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 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 scan code used with these keyboards ( 5556 and other alternatives ) are not based on AT specification 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.

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 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 
 

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

  Alps mechanical switch (  Leaf spring with mechanical contacts ) used for 5576-001 and 002 
        http://park16.wakwak.com/~ex4/kb/tech_alps_5576001.htm

  Brother switch ( buckling spring  with membrane contacts)
        http://park16.wakwak.com/~ex4/kb/tech_bucklingspring.htm

  Curved sculpture
       http://nextire.hp.infoseek.co.jp/pc/5576-002.html
 

 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.
5576-001
	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.	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

	dimension of key tops and caps are different from model M so it's impossible to use the caps between  5576 and model M.
5576-A01

K/B plug

Upper  R; PS/55    L; Model M	Bottom  ( from pin )  R; PS/55    L; 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.
 
 

Alps made Leaf-Spring Key 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 

Enhanced keys	Cross-layout cursor keys

label

SP unit is actually placed inside the SP grill.

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

Alps made Leaf Spring Key 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

Kanji key below Z/X	SP unit inside the grill

sliding Vol. bar for adjusting SP level

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

Brother made Buckling Spring key system

Membrane contacts

tactile feedback

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 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.

	Upper;   Label  Left;  SP unit

5576-A01  ( P/N 79F0167 )

Brother made Buckling Spring key system

Membrane contacts

tactile feedback

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.  Want to see more pictures about A01 ?  Click here and select 5576-A01 ( IE is recommended for this site. )

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

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

IBM Buckling spring key system

Membrane contacts

tactile feedback

89Key  Japanese A01 Layout

cabke is dirrectly connected , not detachable.

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.  Please see  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, 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.
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. 
 

There are few more keyboard numbered as 5576 mad 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 . 

5576-B01
Some people says this one is included to mechanical K/B but as far as I can see, this one 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 far it was a starter of IBM's cheap K/B ( and the End of the High quality Desktop keyboard ).

5576-B05