Smith-Corona Ultrasonic I Plus

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HaaTa
Master Kiibohd Hunter

13 Sep 2014, 20:18

If there is any keyboard that defines 2014, it's this one.
When I went to WierdStuff (Sunnyvale, CA) with damienG (mostly on GH), I bought this pleasantly clicky typewriter.
I wasn't sure what was in it, but didn't matter, it clicked :mrgreen:

ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr

It sat in my apartment for a few weeks until I had some time to figure out what really made it click. They typewriter worked perfectly, but I needed to dismantle it. For science :D
I'll leave the surprise till the end of the post, but try and figure out how it works just by looking at the pics. I nearly shat my pants when I realized it. :shock:


ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr

The simplicity of the controller is the first hint. Oh, and those big things, high wattage resistors.
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr

ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr

You've already seen the connectors to the keyboard. Your first guess, don't worry it's wrong. 8-)
The next pictures are just of the keyboard portion. Nothing is missing. This alone is sufficient to create a keyboard with a Teensy.

ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr
ImageSmith-Corona Ultrasonic I Plus by triplehaata, on Flickr

You've seen everything you need to know to figure it out.
Still not enough? Perhaps a video will help you ring some sense into it :lol:
Spoiler:
Cheater 8-)
Don't worry, most people don't get it right away.

Basically, this marvel of mechanical engineering is an "acoustic-sense" keyboard. It uses those little slappers on that hit the bar to encode a time difference that will hit the transducers on either sides. After that, it's super easy to figure out which key was pressed, hence the ridiculously simple controller for the early 80s.

The extra wires are for the keys you need to "hold". Yep only press with this keyboard. You'd need a double slap mechanism to make it work as a modern keyboard unfortunately.

Still think I'm BS? Lots of patents to back it up.
http://www.google.com/patents/US4364682
http://www.google.com/patents/US4376469
http://www.google.com/patents/US4378552
http://www.google.com/patents/US4381501
http://www.google.com/patents/US4384633
http://www.google.com/patents/US4407596
http://www.google.com/patents/US4430644

My presentation at Keycen West 2014 describes in a bit more detail on how acoustic sense works (https://docs.google.com/presentation/d/ ... sp=sharing).
Basically, as long as the transfer bar is designed correctly (and not vibrationally secure, notice the red rubber band things that are broken) the vibration/sound will travel across the bar. This pulse will hit the transducer. If tuned correctly for the right threshold, all the controller needs to do is time the difference between high points on each side (time difference of flight measurement/TDOA) which is essentially a scan code to lookup which key to "press".

At this point...I don't even think I can top the absurdity/awesomeness of this keyboard. Well...unless I start making keyboard switches :mrgreen:
https://www.flickr.com/photos/triplehaa ... 9444527936
Last edited by HaaTa on 25 Nov 2014, 23:31, edited 1 time in total.

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rindorbrot

13 Sep 2014, 20:20

It's one of these days where HaaTa spams the Pictures subforum, those are great days!

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Nuum

13 Sep 2014, 20:48

Those days really are great, especially when something like this comes up, with such a weird activation mechanism.

nourathar

13 Sep 2014, 21:06

excellent !

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BlueBär

13 Sep 2014, 21:20

That's an amazing mechanism :shock:

Hak Foo

22 Nov 2014, 07:07

Side note... I recently found an Ultrasonic II Dual Pitch at the local thrift shop. It looks very similar externally, but the key mechanism is definitely different. The cap stems are cruciform, there's a spring under each cap, and it gave me the distinct impression of a noxious VIC-20 style board. From feeling underneath it, it's definitely nowhere near as thick as the assembly you have. I haven't figured out how to disassemble it (since I sort of wanted it AS a typewriter), but I don't think it uses the same exotic mechanism.

Interestingly, a handful of keys-- those which are likely to auto-repeat, like period and space bar-- appear to have discrete switches. They're all white, linear, no exposed spring-- the overall look is sort of like SMK Vintage Linear, but the stem is cruciform, but the horizontal part is about twenty percent narrower than the vertical part,

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