5576 Keyboard Series

Brief Introduction
 K/B for Multistation
 5576 series

Characteristic Features
Useful links about 5576 K/B
Localized Curved sculpture
K/B Plug & Pin-out
Compatibility issue




I hereby declare that most of contents regarding key mechanism and history of IBM keyboards written in this section are mostly based on ( and refereed  to ) following sites,  " Kenjin " maintained by pseudonym IT ,  "Qwerters Clinic" maintained by Mr. Tanaka .  Also I referred to many useful web sites which will be introduced here and there in the following scripts.     Great thanks to the Editors of those great pages . 

Brief introduction

Keyboard for Multistation 5550
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 clicky 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.   Scan code set used with these keyboards ( 5556 and other alternatives ) are deferent from AT code set so these keyboard can't be used for decent  windows PCs. 

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

Edit; you can see some of multistation keyborad here


5576 series,  for PS/55.
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 feels and audible clicking 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 (  no joke here ).  I like 5576-002 and A01.

Back to top

Characteristic Features of 5576 Keyboards 

5576-001 124 keys   Leaf spring mechanism Alps switch, PS/55 layout
5576-002 106 keys  Leaf spring mechanism Alps switch, PS/55 layout
5576-003 99 keys  Buckling spring mechanism Brother switch, PS/55 Layout
5576-A01 106 Keys  Buckling spring mechanism Brother Switch, OADG *1DOS/V layout
5576-C01 98 keys  Buckling spring mechanism ditto ,  with Trackpoint II
5576-B01 106 keys  Rubber dome mechanism  OADG DOS/V layout
and more......

OADG *1 ;
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  Plate Spring though ) 
  •  "tactile" feedback with clicking sound
  • Curved sculpture design were applied 
  • Removable key caps are used 
  • Keyboard cable is detachable from a keyboard unit

    Edit;  Plate spring switches are introduced as Leaf Spring switches in another famous sites.
             But said switch is described as Low Profile push button switch with audible feedbak and
             the spring is referred as *plate spring* in the paper. 
             To avoid confusion with leaf springs used in other mechanical ALPS switches, I may 
             refer this Low Profile switches used in 5576-001/002 as *Plate Spring Switches* . 

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 quote  some nice pages relating keyboard mechanism though those pages are mostly written in Japanese ( but you can observe key mechanism through photos ).

  Alps mechanical switch (  Plate Spring with mechanical contacts ) used for 5576-001 and 002 

  Brother switch ( buckling spring  with membrane contacts)

  Curved sculpture

Actually this page is explaining difference of earlier 002 and latter 002, but the pictures show curved layout of keys and base plates.

 Or see these pictures ( 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.
  M      ; aprrox 6.0cm
  5576 ; approx 5.5cm 
For a man with big hands and long fingers,  M would be better. 

  Distinctive difference ( shape of the space bar )

Model M.

Most of lower keys of Model M keyboard (  space bar, Alt, Ctrl and numeric keys ) keep 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  shapes. 
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.

Back to top

Removable key caps

dimension of key tops and caps are different from model M These are not compatible among 5576s and Ms.

K/B plug
Upper side    L; PS/55    R; Model M Bottom side  ( from pin )  L; PS/55    R; Model M.

Pin-out of PS/2 connector and K/B Plug

 Original outlines were drawn by John Szybowsky. Click here for original outlines

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 only )
Win ME doesn't support 001/002/003.
Win2000/XP does have keyboard dll file for 001/002/003  but you can't select these keyboard using device manager.  If you can rewrite  keyboard.inf  you can do that.
If not , you have to manually set dll file modifying windows registry. 
Information is found  here.   Take care.

Back to top

5576-001 ( 5576 Keyboard-1   P/N 94X1220 )
  • Alps made Plate-Spring Key Switches with Mechanical contacts
  • Audible and tactile feedback ( it actually has a SP at the bottom )
  • 124Key Japanese 001 layout
  • Removable Key Caps
  • Detachable Keyboard cable 

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   Cross-layout cursor keys 

SP unit is actually placed inside the SP grill.

Back to top

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

  • Alps made Plate  Spring Key Switches with Mechanical contacts.
  • Audible and tactile feedback ( it actually has a SP at the bottom )
  • 106 Key Japanese  002 layout
  • Removable Key Caps
  • Detachable Keyboard cable

Also uses Alps Key switches with mechanical contacts.  Key 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 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 side. 

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

 Kanji key below Z/X  SP unit inside the grill

sliding Volume  bar for adjusting SP level

Back to top

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

  • Brother made Buckling Spring system
  • Membrane contacts
  • tactile feedback with clicking sound
  • 89Key  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 key sections.  Key switch mechanism used for this model is not Alps but Buckling spring switches made by Brother Industry Co. Ltd which is also used in 5576-A01.  Mine feels somehow different from A01.  I may be wrong but I feel 003 is bit lighter than A01.

                        Upper;   Label

 Left;  SP unit


Back to top

5576-A01  ( P/N 79F0167 )

  • Brother made Buckling Spring system
  • Membrane contacts
  • tactile feedback with clicking sound
  • 106Key  Japanese A01 Layout
  • Removable Key Caps
  • Detachable Keyboard cable
My favorite one. Have no appropriate words to describe  how good it is.
Requires much pressing force than 002 keyboard and repercussion may be harder  than 002. 
   But I like it. 

Please visit here 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 

By the way, I misplaced  some key caps after cleaning caps to take pictures....

Back to top

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

  • IBM Buckling spring system
  • Membrane contacts
  • tactile feedback
  • 89Key  Japanese A01 Layout
  • cabke is dirrectly connected , not detachable.
No picture is available.  Please check this site for pictures of C01 keyboard. 
Most possibly this one is  US IBM's products for IBM Japan. Original model of this keyboard might be  Model M13 Trackpoint II (92G7461 ).   Or  Eudora Pro UNI04G6 made by Unicomp.  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 pre-production  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 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.  Please see  5538 section too. 

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, Track-point 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.

There are few more keyboard numbered as 5576 made after A01,  but they are mainly sold with Aptiva or new IBM PC series with which  Rubber Dome spring mechanism and Membrane contacts were applied.  These are not my choice . 

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


 Back to top

PS/55 Index Page