Editing DEC LK401

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{{infobox dkeyboard
| image name   = LK501_top.jpg
| pn           = 
| branding     = 
| fcc          = 
| manufacturer = [[Digital Equipment Corporation|DEC]], [[Cherry]], [[Honeywell]]
| switch       = [[Rubber dome]] on membrane.
| layouts      = 108-key [[DEC LK201|LK201]]/VMS layout (aka. DEC ANSI), 73-key Unix layout (aka. DEC Short ANSI)
| interface    = LK401: RS423, 4800 bps; LK501/LK521: SERIAL.bus; LK41x/LK45X: PS/2
| weight       =
| introduced   =
| price        = 
}}

The '''LK401''' and '''LK501''' keyboards are keyboards from [[Digital Equipment]] Corp (DEC) for DEC computers and terminals such as the [http://terminals-wiki.org/wiki/index.php/DEC_VT420 DEC VT420] and the [http://terminals-wiki.org/wiki/index.php/DEC_VT510 DEC VT510].

The '''LK401''' variant uses the same 4800 bps RS423 interface as the [[DEC LK201|LK201]], while the '''LK501''' variant uses SERIAL.bus (a DEC-specific variant of [http://en.wikipedia.org/wiki/ACCESS.bus ACCESS.bus] that uses the same connector and high-level protocol, but different wire order and is powered by +12V instead of +5V typical for ACCESS.bus).

The '''LK450/LK451''' keyboards were terminal emulator boards for the PC, having both DEC LK-style legends, and PC legends. They used a standard PS/2 interface and differed by the key legends used (the 451 featured a "Gold key" and markings for the DEC WPS/ALL-IN-1 word processor layout). 

The later '''LK411''' had the same legends as the LK401, but used a PS/2 connector instead of the traditional DEC terminal interface. These were intended for use with DEC's (later Compaq's and HP's) Alpha workstations, and later DEC terminals which used the PS/2 keyboard interface (the VT5xx series). The '''LK412''' featured WPS legends. The '''LK41R''' was a later revision of the LK411, allegedly differing by European RoHS compliance.

It is a rubber dome keyboard with a curved backplane and sliders integrated into the keycaps.
It has the LK201 layout with the addition of three extra keys - an additional 'Compose' key, and two 'Alternate Function' keys. The keycaps have spherical tops with legends printed in the corners like on the LK201.

There are several variants, in several national layouts and sometimes with specialized function keys that are dyed orange. There were also special layouts for Far Eastern languages (specifically Chinese, Japanese, Korean and Thai)

There are compact versions of the keyboard with model numbers '''LK421''' and '''LK521''', which were considered as more suitable for Unix than the fullsize layout which was largely designed for VMS and DEC's earlier operating systems. These used the traditional DEC terminal interface, and SERIAL.bus interface respectively.

==Gallery==
===LK501===
<gallery widths="250" heights="167">
File:LK501_top.jpg|Top view
File:LK501_bottom.jpg|Bottom view
File:LK501_profile.jpg|Side profile
File:LK501_mounts.jpg|Key mounts
File:LK501_label.jpg|Product label
</gallery>

[[Category:List of all keyboards]]
[[Category:Terminal keyboards]]
[[Category:DEC keyboards]]
[[Category:Vintage keyboards]]
[[Category:Keyboards with rubber domes]]