5576 Keyboard Series

Brief Introduction (K/B for Multistation, 5576 series)
Characteristic Features
Useful links about 5576 K/B
Localized Curved sculpture
Keyboard Connectors
Compatibility issue


Content created by Sandy. Edited by Major Tom. Most of the information regarding key mechanisms and history of IBM keyboards is based on the following sites - Kenjin (maintained by "IT") and Qwerters Clinic (maintained by Mr. Tanaka).

Brief Introduction

Multistation Keyboards

Before talking about 5576 keyboards, I'd like to introduce keyboard for Multistation 5550, computers sold by IBM Japan before MCA PS/55 series.

5556 keyboard is known as associated keyboard for Multistation series. 5556 somehow looked like keyboard for "The PC" (and PC/XT), but the key mechanism used for 5556 was different from that of The PC which used tactile Buckling spring technology. IBM Japan ordered Alps Electric Co. Ltd. new key switch and Alps made their unique "Leaf Spring" and "mechanical contact" switch. Though the Alps switch used for 5556 and alternate keyboards for Multistation series didn't provide clicking noise, the key mechanism was actually a kind of so-called "Mechanical Key". I have not yet touched the keyboard actually so I can't say how the keyboard feel like. The keyboards use new scancode sets (81h, 82h, 8Ah) to support the additional keys (which limits its compatibility).

Here you can see photo images of 5556 and 4773313 (the site is maintained by Mr. IT) and also you can compare how they differ from IBM "The PC" Keyboard and alternatives.

5576 Keyboards for the PS/55 Line

US IBM introduced their great 101 keys Enhanced keyboard with Buckling spring/Membrane contacts mechanism along with PS/2 in 1987. But IBM Japan didn't use IBM's own products but again used Alps key switch "with tactile sound" for their new PC series PS/55, Japanese localized PS/2. Thus keyboard 5576-001 and 002 introduced to the market.

Key layout of 5576-001 is very different from that of Model M. Roughly speaking it looks like 1390876. It has 24 function keys and 10 enhanced keys and was essentially designed to be used with PS/55s as a terminal machines of mainframes (of course those could be used as usual PC systems). 5576-002 has 106 keys (5 keys are added in order to provide Japanese environment) and more looks like Model M layout. Major difference of its layout is that 002 does not have left "Alt" key as like as 001. Later on when IBM Japan tended to consumer market with their DOS/V technology, they made new keyboard, 5576-A01, which was based on 002 but the key layout was rearranged and was followed to Model M to keep operative compatibility. For the new keyboard, IBM Japan ordered Brother Industries. Ltd. to make "Buckling spring key" under cross-license to meet with Japanese users' taste.

As described above, PS/55 keyboards are bit different from PS/2 world. The Model M is really a great keyboard and there are so many M-maniacs in Japan too, but at least for me both 5576-002 and 5576-A01 are the second to None. I like 5576-002 and A01.

Characteristic Features of 5576 Keyboards

Type # of Keys Mechanism Notes
5576-001 124 Leaf spring Alps switch, PS/55 layout
5576-002 106 Leaf spring Alps switch, PS/55 layout
5576-003 99 Buckling spring Brother switch, PS/55 Layout
5576-A01 106 Buckling spring Brother Switch, OADG1) DOS/V layout
5576-C01 98 Buckling spring Ditto, with Trackpoint II
5576-B01 106 Rubber dome OADG DOS/V layout
And more...
1) OADG - Open Architecture Developers' Group (a consortium leaded by IBM Japan to distribute IBM Japan's new technology regarding Japanese (double bytes characters) handling on DOS without any help of special hardware but just 2MB of RAM and 386SX CPU and higher with some added device drivers to PC DOS (or MS DOS).

Except key switch mechanism and the layout of the keys, 5576 series are very similar to model M.

  • Both use Mechanical spring (5576-001/002 use Leaf spring though)
  • "tactile" feedback
  • Curved sculpture design were applied
  • Removable key caps are used
  • Keyboard cable is detachable from a keyboard unit
  • Mechanical Spring and Clicking Sound

    I'm not a technical writer and I don't know much about key mechanism. So I'd like to reference some nice pages covering keyboard mechanisms. These pages are mostly written in Japanese but you can still observe the photos):

    • Alps switch (leaf spring with mechanical contacts) used for 5576-001 and 002 (archive)
    • Brother switch (buckling spring with membrane contacts) (archive)
    • Curved sculpture (archive). Explains the difference between earlier and latter 002.

    Localized Curved Sculpture

    Model M
    As you know, it is Model M, familiar to you PS/2 lovers.

    From the bottom around space bar to the top around function keys, key tops keep curved shape. Arrangement of function keys is very unique.

    From space bar to upper numeric keys are in curved sculpture layout. Key tops of function keys in 2 rows are parallel to surface of keyboard base.
    5576-A01 (and 002/003)
    Same as 001. Height of key tops of function keys from a surface of desk when keyboard are tilted up using legs.
    (Model M: ~6.0 cm, 5576: ~5.5 cm)
    For a man with big hands and long fingers, M would be better.

    Distinctive Difference (shape of the space bar)

    Model M 5576-001 5576-A01

    All of the most lower keys of Model M keyboard (space bar, Alt, Ctrl and numeric keys) are keeping same shapes and key tops are in same curves. While front edge of space key, Ctrl and Alt keys (and other associated Japanese specific keys around space bar) of 5576 are slightly cut off. 5576-001 (picture in middle) shows the difference of the shape.
    Front two keys seeing the picture (two keys at most left facing to the actual keyboard) are added enhanced keys and the position of 3rd key is equal to Ctrl on M keyboard. Height of the edge of those keys give smooth touches especially to both thumb fingers.

    And here's one more arrangement made by IBM Japan.

    Could you notice the fact that the middle key (same position of left Ctrl of Model M) is slightly shorter than the neighboring right key which is marked as Caps Lock (it's 001 keyboard)? The Ctrl key at the right side is in same height. These two keys are usually pressed with little fingers, and (at least for Japanese) this modification makes us easier to type those keys.

    Removable Key Caps


    Dimensions of key tops and caps are different from the Model M so it's not possible to interchange key caps between the 5576 and Model M.

    Keyboard Connectors

    Top view, left - PS/55, right - Model M Bottom view, left - PS/55, right - Model M

    Connector Pinout

    Outlines by John Szybowsky (see his mod page).

    Model M pinouts can be found HERE.

    Compatibility Issue (for Japanese readers only)

    There are compatibility issue for 5576-001/002/003 regarding their S/N and EC level to use with some of PS/55s. Please read here.

    OS support (001/002/003):

    • Windows ME doesn't support the 001/002/003 keyboards.
    • Windows 2000/XP does have keyboard DLL file for the 001/002/003 but you can't select these keyboard using device manager. You have to either modify the keyboard or manually select the DLL file by modifying Windows registry. More information can be found HERE (archived, JP).

    5576-001 (5576 Keyboard-1 P/N 94X1220)

    • Alps leaf-spring key switches with mechanical contacts
    • Audible and tactile feedback (it actually has a speaker at the bottom)
    • 124-key Japanese 001 layout
    • Removable key caps
    • Detachable keyboard cable
    5576 Keyboard-1 (P/N 94X1220). Another photo HERE.

    Thin but huge keyboard this one is. It has 24 function keys and 10 enhanced keys. Key layout looks like that of Emulator 122. Enhanced keys were basically for IBM Japan's proprietary word Processing software "DOS Bunsho Program" which had been sold since Multistation 5550 series. PS/55s were sometimes used as terminal emulators at some big companies along with Multistation series. So the key layout was not so ridiculous at that time, I suppose.

    Alps Key switches gives really good response. Requires lesser pressing force than Model M. but gives firm and sure typing response. Not so loose as Model M, gives tight clicking sound (reverberation of metal spring is tight and firm comparing to Model M). Disadvantage of this keyboard is it's unique key layout. Win95/98 support this keyboard in native but neither Win 2000 nor XP provide keyboard file officially (though both of them have keyboard DLL for this keyboard and it is possible to use it rewriting window's registry data)

    Enhanced keys (alt) Cross-layout cursor keys (alt)
    Double-row function keys
    Bottom view (there's a speaker behind the grill)
    Keyboard label

    5576-002 (5576 Keyboard-2 P/N 94X1110)

    • Alps leaf-spring key switches with mechanical contacts
    • Audible and tactile feedback (it actually has a speaker at the bottom)
    • 106-key Japanese 002 layout
    • Removable key caps
    • Detachable keyboard cable
    5576 Keyboard-2 (P/N 94X1110). Another photo HERE.

    Also uses Alps Key switch with mechanical contacts. Touching response is basically same with 001 keyboard. It doesn't have added 12 function keys and 10 enhanced keys seen in 001. Key Layout is the nearly same with latter A01 model and thus the layout is supposed to be origin for that of A01. Main difference is that 002 dose not have Alt Key at left side of space bar, it has only one Alt key at the right hand side.

    Alternative of this keyboard is labeled as 55760N2 with P/N 07G3331.

    Kanji key below Z/X Speaker behind a grill
    Speaker volume adjustment

    5576-003 (5576 Keyboard-3 P/N 66X1121)

    • Brother buckling spring key system
    • Membrane contacts
    • Tactile feedback
    • 89-key Japanese A01 Layout
    • Removable key caps
    • Detachable keyboard cable
    5576 Keyboard-3 (P/N 65X1121)

    Key layout is same with 5576-002 (Keyboard-2). As you can see this model has no numeric keys. Key switch mechanism used for this model is not, unlike 002, Alps made but Buckling spring mechanism made by Brother Industry Co. Ltd which is also used in 5576-A01.

    Speaker Keyboard Label

    5576-A01 (P/N 79F0167)

    • Brother buckling spring key system
    • Membrane contacts
    • Tactile feedback
    • 106-key Japanese A01 layout
    • Removable key caps
    • Detachable keyboard cable
    5576-A01 Keyboard (P/N 79F0167)

    My favorite one. Have no appropriate words to describe how good it is. Requires much pressing force than the 002 keyboard and repercussion may be harder than 002. But I like it.

    Please go HERE (archived original) for the mechanism of this keyboard. The site is maintained by Mr. Tanaka. you can observe how the key spring works in moving photo images.

    Inner view

    5576-C01 (With a TrackPoint-II, kind of SpaceSaver)

    • IBM buckling spring key system
    • Membrane contacts
    • Tactile feedback
    • 89-key Japanese A01 layout
    • Permanently attached cable

    No picture available. Please check this site for pictures of the C01 keyboard.

    This one was most likely made by IBM US for IBM Japan. The original model of this keyboard might be Mode l M13 Trackpoint II (92G7461). Or Eudora Pro UNI04G6 made by Unicomp is more likely to be its origin if IBM (or Lexmark) had once sold such a keyboard. Outlook is almost same with each other except UNI04G6 does not have a rotating bar used as a leg to keep the keyboard vertically when it is not in use. I do not know whether IBM Japan designed 5576-C01 and ordered US IBM to make it or US IBM had already had that kind of model and just arranged key layout to meet with Japanese market.

    This keyboard was introduced to the market as associated keyboard of earlier models of PS/55E 5538 and 5537. As I wrote in 5538 section, there are two types of this model, one is with with single cable to be connected to K/B port of 5537/5538 which works for TrackPoint II and the other is with "Y cable" separated to K/B connector and mouse connector. The former is P/N 66G8363 and the latter is P/N 66G8362. See the 5538 section too.

    Now I don't have C01. I'm so stupid that I disposed my C01 which had bad film cable which caused keyboard error repeatedly. I should have kept it for repairing purpose.

    Key touch response is... not so good. It might be derived from Model M and actually it gives tactile feedbacks but it is not "M". Design is good, product concept is also good, TrackPoint II on a standard full-key layout may save space for mouse operation. Buckling spring technology should be good but... could it be better? It gives you just noisy tactile sounds. Do not expect C01 for model M's quality. You'll be disappointed, I swear it. But I do want to have a 5576-C01 in good working condition as an associated keyboard for my 5538. So far it is better than cheap rubber dome spring keyboards such as 5576-B01 and others.

    Later Models

    There are few more members of the 5576 keyboard family, that came after the A01 model and were sold mainly with the Aptiva or new IBM PC series. These keyboards use rubber dome spring mechanism and membrane contacts. These are not my choice.


    Some people says this one belongs to mechanical keyboards but as far as I can see, it uses rubber dome spring and membrane contacts. Actually it is different from today's usual cheapo K/B and it gives relatively firm typing but so it was a starter of IBM's cheap K/B (and the End of the High quality Desktop keyboards).


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