Turns out I was in for a surprise
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
![Image](https://c5.staticflickr.com/6/5559/30563072100_7c093d0269_b.jpg)
The inside of the keyboard was made by a company called Digitran (seems they still exist too, http://www.digitran-switches.com/).
![Image](https://c6.staticflickr.com/6/5680/30776344581_ea0901f398_b.jpg)
Looking at the switch, assembly, my guess would be linear. But according to the force curve, it's a bit more interesting than that.
![Image](https://plot.ly/~haata/226.png)
Then looking at the bottom of the pcb...
![Image](https://c7.staticflickr.com/6/5745/30232440214_15f5e05697_b.jpg)
It took me a little while to realize that this is a capacitive switch, where one of the electrodes physically moves. This is in contrast to nearly every single capacitive sensing keyboard switch (except for this one photos-videos-f64/teletype-40k-104-dab-t6594.html).
Conveniently, there are even patents listed on the pcb.
https://patents.google.com/patent/US3750113A (NKRO scanning)
https://patents.google.com/patent/US4408252A (Switch)
https://patents.google.com/patent/US4412754A (Low-profile spacebar assembly)
For 1983-1984, Digitran did really achieve a low-profile keyboard, compared to a lot of other keyboards of the time.
The keycaps are mostly (crap and thin) doubleshot ABS. Though there are a few engraved/infilled keycaps as well.
But enough talk, more pictures.
![Image](https://c3.staticflickr.com/6/5519/30563074370_14df1265c5_b.jpg)
![Image](https://c2.staticflickr.com/6/5631/30228685793_f369a289d6_b.jpg)
![Image](https://c4.staticflickr.com/6/5515/30864301195_5fba0b9e0d_b.jpg)
![Image](https://c6.staticflickr.com/6/5587/30228700693_4189c96206_b.jpg)
![Image](https://c2.staticflickr.com/6/5549/30228713193_ddce93c904_b.jpg)
![Image](https://c8.staticflickr.com/6/5778/30228706303_906147954c_b.jpg)
![Image](https://c3.staticflickr.com/6/5739/30563101330_9b2a082b4a_b.jpg)
![Image](https://c2.staticflickr.com/6/5813/30776100001_98e8aea9f0_b.jpg)
![Image](https://c1.staticflickr.com/6/5726/30827895216_5bfd82edab_b.jpg)
![Image](https://c7.staticflickr.com/6/5746/30232144654_d4bc04bcca_b.jpg)
![Image](https://c3.staticflickr.com/6/5565/30827871026_55be1c4e6b_b.jpg)
![Image](https://c4.staticflickr.com/6/5551/30776137531_537dd39491_b.jpg)
![Image](https://c4.staticflickr.com/6/5340/30776172571_614ce155b0_b.jpg)
![Image](https://c2.staticflickr.com/6/5675/30776183961_02d532bb33_b.jpg)
![Image](https://c4.staticflickr.com/6/5332/30228866963_72ce8f95b3_b.jpg)
And yes, that's a Radio Shack key.
![Image](https://c6.staticflickr.com/6/5587/30864476685_2900fe3088_b.jpg)
![Image](https://c4.staticflickr.com/6/5484/30776296771_fed36ac087_b.jpg)
![Image](https://c3.staticflickr.com/6/5781/30232385474_590ac2d47f_b.jpg)
![Image](https://c2.staticflickr.com/6/5701/30864461505_963e8d09b0_b.jpg)
![Image](https://c7.staticflickr.com/6/5341/30828040406_1572ebcdd3_b.jpg)
![Image](https://c7.staticflickr.com/6/5758/30563357990_33770d120f_b.jpg)
![Image](https://c1.staticflickr.com/6/5573/30563361600_7f563e4076_b.jpg)
![Image](https://c7.staticflickr.com/6/5802/30563365550_f895aede7f_b.jpg)
![Image](https://c5.staticflickr.com/6/5496/30828077476_c227d00bf1_b.jpg)
![Image](https://c3.staticflickr.com/6/5781/30828083066_1c0ea3d5f1_b.jpg)
![Image](https://c8.staticflickr.com/6/5597/30864621935_09259eed69_b.jpg)
![Image](https://c4.staticflickr.com/6/5750/30864633715_e4a79d419f_b.jpg)
![Image](https://c2.staticflickr.com/6/5640/30864630185_5dd1bb5307_b.jpg)
![Image](https://c7.staticflickr.com/6/5669/30232443614_60fc361635_b.jpg)
![Image](https://c2.staticflickr.com/6/5512/30864648745_8606701a56_b.jpg)
![Image](https://c6.staticflickr.com/6/5587/30864654765_a1ca879b0e_b.jpg)
![Image](https://c6.staticflickr.com/6/5598/30776444821_a4b5cf71ec_b.jpg)
Flickr Album: https://flic.kr/s/aHskGLThEK