NEC Spinwriter terminal, with Honeywell SD keyboard

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31 Aug 2020, 15:00

I was perusing Craigslist, and spotted an NEC Spinwriter printing terminal, basically a more modern teletype. After some cleaning and oiling, it works great!
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When I typed on it the first time, I was surprised how nice the keyboard was. No wonder... it has a Honeywell / Microswitch SD hall effect keyboard!
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Most of the keycaps with white plastic have yellowed. They did this on the underside too, so it doesn't seem like just UV exposure.
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The repair manual mentioned it's an ASCII keyboard, and looking at the schematic it wasn't hard to see where the data lines are on the connector. The 4 switches to the left of the keyboard have dedicated lines. I used a Teensy 2.0 and the Keyduino library as a starting point (
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The board will be going back into the NEC, but this was a nice Sunday project. I added some code to play a keyclick when the Local key is latched down. Auto Line Feed turns 5 123 into a D nav (also a latching key), and Break with the number keys makes function keys, with the bracket key makes curly braces, and with ESC launches Spotlight.

The weighting on these switches is on the high side for me, I normally use a Kinesis with Kailh BOX browns. But it's a nice experiment!



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08 Sep 2020, 14:59

Over the weekend I had great success whitening the keys. A friend suggested using just OxyClean. I had some OxyClean laundry gel.

I found it didn't touch the gray plastic, and did whiten the white plastic.

The DEL and \ keys were originally equally faded. The Backspace key was not faded. This is after about 2 hours in the sun, with a gel re-up at the 45 minute mark:
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Re-assembled! There's a very slight difference in color, but I'm happy. I didn't want to push it and risk damaging the caps.
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