IBM KPD8923 dissasembly and trackpoint harvesting

tipo33 · 10 Jun 2012, 21:30

I was disassembling a KPD8923 to get the trackpoint and ran into some issues, so here is a guide for future reference.

Remove all the screws from the backside.

Pull up these keys and remove the screws underneath them.

Pull keyboard apart.

Remove screws and tape securing trackpoint components.

voila! Trackpoint that can be moded into your keyboard of choice.

rodtang · 10 Jun 2012, 21:39

This isn't the latest version of the trackpoint though.

Great pics non the less.

off · 10 Jun 2012, 22:02

That doesn't look like a challenge? May I ask what issues you ran across (useful for future reference for those that might run into those

)?
Also, will you be reusing the mousebuttons including the plastic tapping thingies? Since they do look easily transplantable from here..

tipo33 · 10 Jun 2012, 22:07

I removed the screws on the underside, and spent about 30min trying to pry it apart before I thought to look under the keycaps. lol. I am disassembling this and shipping it out as part of a proxy so the person didn't have to pay shipping costs for the keyboards.

rodtang · 10 Jun 2012, 22:11

tipo33 wrote:I removed the screws on the underside, and spent about 30min trying to pry it apart before I thought to look under the keycaps. lol. I am disassembling this and shipping it out as part of a proxy so the person didn't have to pay shipping costs for the keyboards.

I did the same with the version without the trackpoint.

CeeSA · 11 Jun 2012, 08:54

thanks for sharing!

Input Nirvana · 15 Jun 2012, 08:43

Question:
The IBM KPD8923 is well known for it's easily removable Trackpoint and related PCB. What Trackpoint model is it, and what has a more recent Trackpoint model that can be removed and used in the same fashion?

CeeSA · 03 Sep 2012, 21:12

I don't know. I still didn't get the pinout to make this thing work...
Anybody know the pinout for the Trackpoint of this keyboard?

Icarium · 03 Sep 2012, 22:50

Take some more pictures! Maybe we can figure it out together.

Input Nirvana · 04 Sep 2012, 05:52

The pinout was done by Bluecar5556 on GH. I sent him an ibm track point and he replaced the ribbon with a longer wire loom. It might be in here:

http://geekhack.org/index.php?topic=16112.0

If not, maybe it's in my PMs or my personal email. There is a pic somewhere with the info. Or you can pm him on GH.

I'll see if I can find the info.

Icarium · 04 Sep 2012, 08:25

I'm confused about what we're actually trying to accomplish. Are you sure that this is not one of the regular ps/2 trackpoints?

CeeSA · 04 Sep 2012, 09:57

: Trackpoint Pinout.jpg (150.87 KiB) Viewed 10197 times

this are my 2 Trackpoints view from up and down.

if i connect the trackpoint to the PS/2 connection, the TP does not work.
I don't know what todo?

*edit*

Icarium · 04 Sep 2012, 10:43

Is that the controller for the entire keyboard or just for the trackpoint part? What is the white connector in the top picture on the right for?

CeeSA · 04 Sep 2012, 10:54

this is only the controller of the TP i think. Look at 3rd pic in the op, the white 4pin connector is the connection from the TP controller to the keyboard controller.

Icarium · 04 Sep 2012, 10:57

Did the TP and the keyboard controller have separate ps/2 ports?

CeeSA · 04 Sep 2012, 11:22

i think so. Looking at the 3rd pic from tipo33 the cable to the PC split up in 2 directions. To the TP and to the keyboard.
Maybe it has 2 ps/2 connectors at the other end. But then i don't know for what is the ps/2 connector direct at the TP.
argh....

Icarium · 04 Sep 2012, 11:24

Yeah, this is a bit confusing and without at least looking at what those ICs do we won't get far I'm afraid. Do you have this keyboard? Does it work, etc.?

CeeSA · 04 Sep 2012, 11:50

ok, got it:

: TP pinout.jpg (104.44 KiB) Viewed 10174 times

I am still wondering for what is the PS/2 connector at the TP unit for?

Icarium · 04 Sep 2012, 12:11

Maybe you can connect an external mouse and it will be patched through.

Glad it works now, even though that controller is huuuge.

lowpoly · 05 Sep 2012, 11:59

This is how I connected it in the Miniguru:

Removed the plug, new capacitors to bend the legs, then fed into a ps/2 to usb converter. I also removed that additional pcb (shielding?). Not sure if that was a good idea.

Edit: Fixed broken pic

Input Nirvana · 09 Sep 2012, 06:16

Yes, you can connect a mouse to the extra ps/2 port. Is that what you're asking?

This is what I used with the Split Kinesis project.

Turns out the Kinesis Advantage is a PS/2 controller through and through, with a separate, active USB converter pcb in the case. I always thought is was for the extra USB ports and maybe a 'staging' pcb.

Input Nirvana · 23 Oct 2012, 02:43

I don't think the question ever was answered.

The keyboard has 2 completely separate and independent controller pcbs. One is for the keyboard ONLY. The other is for the trackpoint ONLY. The power cord is actually 2 power cords in 1. At one end there are 2 ps/2 connections. At the other end there are 2 4 pin block connections, one for the keyboards pcb and one for the trackpoint pcb. The track point and the keyboard are not interconnected in any way. You can remove the trackpoint and still use the keyboard and use the trackpoint in your mod.

As for the ps/2 connector on the track point pcb...you can plug another ps/2 item into it and it will work. It's a 'flow-thrugh' connection.

CeeSA · 26 Nov 2012, 09:10

Yesterday i tested the PS/2 extra connector. It supports mousemovement and a 3rd mousebutton but unfortunately no mousewheel. But this is what I want....

Any ideas? Other solutions?
1 TP
1 Mousewheel
But only one PS/2 port :/

(USB is no alternative for me, because at work i must use a PS/2 KVM)

Icarium · 26 Nov 2012, 13:59

Well, Teensy is a possible answer. Not that much work actually and suka probably has code for it ready.

7bit · 26 Nov 2012, 14:09

Please let me know what diameter the hole for the pointing stick must have.

Thanks!

CeeSA · 26 Nov 2012, 15:23

I think I used a drill sized 6 or 8.

7bit · 26 Nov 2012, 15:35

CeeSA wrote:I think I used a drill sized 6 or 8.

7mm is the maximum I allow!