Honeywell Micro Switch Keyboard+Switch Teardown

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Offtopicthority Instigator

25 Mar 2015, 15:06

mr_a500 wrote:
mr_a500 wrote: I don't know why I didn't look carefully at the switches in this keyboard before. This is a strange version of the Micro Switch, maybe the original version before the "cage" with cylindrical slider with square mount. This keyboard is 35th week of 1970 - and HaaTa's is the 12th week of 1970, but his has the "newer" switch. (some overlap in the crossover?)

So, theoretically, Micro Switch went from the original version to the "cage" version in 1970 and from the "cage" to the irregular rectangle slider in 1977.
(quoting myself again...)

It looks like there was overlap going from the "cage" to the metal plate version too. I saw a 1979 keyboard that has the "cage". So you can get an estimate of Micro Switch keyboard age by the design, but there's room for error.
I'm pretty sure they did not produce those puppies in really high numbers back then and more in commission like mine from 1976 for IBM. But we don't really know and probably never will know for sure. So an overlap would not suprise me at all. I bet the "leaf-cage" variation was more expensive in production though.


30 Apr 2015, 17:00

In my research, I've found that nearly every major mainframe computer company used Micro Switch - the BUNCH (Burroughs, UNIVAC, NCR, CDC and Honeywell, of course) and even IBM (in that odd keyboard of yours, seebart) - though I haven't confirmed CDC used Micro Switch. That Sanders 720 (now famous as a Deskthority header) was also Micro Switch.

Key Tronic claims to be #1 keyboard manufacturer in 1978 with Micro Switch a close second. I'll bet Micro Switch was a clear leader in the years before 1978.

By the way, there's currently an NCR Micro Switch keyboard on eBay - NOS! (but expensive at $325 US)
NCR Micro Switch.JPG
NCR keyboard.jpg


28 May 2015, 18:53

I have proof that Micro Switch also made keyboards in Canada!
Micro Switch Canada.JPG
So we made beam spring and hall effect keyboards - two of the best. (sadly, now we make fuck-all)

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28 May 2015, 19:02

Oh that NCR is nice! But too $$$ for me at the moment. Good research. I got a couple of old Rafi's coming in, I'll keep you posted.


28 May 2015, 19:04

Yeah, that NCR is massively overpriced. I think the sellers have caught on that Micro Switch is a desirable keyboard.

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28 May 2015, 19:08

They might not even know exactly what it is, but once they see other auctions they get greedy.

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28 May 2015, 21:17

umm link to the NCR auction please?


29 May 2015, 21:47

It appears to be gone. I don't think anybody bought it at that price though.


09 Jun 2015, 14:01

I have connected that ASCII keyboard as a serial port using a Teensy. There aren't quite enough keys for it to be a modern keyboard. As you can see, it is not identical to the (US English) one in the CHM. ; / + is Ñ, generating # / ~; ; is moved to Shift-3 in place of # and + to Shift-uparrow in place of ~.

I have scanned the technical documents that came with it. These also indicate that it came from Godbout, so perhaps it was sold for use with some early personal computer, rather than as a spare for a Latin American NCR terminal.

The 28-pin SW-20306 MCU, presumably a custom-masked AMI of the period, is wired substantially the same as the SW-20276K.

I suspect those made in Canada keyboards with late 70s date codes that are showing up on eBay are also similar, with MOS -12V on pin 28 of SW-20365K, which only otherwise goes to the ribbon connector. This based on +5V and GND, as used by the switches and the MC-846P, being in the same places, 26 and 27. But I haven't seen any documentation and don't even know what model Burroughs system those were taken from.

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09 Jun 2015, 14:05

awesome work MMcM ! Thanks for the scan.


16 Oct 2015, 22:00

This seems to be the thread about "Micro Switch history", so I'll use it to post this photo I've found - supposedly from 1968:
Micro Switch 1968.JPG
Notice the switch cases. They appear to be like in Pyrelink's keyboard (this thread).

Also notice the flat squares. I've seen similar flat squares on Sanders terminal keyboards from around this period - for unused keys. Late 60's Sanders keyboards are known to be Micro Switch (from the manuals). These don't appear to be from the Sanders 720 though.


03 Nov 2015, 15:39

Continuing with Micro Switch history...

Now I can see the point of the metal bit in the keycap:

Micro Switch keycap.JPG

It looks like it's a keycap adapter! Two of the earliest keyboard makers were Micro Switch and IBM. The metal bit (and the slider it fits into) allows Micro Switch keyboards to use IBM "Selectric-style" keycaps. ( keycaps of that shape were called at the time - other keycaps were UNIVAC-style or round Burroughs or Teletype style)

It doesn't seem to have been around for long, just 1968(?)-1970.
Last edited by mr_a500 on 03 Nov 2015, 15:45, edited 2 times in total.

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03 Nov 2015, 15:42

Hopefully someone can grab that early Micro Switch with this switch that macmakkara found in the UK just now.


03 Nov 2015, 16:07

I want it but i don't get paid until 14th and i would like to be able to eat.

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21 Nov 2015, 15:20

I'd like to continue here with pyrelink's permission. I think Engicoder found this a couple of weeks ago, I thought this was too interesting to pass up so I bought it. The seller has no information on it, apparently they got it from some decedent's estate.
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The case is metal all around. The case is quite bulky with the enclosure at the top and measures 42cm across, 20cm in depth, 8cm tall at the front and 16cm tall at the back and weighs 3154 gram. Looks insane next to my FC660C.
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The most disappointing thing is that I do not know who manufactured this, not sure if we'll find out. There are some serial numbers on the PCB. There are some handwritten notes and stamp markings on a piece of tape inside the top part of the case. There are two numbers handwritten inside the bottom part of the case reading "368" and "800210/68"
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The switch housings are screwed to metal rows which are in turn screwed to these steps inside the top part of the case with long screws. Hand wired, but in a professional way.
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The top of the switch housing reads "MICRO USA". These are the same switches as in pyrelink's keyboard, Micro Switch magnetic reed switches. The switch housing very conveniently opens via two small screws at the top, the red slider sits at an angle across in the switch housing, the little metal bit inside the red slider being the magnetic contact.As pyrelink noted there are different markings on the side of the switch housings,I can read "6949 7A1HS" and "6950 7A1HS". Both switches feel the same to me.The switch is linear,very smooth and uniform in feel, impressive if you consider the age (which I do not know but estimate to be early 1970's or late 1960's). On a subjective "best feeling vintage switch that I own" scale this switch is number two behind Micro Switch dual magnet hall effect.
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All the keycaps are engraved thick sphericals . There are visible imperfections on the engravings. The metal bit that goes into the slider does not come off on mine like it does on pyrelink's keycaps . These keycaps do not resemble my other Micro Switch keycaps at all.All single unit keys,"space" on the spacebar, also engraved. No return or enter key present,"New Line" instead."Tab" on the right hand side.There is no key stabilization, the spacebar is stabilized by two switches eight units apart instead.
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The top row large function switches are very different. They are clicky, quite loud and it looks like it may be a type of leaf contact mechanism.I can read the marking "MICRO USA 6947 7A1CA" on the side of the switch housing, the other side shows an electrical schematic.
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I shot lots more pictures if anyone wants more, as usual I'm reading
Cannot add another attachment, 15 is the maximum.
in the editor right now. :)
Last edited by seebart on 21 Nov 2015, 18:26, edited 1 time in total.

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21 Nov 2015, 16:33

Now that is an awesome looking keyboard. Clicky versions of that switch?! I am having a hard time figuring out how those switches click so more pictures of them would be appreciated. Did this board require an insane amount of cleaning to look as nice as it does or did it look pretty great to begin with? If I had to make an obvious guess, it would seem that someone else manufactured the keycaps with this specific switch in mind. The PCB and markings look very similar to a Honeywell Micro Switch board. Too bad there isn't a date code. Would be nice to know where this one fits into the timeline.
Last edited by pyrelink on 21 Nov 2015, 17:11, edited 1 time in total.

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21 Nov 2015, 16:40

Thanks, only the large function keys in the top row are clicky. The Micro Switch magnetic reed switches are linear. The keyboard was quite filthy on the outside, suprisingly clean on the inside. Yes I agree, I also think that someone else manufactured the keycaps. mr_a500 should take a look at this, he might be able to tell us more.

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21 Nov 2015, 16:50

Wow Seebart, that's goddamn beautiful. Amazing, thanks for the pics! :D

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Vintage computer guy

21 Nov 2015, 16:52

First off, that's an awesome keyboard! Thanks for posting the pics.
pyrelink wrote: Too bad their isn't a date code. Would be nice to know where this one fits into the timeline.
The key switches are from 69 probably 47th week (6947 is a date code). There is also an IC on the board with a date code of 7012 which would be 1970 12th week. It all points to 1970. My Univac keyboard has different switches and are marked "7110" (10th week of 1970) so they re very close.

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21 Nov 2015, 17:11

Oh wow, I didn't even realize that it was a date code on the switches as well. That would make sense as my keyboards' switches are 7030 and the date code on the keyboard is 7035.

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21 Nov 2015, 17:48

Well I'm glad you guys enjoy it. ;) That's some good information snuci, thanks. If it's from 1970 then it's my oldest keyboard by far. But what about the shape of the case snuci? You think it may have been for some terminal?

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Vintage computer guy

21 Nov 2015, 18:01

seebart wrote: But what about the shape of the case snuci? You think it may have been for some terminal?
I'm not sure. It may be for a paper based terminal (as opposed to a CRT terminal) or a teletype device but it is definitely something paper based due to the "Print" key. It has a ETX or "End of Text" key that was used to tell the remote computer it communicated with that it has completed sending the message. Looks like the device could record a message as well.

It is interesting but because it's from the early 70's it is just before most CRT terminals.


30 Dec 2015, 22:52

I had a photo of this exact teletype (or very close), but I've lost it somehow. Snuci is right. It's from 1970. (keycaps probably not Micro Switch)

More Micro Switch history. Check out this ad from April 1970:

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Offtopicthority Instigator

30 Dec 2015, 22:59

Nice ad. I still find Micro Switch Hall Effect slightly smoother than Micro Switch Reed switches. To me what's at least as interesting as the switch on this one is the unusual shape of the case and the fact that all the keycaps are engraved.


30 Dec 2015, 23:07

Sadly, I have never had Micro Switch reed switches to compare. I have four 1974 Micro Switch keyboards, but nothing earlier.

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30 Dec 2015, 23:12

Oh don't get me wrong, they feel very nice to type on. Strange that the metal adapter bit in the keycap does not come off on mine. Also these keycaps look very different from all of my other Micro Switch caps. I'm wondering if this even is a Micro Switch keyboard, apart from the switches we don't know.


30 Dec 2015, 23:17

As I said, your keycaps are probably not Micro Switch - probably some European supplier.

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30 Dec 2015, 23:20

Right, I did buy it in the UK after all, but the seller could not tell me anything about it. Certainly the most unusual vinatge keyboard in my collection. Also the oldest.

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31 Dec 2015, 15:45

Well, that's two hours of my life I'll never get back. I scrounged the net like a fanatic solidly for over two hours and never did see anything like it. Very interesting.


31 Dec 2015, 15:54

Actually, you can get those two hours back, but only if you're Superman and you fly around the Earth really fast. Then you can (inexplicably) spin the Earth in the opposite direction which somehow turns time back. I've never actually tried it myself.

I just searched too and the only interesting thing I found was this picture of the Queen trying out a terminal:


I wonder if she liked the keyboard.

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