust which key press to send from which switch in software...