Toshiba RT2258TWUK: Interesting Rubber Dome

[Charlie_Brown_MX]

I came across this stuffed in a box when I was visiting my parents this weekend. In the name of keyboard science, I felt obliged to test its key feel, and was surprised to find it had what felt like a tactile bump. I pulled a couple of the caps to have a look, and found this:





(Apologies for the filthiness; I didn’t clean it before taking the photos.)

It’s an unusual configuration for a rubber dome; I haven’t seen any like this before. It looks almost like a hybrid between a rubber dome and a mechanical switch.

The model information from the back:



As rubber domes go, it felt pretty good, and there was a noticeable bump at activation point prior to bottoming out. The keycaps also have a small stabiliser of some sort. It was quiet, even when hammering the keys — I suspect that’s what the stabiliser was for.

[off]

As rubber domes go, it felt pretty good, and there was a noticeable bump at activation point prior to bottoming out.

Are you sure these activate before bottoming out?
On the matter of rubberdome with seperate switchstemthings, I've got one here with round 'switches' made by Tulip; good thing it used alps-compatible keycaps Shame that they used the model M method of stabilising keys, with a stick attached to the cap meant to slide into the 'switchplate'.

[ripster]

You get a LITTLE bit of travel afterwards.

Among the rubber domes the Individual Dome NMBs are some of the better ones. Thinkpads or Apple scissor switches also have separate rubber domes. Helps get rid of that "typing on wet newspaper" feeling.

[daedalus]

Looks almost identical to what is used in the Dell Quietkey. Someone around here had a DEC keyboard with something similar whose keycaps were compatible with Topre switches...

I'd suspect that these things were made when manufacturers were transitioning from microswitches to domes, either to save on retooling, or just out of a lack of imagination...

[off]

You get a LITTLE bit of travel afterwards.
Among the rubber domes the Individual Dome NMBs are some of the better ones. Thinkpads or Apple scissor switches also have separate rubber domes. Helps get rid of that "typing on wet newspaper" feeling.

I rechecked my variant yesterday, and indeed, after a clear buckle there is some slight travel left, feels like poking silicone though.
And NMB? "New methylene blue (also NMB) is an organic staining agent used in diagnostic cytopathology and histopathology, typically for staining immature red blood cells. It is a supravital stain.[1] It is closely related to methylene blue, an older stain already in wide use.
New methylene blue is toxic. Skin contact or inhalation should be avoided. It is available from a wide variety of commercial suppliers." I feel like I'm off on that one.

[002]

Rusty google-fu?

[off]

nah, this was lazy; went straight for wikipedia instead of context like gh/dt.
Still am though, care to share? ^^

[002]

http://deskthority.net/wiki/NMB

[off]

cheers. Was expecting either a type, like POS, or a construction method, not an OEM.

Spoiler:

These domes:



Expensive piece of painful typing experience btw, their latest. $250.- A goodlookin one at that though.

[huttala]

Looks almost identical to what is used in the Dell Quietkey. Someone around here had a DEC keyboard with something similar whose keycaps were compatible with Topre switches...

I'd suspect that these things were made when manufacturers were transitioning from microswitches to domes, either to save on retooling, or just out of a lack of imagination...

That someone is me , and I've found a lot of keyboards with switches just like the one TS shows.
Nothing special about them, I think they suck and threw them away.