Another Data General 6246-A

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07 Oct 2019, 20:14

I picked this up a while ago and finally got around to working on it. I've seen some others on here and thought they looked pretty cool. This one is also a Fujitsu 3rd gen leaf spring, so hopefully that means they all are. It was in pretty good shape.
Case_Front_Orig_SM.jpg (366.4 KiB) Viewed 174 times
Case_Back_Orig_SM.jpg (205.18 KiB) Viewed 174 times

Opened it up:
Open_Orig_SM.jpg (463.07 KiB) Viewed 174 times
KB_Assy_SM.jpg (375.87 KiB) Viewed 174 times
Keys_Off_SM.jpg (387.01 KiB) Viewed 174 times
PCB_Back_SM.jpg (241.66 KiB) Viewed 174 times
PCB_Front1_SM.jpg (427.43 KiB) Viewed 174 times

I desoldered the ribbon connector and traced out the matrix to wire the Teensy 2.0++. Pins 0-6 were the columns with diodes, 8-23 the rows. Pin 7 was not connected to any board traces.

wires_SM.jpg (283.96 KiB) Viewed 174 times
Teensy_SM.jpg (333.99 KiB) Viewed 174 times

I did manage to lift a pad - hence the yellow bridge wire. Can also see lifted part of pad on pin3. I'm "OK" at soldering for the most part but this board did seem a little touchier than most.

Then reattached the upper PCB and closed it up.
Teensy_in_SM.jpg (590.47 KiB) Viewed 174 times
finished_SM.jpg (352.86 KiB) Viewed 174 times

I did go back and wired the LEDs for lock lights, and speaker to the Teensy. I'm not sure what the speaker was originally used for but I used it to provide key beeps - with a toggle switch so I don't have to listen to it all the time!

Here's a short video of typing on it:

Also if anyone is interested, this is the matrix i came up with:
Matrix.jpg (273.69 KiB) Viewed 174 times

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07 Oct 2019, 21:17

Yeah, these are all 3rd Gen leaf springs IIRC. Great boards. And unlike the 2nd Gen, they have all the diodes integrated already which makes converting so much better. With your matrix now, someone could actually convert one in less than an hour if they knew what they were doing. Really great work as usual, dude.

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