Sorting out Hall effect switches

[Wendell]

Available information on Hall effect switches in keyboards is pretty sketchy. There is a lot of implied knowledge in past threads and it would be good to collect it here.

For starters, except for the modern RAFI board, I can't find any reference to a keyboard using Hall effect switches from anyone except Honeywell Micro Switch. Are old Hall effect switches from them?

I don't see much description of switch action, except that they are smooth and linear. How high was the typical actuation point? How well defined and consistent was the actuation point? How hard and noisy was the bottom/top out?

It is said that quality went down after around 1980. What changed? Did any models of keyboard span the change so that you can find ones with old or new style switches?

Some people have mentioned even some old Hall effect switches as not being as nice as others. How did they vary and in what keyboards did you find them? Can you identify them by model numbers on the switches?

I'm surprised at how few usable Hall effect keyboard models I can find, so far only these:
Burroughs TP130
Prime PST100 (just guessing here)
Symbolics LM-2 (Space Cadet)
Symbolics 3600 (Rev A, not Rev C)

Any more?

[webwit]

Four of them at the keyboard party!



I still need to research mine more...

Not a big fan of the key feel, I like tactile more. But if you like linear, they are very smooth.

[Daniel Beardsmore]

There are additional keyboards listed on [wiki]Honeywell Hall Effect[/wiki]; not sure whether they meet your "usable" criteria.

[Muirium]

The rise and fall of Honeywell Hall Effect is a story I've heard in fragments here and there. It could really use documenting. I was talking with Dorkvader about a 1983 model I've been playing with (and characteristically procrastinating over posting about and adding to the wiki) which has the smoothest key feel I've tried and wonderful caps, but a disappointing plastic stab under the space bar.

Yeah, the 142-key I have had a plastic spacebar stabilizer. The "vintage" ones use two dummy switches at each end and metal inserts in the spacebar ride on a nice metal wire. it's much nicer than the plastic spacebar stabilizer I have. I suspect they might have started using that in 1979-1981 when they switched over to the "modern" switch design.

Needless to say, I'm yet to try such a vintage version. And the Honeywell I have isn't hooked up to anything, so I can't answer for switch activation point either. But all that said I have to emphasise it is a supremely smooth keyboard, without much issue over off-centre key presses. The switches and their sliders in particular are just so physically large that there's likely less leverage for off centre hits, even with those monster caps! Cherry MX and Alps switches both look like miniaturised creations from the future next to (not quite so) Micro Switch.

I'm eager to bring it back to life, and can only wonder at what superior ones might be like!

[dorkvader]

Did somebody call?

As far as hall effect, I know of only a few others. Vintage HP used a sort that's similar to the newer RAFI ones, but I don't know much about them. I have found at least one reference to an IMSAI (not the IKB-1 though) that used hall effects.

Of the honeywell (Microswitch) they are split into two types. I call them vintage and modern, with the changeover being somewhere between 1979 and 1981. Modern ones are the ones predominantly featured in the wiki article, and have squared-off stems with the model number printed on the top. Vintage ones feature a mounting plate that attached to the PCB and has these flanges that split up and hold the key housing in place.

The activation point, I believe is listed in the datasheet (2.0mm out of 4.1mm throw), and is about halfway down (measured with an oscilloscope).

I don't know about quality going down after the change to "modern" My worst hall effect KB is a heavily used one from 1976, and my nib bud keypad with modern ones is excellent and linear. The modern ones are a little less wobbly from what I can tell.

Due to great differences in the mounting requirements, I seriously doubt there are any kb's that have both vintage and modern switches.

There is one keyboard with clicky tactile hall effects. These are based on the "modern" type and they somehow fit a tactile mechanism in the same switch housing! It is tactile on the way down and clicky on the way up. as far as I can tell, I have the only ones. Once I'm settled into my new apartment, I'll be passing them around the community (most likely on GH, 'cause hall effects get more attention there). The feel varies greatly between switches, sadly.

Then of course RAFI switches that use a buckling rubber sleeve as the spring are tactile. A mess of them showed up in Canada awhile back.

Of my hall effect boards, I have one from 1977 with tripleshot keycaps, and one from 1976. These most probably came out of unknown honeywell terminals and are just keyboard assemblies. I then have a "fisher rosemount" hall effect board. I'm not really sure of the branding, as the ebay seller listed it as that. It's the 142-key one with tactile switches.

I still need to research mine more...

That's not the only thing you need to research more. I found the exact IBM part number of that "Rojon" keyboard you have.

Spoiler:

It was clear from the pictures that it's a 66-key from a 3277 terminal, but after some looking in an IBM manual, I determines that it is a type B (and not a type A) keyboard. More looking verifies that it is an ASCII version, with textured (not smooth) keycaps. The PN for this configuration is 1825031. You should start calling it by it's real name, or at least "IBM 3277 66-key ASCII type B keyboard" or similar.

It was bugging me that you refer to it as "rojon". The key information linking it to a typeB and not typeA is the cable's part number

[Wendell]

Four of them at the keyboard party!

I see the RAFI, Symbolics Rev A, and Space Cadet. What is the other?

[Wendell]

There are additional keyboards listed on [wiki]Honeywell Hall Effect[/wiki].

I couldn't find any description of these, so hesitated to list them.
TI Telex 58SD17-2-B
Convergent 64-00164
Intergraph 2710

Anyone have photos and specs?

[Wendell]

... I was talking with Dorkvader about a 1983 model...

Since there are so few of them, we ought to just go ahead and give the names when talking about these.

[Wendell]

The activation point, I believe is listed in the datasheet (2.0mm out of 4.1mm throw), and is about halfway down (measured with an oscilloscope).

The Micro Switches seemed to have had an interesting force profile. Ripster measured some as being 50g at actuation but 100g at bottom. That sounds really comfortable. Was a force profile like that common?

Then of course RAFI switches that use a buckling rubber sleeve as the spring are tactile.

What? Do the RAFI switches use a dome, kind of like Topre?

[dorkvader]

A good staring point is the deskthority wiki article
http://deskthority.net/wiki/Honeywell_Hall_Effect

I only have examples of "normal force" and one of my clicky ones, the click mechanism has failed, leaving it a low force linear.

The keyswitches are commonly described as being " very linear", which is essentially true, especially for less well used, or recently lubricated units. The force displacement curve should be almost straight, as there is only one spring (cherry switches have two springs)

Typing on it was very dependent on off axis hits, I suspect lubricating the round stems, or replacing the switches with newer ones will help.

From what I have been able to gather, you can get RAFI switches with either a spring or a dome (technically a buckling rubber sleeve, like in some IBM keyboards) to provide the force. One user replaced the domes with springs, and reported success.

This is in no way like a Topre, as Topre uses actual domes and measures changes in capacitance. For the dome version of the RAFI switch (If I recall correctly) the dome just holds the key up and provides the force. It's the same functionally as using a spring, except less reliable, and tactile instead of linear. I've not tried it, but I think you don't have to bottom out. A user with one of theses keyboards surely could give you more info.

What do you mean by the following:

Since there are so few of them, we ought to just go ahead and give the names when talking about these.

There are tons of hall effect keyboards, with many different configurations. It's a safe bet that most (if not all) of the honeywell terminals from the 1970's and early 1980's have microswitch keyboards in them. It's just that they are less common than other keyboards. You can find a short list of some of the known devices with these on the DT wiki, linked above.

[Muirium]

we ought to just go ahead and give the names when talking about these.

Indeed!

At first I couldn't ID this at all:

IMG_0944-.jpg (372.13 KiB) Viewed 6657 times

Asking around, 7bit found a similar looking Honeywell and Dorkvader found the exact match. I still don't know exactly what the keyboard is called, but here it is with two different Honeywell systems:

Honeywell BO1810

The one I'm looking after is complete and its chassis looks just like this, only dirtier!

Honeywell BTRM 121C-001

$(KGrHqR,!rQFHZ5f,ocbBR8qD1jmGw~~60_57.JPG (336.13 KiB) Viewed 6657 times

(The eBay seller kibutzblackbear gave me permission to use his pictures with credit.)

There is just a single measly label on the exterior of the keyboard (in my case) which gives no name. So its exact title is unknown for now.

[dorkvader]

Four of them at the keyboard party!

I see the RAFI, Symbolics Rev A, and Space Cadet. What is the other?

Just to answer this, cause I don't remember if I did or not, there appears to be a burroughs between the rafi and the space cadet.

[webwit]

It's 7bit's, he'll know for sure.

[HaaTa]

dorkvader has sort've overtaken me as the authority on Hall Effect keyboards (been vacationing too long, but that's ending soon ). I've actually stayed away from Honeywell stuff recently, but it seems there are still some interesting variants around

But, I still have a bunch of keyboards in my collection that haven't been mentioned yet that are indeed Hall Effect.

From what I've seen, there are 2 types of hall effect switches in use (reed switch doesn't count, but I have a bunch those as well): Honeywell (transistor), and ITW (ferrite). I call the ferrite version ITW, as they hold the patent for this type of switch (Cortron lists it on the keyboard) and every single example I have is very similar in the design of the magnetic part of the switch.
There is also a clone Honeywell switch that I do have, I just haven't been able to take a look at yet (soon ). I also may have some other hall effect switches that I'm not familiar with yet, but no pics...

Honeywell Keyboards that I have:
https://plus.google.com/photos/11384566 ... 4082633025 (also the oldest keyboard I own, NIB)
https://plus.google.com/photos/11384566 ... 6120852081
https://plus.google.com/photos/11384566 ... 4152137793
https://plus.google.com/photos/11384566 ... 3040971441
And of course the Bud Keypads that I sold for a little while

ITW style keyboards I have:
https://plus.google.com/photos/11384566 ... banner=pwa (Xerox/Cortron, RAFI mount)
https://plus.google.com/photos/11384566 ... banner=pwa (Sperry Univac/Cortron, Honeywell Mount)
https://plus.google.com/photos/11384566 ... banner=pwa (HP, would probably fit on Futaba switches, this one is debatable if it's ITW and not related to Cortron I think)
https://plus.google.com/photos/11384566 ... banner=pwa (Univac/Cortron, looks like a Honeywell Mount, can't remember but I think it's smaller)
https://plus.google.com/photos/11384566 ... banner=pwa (Univac/Licon[became Cortron], same switch as above)

[HaaTa]

Yeah, the keyboard is a Burroughs, but really just a rebranded (recolored ) version of the Convergent keyboard for CTOS. I have one of the original Convergent keyboards in the above links.

[HaaTa]

I'll have to measure again, but the heavy version of the Honeywell Hall effect switch (modern ones) was about 320g, I think, when Ed Matias used the digital force gauge I brought to the Toronto GH meetup at Matias (it was something ridiculous). Unfortunately I didn't have a proper stand at the time...
Once my lab is setup, I'll take another measurement.

[Daniel Beardsmore]

That HP 02645-60023 has switches that look awfully similar to the ones in ITW's patent:

http://www.google.com/patents/US4099176

I can't see any differences between the two of any apparent significance. (Obviously they changed the keycap mount, but not a lot else.)

[Wendell]

I think most people who are curious about the Hall effect keyboards will never get a chance to try one. A better-than-nothing option would be to get hold of just some sample switches.

I saw here that Honeywell still makes them.
http://geekhack.org/index.php?topic=180 ... #msg789593

Anyone know the model number, how to get them, and how they compare to the old ones?