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geekhack Community => Keyboards => Topic started by: Pylon on Sun, 26 December 2010, 18:21:31

Title: How feasible would this be (rewiring ADB numpad to USB)
Post by: Pylon on Sun, 26 December 2010, 18:21:31

Hi,

So I managed to get an ADB-connector SMK-22 numpad for Mac, with complicated white alps. The thing is, I'm not interested in using it only on my old G3 and I could use a numpad for my laptop, so I'm thinking about converting it to USB.

So basically, I have some rubber dome USBs I could salvage a USB controller from. My plan is basically just to slice all the traces off the SMK-22 PCB and then wire the rubber dome controller's matrix over the switches, and then hook it up to the USB controller. Feasible?

Title: How feasible would this be (rewiring ADB numpad to USB)
Post by: Pylon on Sun, 26 December 2010, 18:29:22

My plan:

Original:(http://img155.imageshack.us/img155/1625/circuitspad.jpg)
By null (http://profile.imageshack.us/user/null) at 2010-12-26
After:(http://img218.imageshack.us/img218/9726/pcbpart2.jpg)
By null (http://profile.imageshack.us/user/null) at 2010-12-26

Sadly, the thing has diodes and thus NKRO, which I would lose with a blocking rubber dome controller.

Title: How feasible would this be (rewiring ADB numpad to USB)
Post by: bladamson on Sun, 26 December 2010, 19:41:01

I am working on doing this with the alpha section of an old platinum ][e keyboard at this very moment, actually. :P

I'm gonna break it out to a DB25 connector, and then put the controller from a broken Model M into a project box.  The project box will have several opposite gender DB25s on it, so that I can plug all of my hack 'em up keyboard matrix projects into it at once (as it looks like I have an apple std keyboard on the way too \o/ ).  Hopefully the M controller is beefy enough (I'm assuming it's all TTL lol) to drive everything and there won't be crosstalk.

I figure it'll be fine if I keep the cables under 4'.