Mitsumi Alps clone?

[Findecanor]

It appears that the Mitsumi Alps clone isn't really a clone of the Alps SKCM/SKCL.
The internal mechanism seems to be very similar to Alps, but to be a proper clone, it would have to be pin-compatible and plate-compatible and it is actually neither.
I suppose that it was called "Mitsumi Alps Clone" because it has Alps mount and was found in the AEKII where all other variants have Alps, and just assumed to be compatible.

One variant of the Amiga 1000 keyboard seems to have the same switch as the AEKII, but with a square Mitsumi mount hole in the middle of the H-shaped slider, and a black housing instead of white. The switch plate is blue, but so it is in the lock variant of the "Alps clone".
There are a couple of great images of the A1000 switch in this thread on Geekhack, which you can compare with this image of AEKII lock switch innards.
There are also images in this thread on Amibay, of which this image does not require login.

Regarding this, I think that we can conclude that the switch variants can be categorized as the same.
But what should we call it? The mechanism is similar, but it is not pin- or plate-compatible with Alps.

Also... this is definitely a mechanical switch. Should we not also rename the Mitsumi mechanical switch also?

[Daniel Beardsmore]

When I saw this topic, I figured you'd seen that GH topic.

Mitsumi is a bit of a pain. They liked a bit of chop and change:

Large shell, lateral spring: http://geekhack.org/index.php?topic=197 ... #msg389989
Large shell, vertical spring: http://www7.ocn.ne.jp/~hisao/image/ext2m.htm
Small shell, lateral spring: http://www7.ocn.ne.jp/~hisao/image/epsontenkey.htm
Small shell, vertical spring: http://www7.ocn.ne.jp/~hisao/image/burton.htm

It's interesting that they used all four combinations: large shell with a pseudo switchplate, and small shell with a lateral contact, each with a vertical spring and with a lateral "wrap-over" spring.

Plus there's the older variant of the large, vertical: http://www7.ocn.ne.jp/~hisao/image/plus.htm

I didn't realise that the "Alps clone" one wasn't actually interchangeable with Alps switches, so yes, it's due for a rename.

In terms of renaming "Mitsumi mechanical switch" — definitely, and probably split the page into whatever you want to call the "large" and "small" versions. We need a Japanese speaker to get some details out of all the elusive Japanese companies (Alps, Mitsumi, Futaba, SMK etc) as Japanese companies are really unhelpful.

Or even just a catalogue would give us the part numbers.

[Findecanor]

I edited "Mitsumi Alps clone" with info about the lateral spring variation, for now.
I wonder if the colour of the housing indicates lateral vs. vertical..

How does the lateral spring work, really? Are there pegs in the slider that holds it? People say it is linear, but does it feel different from the other? ...
We need more keyboards to figure this out!

[Daniel Beardsmore]

Maybe the Deskthority Club Master will appoint official Chinese and Japanese translators who can obtain all this information from people like MouseFan, rzwv, alps.tw and yab. A lot of information is out there, but is just hard to obtain.

[webwit]

Small chance. 1) No interest in the club master position so far and 2) If we get one, he'll try to appoint you as wiki master, where your duty is to appoint translators, among others.

Nice try, leprechaun!

[Daniel Beardsmore]

Wait, the club master will try to appoint non-members?

[webwit]

As long as club members don't vote for rules about that, there are no rules about that.

[Daniel Beardsmore]

That would be spiralling down a road of no worky, but it's also off-topic.

[Daniel Beardsmore]

Here's another one:

http://www.vintage-computer.com/vcforum ... mmodore-64

The Commodore 64C has a latching shift lock key, with a single Mitsumi ................. a Mitsumi thingamaswitch.

The rest of the keyboard is Mitsumi membrane. You can see the mechanical switch mounted into the plastic plate here:

http://bilgisayarlarim.com/Commodore/64C/

It's just unrecognisable in that photo. Also, note the hole in the PCB to accommodate the switch: the switch is pushed through that hole, and then its legs are soldered back up to the PCB!

I'll have to delay adding this to the wiki until the great Mitsumi switch reunification/rename is complete, as this isn't an Alps clone even if the Alps clone were an Alps clone ...

[Daniel Beardsmore]

More Mitsumi goodness:

http://sandy55.fc2web.com/keyboard/zkb-2.html

Small shell, with Alps mount sliders! So that's three different keycap mounts for the same switch (Mitsumi, Cherry MX, Alps).

Plus grey linear Alps.

[Daniel Beardsmore]

I've gone with [wiki]Mitsumi miniature mechanical[/wiki] for the little ones.

Not sure about the big ones. "Mitsumi standard mechanical"?

I am also not sure whether to classify the "Alps clone" style ones (also found on some Amiga 1000 keyboards: see http://geekhack.org/index.php?topic=19761.30 for some close-up shots) as being the same switch as the type used on old Apple keyboards:

http://www7.ocn.ne.jp/~hisao/image/plus.htm

They're similar internally, but also quite different-looking.

BTW, does anyone have an actual photo for the miniature type used in the Amiga 1000? It's listed on the wiki without a reference, and while it seems plausible, I can't find any photos of it. I suspect it's going to be Mitsumi mount, but I can't be sure.

[rzwv]

The MITSUMI switch attached to Apple TDK-T 12V is compatible with M3501.
There were a point of contact, lock structure, and compatibility with a plate.
http://kbd.rzw.jp/mitsumi_/apple_tdk-t12v/

[Daniel Beardsmore]

Thank you. That is interesting to know. So yes, they are in effect the same switch.

A couple of things I noticed:

1) Holes which appear to support DPST:

Old school -- possible support for DPST.jpg (24.44 KiB) Viewed 5361 times

Some Tai-Hao APC series switches have "reversible" lower shells, and I thought it was just done to ease manufacturing, by allowing the parts to be placed either way around. Maybe Tai-Hao once sold DPST switches too. DPST isn't all that common, but Cherry made them.

2) The old-school switches didn't have the little bumps that keep the switch away from the PCB (or whatever it is that they do):

''Alps clone'' PCB separator bumps.jpg (27.03 KiB) Viewed 5361 times

Does that affect the PCB-to-plate distance, or were the old switches slightly taller?


Now all the switch needs is a name.

[Daniel Beardsmore]

The MITSUMI switch attached to Apple TDK-T 12V is compatible with M3501.
There were a point of contact, lock structure, and compatibility with a plate.
http://kbd.rzw.jp/mitsumi_/apple_tdk-t12v/

That keyboard is from an Apple IIe Enhanced:

http://apple2history.org/history/ah07/

[rzwv]

Switches were actually exchanged.

TDK-T12V→M3501
The switch was expensive and was not fixed to the plate. The leg used as a point of contact has come out.

Spoiler:

Apple_TDK-T12V_25.jpg (574.21 KiB) Viewed 5333 times

Apple_TDK-T12V_26.jpg (423.71 KiB) Viewed 5333 times

Apple_TDK-T12V_27.jpg (455.78 KiB) Viewed 5333 times

Apple_TDK-T12V_28.jpg (517.59 KiB) Viewed 5333 times

M3501→TDK-T12V
The switch was low and was fixed to the plate. However, the leg used as a point of contact did not come out.

Spoiler:

Apple_TDK-T12V_29.jpg (560.59 KiB) Viewed 5333 times

Apple_TDK-T12V_30.jpg (531.36 KiB) Viewed 5333 times

Apple_TDK-T12V_31.jpg (706.11 KiB) Viewed 5333 times

http://kbd.rzw.jp/mitsumi_/apple_tdk-t1 ... DK-T12V_25

[Daniel Beardsmore]

Ah, so the PCB-to-plate distance is different between the two switches.