To touchpad or not to touchpad?

[punforgettable]

So I recently got my first mechanical keyboard -- a 1989 Omnikey 102 Gold Label. Haven't plugged the sucker in yet (still finishing my desktop build at home), but I'm already thinking of a mod:

Replace the tenkey caps/switches with a touchpad. Something like what was done here: http://forums.bit-tech.net/showthread.php?s=7fd815b3e346c89c615326a022d8d81a&t=121291&pp=29&page=2

Is it possible? Is it heresy? What do you all think? I don't use a tenkey, and I love touchpads, so to me it seems nice. One caveat is that the board will mainly be attached to a linux box, so I would want to use a linux-friendly touchpad -- maybe something by snaptics, maybe the pad from the Acer C720 chromebook...

Suggestions?

[dorkvader]

Is it possible?

yeah it's possible. This is geekhack

One easy way I see of doing it is to get a thin touchpad like the one logitech makes (make sure the horizontal and vertical dimensions are about the same as your tenkey) and install it. Since it'll probably be USB you can get a USB hub and a PS/2 to USB converter, mount the hub internally and run one USB cable out the back.

Unfortunately the trackpad might be too thick requiring your to desolder the switches and cut off the end of the plate. If you have to cut the PCB as well you will likely have to "repair" or reroute traces. If it comes to that there are a few premade guides from people that cut off the tenkey on fullsize keyboards I can point you to.


But yeah: it's totally possible.

If you want just a trackpad from like a laptop I might have a spare (synaptics). Usually they operate on PS/2 and you will need to find the pinout from the trackpad datasheet. Step one is finding the proper size trackpad. I have stacks of them from cherry G80-8113, or you can get replacement parts for laptops.

One benefit of this is you can just desolder the switches and mount it over the plate, only doing reversible mods to your keyboard. Unfortunately, it'll be a lot harder to mount the buttons. I recommend double stick foam tape to mount the trackpad. Also the hard part will be connecting the PS/2 cable to the trackpad. Almost all of them use a zif cable.

Let me know what you're thinking and I can point you to some options.

[punforgettable]

Thanks for the tips! I definitely want to stick with reversible mods if I end up doing this, so messing with the circuit board is not an option. Also I actually own the logitech touchpad and confirm that it is a beast in terms of dimensions.

The tenkey area on this Omnikey is approximately 3.5" long by 2.75" wide, so if you have suggestions or pads about that size do let me know! Buttons are more of a nice-to-have than critical for me -- I'm more of a tapper than a clicker. Other than that as I mentioned there are a couple outlier requirements that may make a project like this more difficult than normal:

1)pad has to work with linux
2)would be nice if it supports gestures > 2 touch points

Per Syanptics' website it seems they started supporting full multitouch gestures around 2010: http://www.synaptics.com/en/gesture-suite-linux.php however I think this is more of an OEM driver than anything, which is why I was thinking a chromebook touchpad may be promising. The c720 in particular is documented to work well with archLinux, but I'm not married to that model of course. Don't even know what size it is.

archLin link: https://wiki.archlinux.org/index.php/Acer_C720_Chromebook#Touchpad_Configuration