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geekhack Community => Input Devices => Topic started by: xwhatsit on Mon, 01 August 2011, 21:13:58

Title: Trackpoint from laptop keyboard
Post by: xwhatsit on Mon, 01 August 2011, 21:13:58
Hello all,

Would love to mod a proper IBM trackpoint (or the Dell one isn't bad either) into one of my Model M or F 122-key terminals. I understand the Unicomp one is a bit rubbish.

Seems quite difficult to obtain the trackpoint module on its own. So I looked at those Thinkpad USB keyboards, but most seem pricey. However, I see plenty of replacement Thinkpad laptop keyboards (just the sheet of scissor switches, with a trackpoint in the middle) very cheap. Do these contain all the logic for the trackpoint? Or are they just dumb sensors? It would seem a big chunk of what makes the trackpoint good is down to clever firmware; I don't really want to try replicating it.

Here's an example: http://cgi.ebay.com/IBM-THINKPAD-R60-R61-T60-T61-Z60-Z61-KEYBOARD-39t7118-/170674205394?pt=PCA_Mice_Trackballs&hash=item27bcf9b2d2
Title: Trackpoint from laptop keyboard
Post by: hasu on Fri, 05 August 2011, 12:30:58
ThinkPad's TrackPoint Unit is just a complete 3-buttons PS/2 mouse.
It has a 'logic' on TPM754 controller chip with firmware. No problem electrically.
Finding a good long stem for the unit is the problem. See zmurf's mod.

I look forward to seeing your mod.


You can find info about TrackPoint here:
http://geekhack.org/showthread.php?8971-Looking-for-Trackpoint-controller-IC-pinout

zmurf's mod:
http://geekhack.org/showwiki.php?title=Island:11420

another TrackPoint mod:
http://translate.google.com/translate?hl=en&sl=zh-TW&u=http://aries.armake.com/1229.html
Title: Trackpoint from laptop keyboard
Post by: xwhatsit on Fri, 05 August 2011, 21:44:35
Wow, awesome! Thanks for the links. That doesn't look too hard, then. Will have to order one of these laptop keyboards then!
Title: Trackpoint from laptop keyboard
Post by: TexasFlood on Fri, 05 August 2011, 22:20:38
Yes, thanks, I remember that first link but didn't find it again in my first search.  Bookmarked it now.