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[top]Introduction

There are three types of ALPS keyboard switches: "Bigfoot", low profile switch, and "leaf spring". They can be seen here: http://park16.wakwak.com/~ex4/kb/tech.htm

In addition, a buckling spring over membrane type mechanism was also made by Alps, originally for the Sega Teradrive system manufactured for Sega by IBM. It was later used in various other brands, particularly C.itoh clones of the DEC LK201. (US Patent 5010219).

Please Note. All pictures are from Geekhack members unless otherwise noted.

[top]"Bigfoot"

US Patent 4642433

This is the most common type of ALPS keyboard switch, and most times when people are talking about ALPS switches, they are referring to these. It was designed to be mounted on a flat steel plate. These switches have 3.5mm travel and a switch life of 20 million operations.

The term Bigfoot refers not to the switch itself but to the shape of keyboards such as the Dell AT-101. It is not an ALPS term.
This type of switch was marketed as ALPS CM switch by US PC and keyboard manufacturers. The part number in the ALPS catalog began with SKCM for tactile and click and SKCL for linear. Hereafter Bigfoot will be used to refer this type of switch for convenience.

Bigfoot switches come in two versions. Complicated and Simplified. Originally the ALPS switch mechanism was quite complicated internally, consisting of many parts. The design was later simplified and subsequently copied by manufacturers other than ALPS.

Complicated



Simplified




[top]Complicated ALPS

Complicated ALPS can be clicky and tactile, non- clicky and tactile, or linear (no bump when pressing down). Although generally regarded as "smoother" than Simplified ALPS there is a wide range of disagreement on this. In addition, ALPS did not appear to publish force diagrams like Cherry Corporation so most ALPS "feel" reviews are highly subjective. For example some people think Orange ALPS are smoother than Black ALPS, others feel no difference at all.

Although not an official manufacturers force diagram the one below seems accurate overall for most ALPS. The black line shows an actuation force of 70g fairly early in the keystroke, and a bit of an uneven curve as the switch continues it's travel. White Clicky Complicated ALPS are felt to be smoother. Blue Clicky Complicated ALPS are reported to be lighter.



[top]Complicated ALPS - Tactile, Clicky

NOTE: In parentheses are reported keyboards that the switch has been found in. Before purchasing a ALPS keyboard be sure to do the re?search. Many ALPS keyboards have the same part number but different switches were used through their lifetime. For example the Wang 724 Terminal keyboard may have Black, Orange OR Pink ALPS. Even having a seller take a picture of the switch is not definitive. For example the a white key slider may indicate a Complicated Clicky ALPS or a Complicated Rubber Dampened ALPS or a Simplified ALPS. The only way you will know for sure is to take apart the switch.

For example the outside of this case makes this look like a standard Dell AT101W Black ALPS - Complicated NonClicky but tactile switches?

it is actuallyType 1 Simplifieds (Fukkas)



ALPS Electronics left the keyboard and keyboard switch business in the 1990's. Some people prefer to call the newer one "FAKES" but I find the whole Fake versus Real designation to not really help in identifying the switch or more importantly how it feels.


White: click (Northgate Omnikey 101, Focus FK-2000 Plus, Focus FK-2001 without Windows keys, Focus FK-3000, Acer 6011, Chicony KB-5161 AT/XT Switchable)

Focus FK-2001 without Windows keys

Click Leaf



Blue: click (some Northgate Omnikey Ultra and 102, PC-8801mkⅡ)


Picture Source

Deep Yellow (like a NYC Taxi): clicky (Some early model Apple IIc models)


The Click leaf is slightly different than the White Complicated Clicky ALPS. Link to post describing differences.


[top]Complicated ALPS - Tactile, NonClicky

Black: tactile (Dell AT-101 new logo, Dell AT-101W 0227KN, Dell AT-102/W, some Wang 724 terminal keyboards)

Dell AT-101W


Cream (some White): tactile with rubber damper (Apple Extended Keyboard II M3501 - Made In Mexico and Ireland. Made in Japan use Mitsumi switches, SGI Granite PN 9500900, 9500829)

SGI Granite Switch Opened Up

SGI Granite Rubber Dampened Slider

Qwerter's Clinic Article on dampening action: link.


Orange: tactile (early Apple Keyboard M0116/M0115/GS II keyboard, some Wang 724 Terminal keyboards)

Picture Source

Pink: tactile (later Apple Keyboard M0116/M0115 , Dell AT-101 old logo, some Wang 724 Terminal keyboards)


[top]Complicated ALPS - Linear (no bump in feel)


Green: linear (Zenith ZKB-2, IBM 5556 keyboards) No Tactile Leaf, Upper Case does not have slot for Tactile Leaf. In this pic you can see a smaller version of this switch with non-typical sliders.

Picture Source

Grey: linear, stronger spring for space bar (Zenith ZKB-2)


Grey: linear, two position key for Caps Lock (Apple Extended Keyboard II)



Light Yellow: linear (Zenith ZKB-2, IBM Multistation keyboards)



[top]Simplified ALPS


Simplified ALPS are felt by some to be stiffer, louder, and not as smooth, with reports of inconsistencies in feeling across the keyboard. Some Simplified ALPS have the ALPS logo on the switch casing. The only way to tell if they are fake/simplified or not is to take the switch apart.

This article covers the different types of simplified ALPS in detail:
http://sandy55.fc2web.com/keyboard/alps_sw2.html
English translation (images are not showing in translated page for some reason)

NOTE: In parentheses are reported keyboards that the switch has been found in. Before purchasing a ALPS keyboard be sure to do the research. Many ALPS keyboards have the same part number but different switches were used through their lifetime. For example the Wang 724 Terminal keyboard may have Black, Orange OR Pink ALPS. Even having a seller take a picture of the switch is not definitive. For example the a white key slider may indicate a Complicated Clicky ALPS or a Complicated Rubber Dampened ALPS or a Simplified ALPS. The only way you will know for sure is to take apart the switch.

Most new keyboard products use these switches simply because the original complicated ALPS switch is no longer available. ALPS Electronics left the keyboard and keyboard switch business in the 1990's.

Blue: click (Focus FK-2001 with Windows keys)
Cream: click (Keypot Technology KPT-84)
White: click (Diatec Filco ZERO, switches marketed as XM; Macally MK96)
Grey: tactile (Strong Man SMK-85, switches thought to be manufactured by Strong Man, known as "ALPS-compatible" (Source: DSI))
Black: tactile
Yellow: linear (DSI Big Font Keyboard)



Examples of simplified ALPS by type

Type I nicknamed "Fukka" Generally regarded as less balky than XMs, activation force around 65g (although the spec says 70g +/- 25g)
Filco ZERO (new version) FKN87Z/EB clicky
ABS M1 nonclicky
Matias Tactile Pro 2.0, 3.0
Solidtek 6600 clicky (Source)
Avant Stellar and Prime




Note: The Fukkas are interesting in that unlike most ALPS switches they appear to publish their specifications (ALPS I believe did too in their paper catalog but I haven't seen any scans online). Source.
Quote:
Maximum contact rating 12 VDC, 100mA
Operation travel 3.5mm + .05mm (0.138 in.)
Type of contact Mechanical
Mechanical Key depression force 70 grams +/- 25 grams
Operation temp -20° C to 60° C (-4° F to 140° F)
Contact resistance 1 Ohm maximum
Storage temp -30°C to 70°C (-22°F to 158°F)
Contact bounce 5 ms maximum
Type II nicknamed "XM". Activation force around 70g.

Siig Minitouch and variants: Ortek MCK-89S, Filco DFK-81E2 - all clicky. NOTE - the current Siig Minitouch Plus is a rubber dome. Look for Model number 1903 and Model number 1948. Even then Model Number 1903 is sometimes a Monterey Switch
. Safest thing, as always with ALPS, is to ask for the seller to pull a key and take a picture
Filco ZERO (old version) FKN87Z/EB-Y
Keypot Technology KPT-84
Macally MK96 (newer models)
DSI Big Font (Yellow linears)

Note the 4 tabs in the corners of the bottom housing. These are visible even without pulling the switch apart.

Note the two slots in the upper housing.



Type III
These have a wide click leaf instead of the small copper style leaf. Instead of two slots in the upper housing it has one slot for the switching assembly. There appears to be a single electrical contact point instead of two thin fingers as on the Type II. Perhaps made by "Strongman", another switch manufacturer of ALPS compatibles.

Focus FK-2001 with Windows keys
SMK 85



Pictures from Sandy55

Type IV
The Simplified Type 4 is like a hybrid of Type 1 and Type 2. It has a wide leaf like a Type 1 but has a switch similar to a Type 2.

On the left is a Type 4, on the right is a Type 2 (XM).


pics courtesy of Sandy55

Macally MK96
Matias Tactile Pro 1.0

NOTE: The Matias Tactile Pro 1.0 has switches stamped ALPS. Link to more pics. The ALPS stamp generally indicates a Complicated Switch ...




but not always.

[top]Low Profile ALPS


There are two types of low profile switch, both designed to be PCB mounted. The earlier type is known as "ALPS Linear" on Qwerters Clinic site. Later type is available in two variations: linear and click action. In ALPS' catalog 1994 edition, these are listed as SKFR/linear and SKFS/click. Features of SKFR/SKFS switches include 10.3mm height with 3.5mm travel, with built-in jumper lead.

This is an example of a low profile ALPS from a ALPS ADB Touchpad:




Earlier linear
Toshiba T5200
IBM 5556 keyboard P/N 5962851

Newer type
SKFS/clicky - Apple Adjustable
http://www7.ocn.ne.jp/~hisao/image/adjustable.htm
http://sandy55.fc2web.com/keyboard/a...djustable.html2"]"Leaf spring"[/H]


[top]Leaf spring


US Patent http://patft.uspto.gov/netacgi/nph-P...number=3899648

This switch was developed under request of IBM Japan and is available only in IBM Japan's products. This switch can be mounted onto PCB directly (older type) and on face plate (newer type). You can see their differences here:
http://sandy55.fc2web.com/keyboard/alps_leaf_sw.html

IBM P70/P75 keyboard ( these are PS/2 but actually made by IBM Japan )
IBM 5576-001 ; To use on Win2000 and later, registry modification is needed.
IBM 5576-002 ; same as above

[top]Older Variations



In addition to the above three types, there are many switches developed by ALPS and these variations are considered predecessors to Bigfoot and low profile switch in ALPS development. You can see these old ALPS switches here: http://www7.ocn.ne.jp/~hisao/jiku.htm

[top]Switches that LOOK like ALPS

Manufacturers OTHER than ALPS sometimes used sliders that can use ALPS keys and therefore have similar looking sliders.

[top]Montereys

Although keys are compatible with ALPS the switch internals are quite different.


Internal parts of the Monterey showing the difference.


[top]Omrons


Blue: click
Yellow: click (pictures and description here at Sandy55's webpage)

White: linear

There are also rubber domes that use a ALPS compatible key stem.

As always, when in doubt with ALPS you have to open the switch to tell 100% what they are.

[top]FAQs



Q. How do I take a key off an ALPS keyboard?

http://geekhack.org/showwiki.php?title=Island:7018

Q. How to open up an ALPS switch?

see video here, using standard "2 screwdriver" method: http://geekhack.org/showwiki.php?title=Island:7121

Do NOT pry too aggressively or you will break the switch bottoms. The idea is to use thin screwdrivers, insert straight down, and pinch the two screwdrivers together and pull, not pry.

Additional info and alternate/faster methods:
http://geekhack.org/showpost.php?p=111922&postcount=11


Q. How do I reassemble it afterwards?

See video here: http://geekhack.org/showwiki.php?title=Island:7121

Be cautious here. You can bend the tactile leaf so make sure you note the orientation of the click leaf.


A spot of vaseline or silicon grease will help "stick" the spring inside the slider and keep it from falling out, which is the main difficulty. Or use a magnet held above the slider.
http://geekhack.org/showwiki.php?tit...light=vaseline (scroll down a bit).


Q. How can I tell an XM switch from a Fukka/Type-I without opening up the switch?

If you remove the key, you can tell between these two switch types without having to further open up the switch guts. You'll need a flashlight to peer at the left-right mounting tabs. See pics linked below. The left-right mounting tabs will be slightly different. The XM's tabs are "ridges" and the fukka's tabs are "flat".
You can see that difference here: http://geekhack.org/showpost.php?p=109390&postcount=1
If you do open up the guts (and as an alternate photo shoot), you'll see this difference: http://geekhack.org/showpost.php?p=116887&postcount=93

[top]Mods


Q. How do I turn my black alps into a poor man's white alps?

Mod to get your black alps to click somewhat.

Q. How do I install dampened sliders into a fukka or other alps board to silence the click sound a bit?

This actual mod being done, example 1.
This actual mod being done, example 2.
See here for lots of additional details: http://geekhack.org/showpost.php?p=174311&postcount=68

Q. Which ALPS boards/switches are a good source for Rubber Dampened sliders?

Apple Extended Keyboard II (the serial number, usually located underneath the bar code, MUST begin with the letter A) or SGI keyboards (part no 9500900) are commonly available on Ebay.

Q. Help, my alps fukka switch seems to be stuck after I modded it!

Common problem. See this post or the thread its in.


Attached Images
File Type: jpg FLA_5346.jpg (266.5 KB, 4264 views)
File Type: jpg FLA_7029.jpg (161.5 KB, 4338 views)
File Type: jpg FLA_7300.jpg (115.9 KB, 4357 views)
File Type: jpg FLA_7291.jpg (213.4 KB, 4194 views)
File Type: jpg apple2c3.jpg (177.3 KB, 3970 views)
File Type: gif alps force charts from webwit.gif (7.8 KB, 2728 views)

Contributors: Chloe, ripster, wellington1869, ch_123
Created by Chloe, 07 January 2009 at 22:21
Last edited by ripster, 2 Weeks Ago at 20:21
Last comment by ripster on 17 November 2010 at 18:40
127 Comments, 15,089 Views

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