More hall effect action!

[dorkvader]

I keep some cool eBay searches up. Rececntly, I came across this:
http://www.ebay.com/itm/390706320593
"Vintage Micro Switch SD 16240 Systems Rare Computer Keyboard Computer Untested"
The seller was nice enough to remove the case and take some interior shots, confirming microswitch hall effects.

Now, I noticed a few cool things about this.
1. Sculpted profile. I don't ahve any sculpted profile keycaps for microswitch
2. there are differently coloured legends on the homerow for some fractions or something

So I bid. No-one else bid. Sometimes I think I'm the only person watching eBay.


It arrived today via UPS (at like 7:30 PM)


Shaky picture of whole KB
This thing is huge! Probably one of my largest KBs (until I get a delivery scheduled for tomorrow). It's about as wide as two sheets of US paper (so about 21 inches). I guess it's about the size as an F122.




Keycap is beige. Legends are black and lightgrey. No idea why they went so low contrast on this one



More tripleshots! Sweet!


The lock switch is latching Pressing either shift releases it. Here's some pictures of the mechanism.

View from the top (locked down)



up



down


Blank key at the top has a blocker. You can press it about 0.5mm or less


Some noticeable differences in special stem types.

The shift key is "profiled". Notice the stem is angled. Pretty cool!. The extra dummy switch that stabilizes it is also angled and has a different part number. The "command" switch is flat profile (as is the 2x "data" key at the top) and has different "flat" stems that go on it.

I have lots of pictures of the case, PCB, chips, and other stems if anyone is interested, my imgur is getting full (I think there is a max limit to the pictures you can have) so I'm looking for a new image host for KB related pictures.

Yes, I will be cleaning the dirt off later.

Imgur album:
http://imgur.com/a/XPX4t

Cross posted at deskthority:
http://deskthority.net/photos-videos-f8/more-microswitch-hall-effect-t7010.html#p136356

Edit: Switch part numbers include

4A6B (only used for "reset" key)
4A3B (mostof the yellows)
4A3K (some of the yellows) (same as above..?)
T4A3B (Insert Space) (same as above two..?)
T4B3B (most of the alphas)
4B3K (some of the alphas ) (same as above..?)
4B3B (one of the alphas) (same as above two..?)

4A1B ("light" half for 2x yellow key and 2X command key flat profile)
6A1D (dummy half of above) grey body, blue stem
10B1A ("light" half of 2x right shift key, "latch" and "unlatch" support)
6B1D (dummy support switch for above) (grey body, black stem)

10B3a ("normal" weight for leftshift and capslock. "latch" and "unlatch" support)

Edit2: keyboard date code is 50'th week of 1979

[lcs]

Very nice!

How do hall effect switches feel?

[CPTBadAss]

Ugh. AGAIN you made me jealous with your tripleshot sexiness dorkvader. Very nice find

[dorkvader]

Very nice!

How do hall effect switches feel?

They are very linear.

The exception is the run of "clicky" hall effect switches I found in an industrial "Fisher Rosemount" keyboard which are clicky and tactile. On the way down they are tactile, sort of like a clear. The click is on the way up which feels a bit odd. I haven't yet found another keyboard with nonlinear hall effect switches, and I have 5 or 6 of them now.

Ugh. AGAIN you made me jealous with your tripleshot sexiness dorkvader. Very nice find

Compared with my other microswitch tripleshots, these are thicker (same thickness as normal caps) and the shots are more integrated. I guess they improved their process since 1977. One cap, however, is very thin. I guess it was replaced at a later date (several switches show signs of desoldering).

[Reomero]

Wow what an amazing find!

[Lastpilot]

Nice grab dude. Now you can be shifting like a boss!

[SonOfSonOfSpock]

Really nice! I like all the keys that aren't on modern keyboards.

[dorkvader]

Really nice! I like all the keys that aren't on modern keyboards.

My favourite are "Line Len'th" and "super shift".

I'm thinking this was used for document processing or printing, given all the typographic editing keycaps. em space en space, etc