I'm still around, and still gathering keyboards
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
Sadly life has made it more difficult to actually photograph and measure force curves...
Anyways, I have something special that just arrived from Japan.
An NEC DT-KCD2000C Type A keyboard. I'm not entirely sure what system it was used on.
![Image](https://live.staticflickr.com/65535/50498896098_305b652a09_6k.jpg)
Quite a bit of yellowing...
Fortunately the keyboard came surprisingly clean, so it lived in a pretty nice environment (though I did end up finding a small bit of rust on the springs so probably a humid environment too...).
![Image](https://live.staticflickr.com/65535/50499605676_9d60319ef5_6k.jpg)
All the keycaps are engraved then infilled. Normally keycaps like this are super gross when I get them, but with this board all I had to do was give them a quick wipe to get small bit of dust off.
![Image](https://live.staticflickr.com/65535/50499605616_a8822d64df_6k.jpg)
![Image](https://live.staticflickr.com/65535/50499605306_1edc9a4eb4_6k.jpg)
Mysterious red line.
![Image](https://live.staticflickr.com/65535/50499604201_54b75ddf98_6k.jpg)
That's a release button for the connector.
![Image](https://live.staticflickr.com/65535/50499604021_34af8afa18_6k.jpg)
The latch from the release button.
![Image](https://live.staticflickr.com/65535/50499759077_f2402a4c04_6k.jpg)
![Image](https://live.staticflickr.com/65535/50499758787_a5491ef0f1_6k.jpg)
July 1975. If I'm reading that correctly, the serial number is 15!?
![Image](https://live.staticflickr.com/65535/50498891798_9307b83863_6k.jpg)
Are those Alps Magnetic Reed Switches!? (wiki/Alps_Magnetic_Reed)
Only the rarest switch I know of (besides mercury filled tube switches of course, because those all had to be disposed of due to fear of mercury poisoning leaking out of the rubber tubes...
![Shocked :shock:](./images/smilies/icon_eek.gif)
![Image](https://live.staticflickr.com/65535/50498891413_4016ea5e54_6k.jpg)
![Image](https://live.staticflickr.com/65535/50498892463_79e4f63e22_6k.jpg)
![Image](https://live.staticflickr.com/65535/50499602511_13deff8d36_6k.jpg)
Interesting, the keycap mounting has an additional metal piece to hold the keycap in place (the caps are hard to pull off...). For reference https://flic.kr/p/fSWYGb
[url=https://flic.kr/p/2jWusqV]
![Image](https://live.staticflickr.com/65535/50499757197_22da7d3af4_6k.jpg)
![Image](https://live.staticflickr.com/65535/50499756572_3cd0b7691e_6k.jpg)
Inside sticker (same serial number and date code).
![Image](https://live.staticflickr.com/65535/50499600306_16aaef56d4_6k.jpg)
I believe (not confirmed yet) that the top right section is a resistor matrix that defines how each of the keys are mapped.
![Image](https://live.staticflickr.com/65535/50499596591_e01df4a20f_6k.jpg)
![Image](https://live.staticflickr.com/65535/50499595356_7fb93cd4d2_6k.jpg)
Interesting looking diodes and resistors.
![Image](https://live.staticflickr.com/65535/50498883478_65a6899d83_6k.jpg)
Alps sticker (interestingly enough, the pcbs were done by NEC which is unusual for Alps keyboards of this era).
![Image](https://live.staticflickr.com/65535/50499750142_cbbaa1452c_6k.jpg)
![Image](https://live.staticflickr.com/65535/50498883638_8acf51fdca_6k.jpg)
![Image](https://live.staticflickr.com/65535/50499749352_3f9337023e_6k.jpg)
Each row is numbered (not your standard switch plate).
![Image](https://live.staticflickr.com/65535/50499748487_2edaef4cee_6k.jpg)
Wait just one second! That's a magnetic reed switch...but it's not the same one?!
So now there are two unicorn Alps Magnetic Reed switches...and I have both of them
![Twisted Evil :twisted:](./images/smilies/icon_twisted.gif)
![Image](https://live.staticflickr.com/65535/50499592191_557d90d1f7_6k.jpg)
The reed seems to be attached to a mini pcb of sorts.
![Image](https://live.staticflickr.com/65535/50499745467_1e7065275f_6k.jpg)
![Image](https://live.staticflickr.com/65535/50499589716_8e1358a2b3_6k.jpg)
This mini pcb does make the pins quite a bit easier to solder/desolder.
![Image](https://live.staticflickr.com/65535/50499590416_19ce0b94e9_6k.jpg)
This new variant of the Alps Magnetic Reed Switch also doesn't have an integrated diode (reference https://flic.kr/p/fSXWM7). And also doesn't have an option for a 2nd magnetic reed (instead of the diode).
![Image](https://live.staticflickr.com/65535/50499589326_40ce271f35_6k.jpg)
![Image](https://live.staticflickr.com/65535/50499744432_24a3e89af1_6k.jpg)
![Image](https://live.staticflickr.com/65535/50498877628_947a36596f_6k.jpg)
The spacebar switch is heavier than all the other switches. Unfortunately I wasn't able to safely open the switch as the top housing is an extremely tight fit (might as well be a plastic weld). The first switch came apart by accident when I was pulling off a keycap at an angle.
![Image](https://live.staticflickr.com/65535/50498876008_5d8dfed421_6k.jpg)
These switches can be opened without desoldered, but I don't really see the point unless you're trying to clean out the switch or swap out the spring. From my experience with reed switches, is that the reeds are the most fragile part of the switch and they are soldered in... (and tbh, I haven't seen that many failed reed switches).
Full album: https://flic.kr/s/aHsmRzhC6r