Blank PCBs

[Gronk]

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.

[regack]

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. 

[SpAmRaY]

Like regack says we need more info but what about these?

https://techkeys.us/products/the-enabler

Sent from my SM-G930V using Tapatalk

[_rubik]

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.

[Gronk]

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

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.

[_rubik]

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

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

[Gronk]

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

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

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. 

[_rubik]

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.

[Gronk]

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!

[OldDataHands]

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...