deskthority

Snagged these two boards recently and have been working on cleaning up the smaller of the two.
They are both brother proto-topre. The KB-150 is dome over PCB and the smaller one (I think from a WP-500 or similar) is dome over membrane. Here is a before pic from the listing. Once I have these cleaned properly I'll post some after pics.


Now you would naturally assume that the membrane dome board is the worse of the pair but it is superior in my opinion. The membrane mechanism does not have a silicone mat of domes, instead consisting of individual domes adhered to the top membrane, and the membranes themselves are on top of a metal back place. This results in the slider bottoming out on the small retention clips that hold it in place instead of bottoming out on silicone. It has basically the same tactility but the solid bottom out gives it a more "mechanical" feel. Neither are bad boards but the KB-150 feels slightly mushier as a result of the dome sheets it uses.



While this 5.5mm nut driver that I have for model Ms does work, it is slightly too large. These are probably 5mm.



This is a dedicated keyboard and I assume that it speaks somehting but I don''t know what it would speak or if it has been converted. At either rate it is easy enough to read from the membranes and run it through a teensey so I will not be attempting to convert the protocol.


With sliders removed I can clean the top and bottom housings as well as the keys. The sliders are in good shape and are clean so I won't be cleaning them. The space bar stabilizers were caked in old grease so they have been cleaned. I'll put a dollop of dielectric grease on them when I reassemble the board. The membrane also looks clean which is nice, replacing that would basically mean getting a second keyboard.



The flip out feet are a really cool design but sadly they are broken. Looking at another model the feet appear to pull double duty as a hinge and I bet they broke off in the unit before the keyboard and the unit were separated.

Unlike the smaller board the KB-150 actually has a label on the back and a name on the front.




Like most other Brother typewriters and word processors these boards come with tripleshots but the KB-150 has a tripleshot backspace even though it only has a single legend colour. I haven't seen this before and it is super strange. I guess this was cheaper that making a doubleshot mold for the backspace?


The cable on this keyboard is pretty weird too. It looks like the board is basically a document printer that when paired with a dedicated printer is able to function as a typewriter or a word processer. I have seen this sort of keyboard layout and design on large brother typewriters so it looks like they left the type off the typewriter. I'm not entirely sure why this would be desirable. If I can get ahold of a printer (I think a wheelwriter would work as well) I will see if this thing works.
Here's some pics of the guts:









The feet on this give it some ridiculous angle, probably to match the angle of the typewriter. They are super stiff and make a loud snap as they flip into place, much better than the broken feet on the WP-500 board.




The sliders aren't clipped in like they are on most other brother dome boards and can be put in upside down if you really want, but the key stem is not reversible so doing this would really only be useful if you wanted a meme spacebar. On the enter key it looks like it is set up to have either the BAE that it does have or a 3u tall enter more in the style of an iso enter.

For this board it would also be fairly easy to wire up a teensey and convert it to USB, but since it should be able to print stuff I want to see if it works. Even if it doesn't, it is a very large footprint for not a lot of keys, less keys than the much smaller WP-500 board, so it wouldn't be as good to daily. If I can convert it in a way that it reversible I might do that just for the hell of it, but it will likely be either a looker or a donor board once all i said and done.

Very nice! These old Brother domes are the best I've ever felt; even better than BTC dome with slider and probably Topre (although I haven't tried it yet).


I may attempt to convert mine sometime in the future, but mine was integrated into a typewriter so I would also have to build at least part of a case. Amazing domes though, and the keycaps are the highest-quality I have seen in person...period.

Well, I’m quite willing to believe they could be very nice. But they're still membrane, in the end. That means full bottoming out is required. And that’s a different story from Topre.

Actuation at midpoint is a game changer in all mechanisms. Maybe not for everyone—plenty users just wanna mash!—but for those of us who like to tickle the keys.

Muirium wrote: 16 May 2020, 17:12 Well, I’m quite willing to believe they could be very nice. But they're still membrane, in the end. That means full bottoming out is required. And that’s a different story from Topre.

Actuation at midpoint is a game changer in all mechanisms. Maybe not for everyone—plenty users just wanna mash!—but for those of us who like to tickle the keys.

Ah, yeah, well I like bottoming out my keys like an idiot


The Brother domes just feel great, super snappy and I can't detect any mush.

Muirium wrote: 16 May 2020, 17:12But they're still membrane, in the end. That means full bottoming out is required.

As a point of order, this is incorrect. Membrane boards like the model M and boards with Acer switches do not require bottom out to actuate. (alps spring over membrane and smk spring over dome might not require bottom out either but I don't have any direct experience with them in working boards) And even dome and membrane boards could have actuation in the middle if the slider is designed properly.
These specific boards do require bottoming out but the force to do so and the dampening the dome provides prevents the bottom out from being overly harsh imo so its not a deal breaker for someone like me that generally bottoms out anyway.

Very nice! I've always been curious about these Brother Keyboards.