Editing NTC KB-6251

{{TODO source}}
{{infobox dkeyboard
| image name   = NTC KB-6251EA -- top.jpg
| pn           = 
| fcc          = FMA44HKB6251 (1988)<br>FMA44HKB6252EA<br>fma44hkb6451
| branding     = 
| manufacturer = [[NTC]]
| made in = Thailand, Malaysia
| switch       = [[Alps SKCM Blue]]<br>[[Alps SKCM White]]<br>[[Omron B3G-S series]]<br>[[Cherry MX Blue]]<br>[[Aristotle Cherry MX clone]]<br>[[Mitsumi miniature mechanical]]<br>[[alps.tw Type T5]]<br>[[alps.tw Type OA2]]<br>[[Xiang Min KSB-N]]
| keycaps      = Pad-printed, double-shot ABS
| layouts      = 101/102-key [[Asian 101]]
| features     = 
| interface    = [[XT/AT switchable]]
| weight       = 
| introduced   = 
| price        = 
| precedes     = [[Unikey KWD-601]]
}}

'''KB-6251''' is a widely-sold family of slimline Alps keyboards from [[NTC]] (Nan Tan Computer Company). Current examples found use a bigass [[enter key]] and single-[[unit]] backspace key. The Alps switches are mounted onto a plastic or metal plate, giving this slimline model a very light weight. Variants with amber [[Omron B3G-S series]] switches or [[alps.tw Type T5]] mounted into a metal plate were also made. Keycaps can be double-shot or pad-printed.

The XT/AT switch, located next to one of the flip-out feet, is unconventionally labelled as "80206/8088" instead of "A/X" (per the [[NTC KB-6151]]) or XT/AT.  Newer models may also have "80206/8088" raised lettering on the bottom panel, but no switch.

The version with Windows keys is [[Unikey KWD-601]].

June 6, 2020: Spotted a Zeos keyboard with Hi-Tek Series 725 black switches ("Space Invaders") [https://www.ebay.com/itm/Lot-of-3-Vintage-1980s-Zeos-White-ALPS-Mechanical-Keyboard-5-Pin-As-Is-/202736820290 on ebay.]  RT-101+ model number on bottom case label.

==Variants==
===KB-6251===

*Branded as Champking Computer Co.<ref name="Champking-B3G-S" /> and Champion Computer Co.<ref name="S-6251-Om" />
*Chinese layout, with double-shot English letters and pad-printed Chinese characters
*Amber [[Omron B3G-S series]] switches including space bar, mounted into a metal plate
*FCC ID FMA44HKB6251

===KB-6251/2===

*Listed as "KB-6251/2" on rear label<ref name="gh-1391406" />
*ANSI layout with doubleshot keycaps
*[[Alps SKCM White]]
*FCC ID FMA44HKB6251

===KB-6251/2===

#[[Cherry MX Blue]]<ref>https://geekhack.org/index.php?topic=79814</ref>
#White [[four-tab clone]]s<ref name="ovau1" />

===KB-6251EA===

*[[Alps SKCM Blue]]<ref name="gh-6251EA-blue" /> or [[Alps SKCM White]]

====Plastic plate example====

*Pine [[Alps SKCM White]]
*Found in UK 102-key layout, with no exterior markings of any kind except QC and serial number
*PCB model NTC 71-6071A-505
*The official designation is not known, as the rear label is missing; KB-6251EA is the model written on the PCB, which is often incorrect due to different models sharing a single PCB

<gallery widths="250" heights="187">
File:NTC KB-6251EA Top.jpg                                |NTC KB-6251EA ALPS Pine Top
File:NTC KB-6251EA Label.jpg                              |NTC KB-6251EA ALPS Pine Label
File:KB-6251EA Switch Top.jpg                             |KB-6251EA ALPS Pine Switch Top
File:KB-6251EA Rear.jpg                                   |KB-6251EA ALPS Pine Rear
File:KB-6251EA Close.jpg                                  |KB-6251EA ALPS Pine Close
File:KB-6251EA PCB Marking.jpg                            |KB-6251EA ALPS Pine PCB Marking
</gallery>

===KB-6251EN===

*[[Alps.tw Type OA2]]
*Ultratech Branded
*Plastic Plate
*ANSI layout
*Doubleshot keycaps
*Found on eBay Australia

<gallery widths="250" heights="187">
File:NTC KB-6251EA -- top.jpg                             | Top
File:NTC KB-6251EA -- side.jpg                            | Side
File:NTC KB-6251EA -- bottom.jpg                          | Bottom
File:NTC KB-6251EA -- rear view.jpg                       | Rear
File:NTC KB-6251EA -- identification markings on PCB.jpg  | Identification on PCB
File:NTC KB-6251EA -- pad-printed legends.jpg             | Pad-printed legends
File:NTC KB-6251EA -- white complicated Alps switches.jpg | White complicated Alps switches
File:NTC KB-6251EA -- dismantled switch.jpg               | Dismantled switch
File:NTC KB-6251EA -- switch mount.jpg                    | Switch mount
File:NTC KB-6251EA -- plastic mounting plate.jpg          | Plastic mounting plate
File:NTC KB-6251EA -- plastic plate and circuitry.jpg     | Mounting plate and circuitry
File:NTC KB-6251EA -- XT-AT selector switch.jpg           | XT/AT selector switch
File:NTC KB-6251EA -- XT-AT selector switch on PCB.jpg    | XT/AT selector switch on the PCB
File:NTC KB-6251EA -- cable mouting in case.jpg           | The cable is secured to the case with adhesive
</gallery>

====Metal plate examples====
There are versions with a black-painted steel plate or an unpainted steel plate.  Some of these examples have Zeos branding.<ref name="sandy2" />

*[[Alps SKCM White]]
*US layout

*[[alps.tw Type T5]]
*Zeos branded
*US layout
<gallery widths="250" heights="187">
File:Disassembled_keyswitch_and_keycaps.jpg           | Disassembled keyswitch + keycaps
File:NTC-KB6251EA v6.0.jpg                            | Main board + model name
File:Back Label.jpg                                   | Back label
File:NTC-6251EA missing switch.jpg                    | 8088/80286 "missing switch"
File:Removed keycaps + steel plate.jpg                | Metal mounting plate + grey switches
</gallery>

===KB-6251EM===

*Tactile yellow [[Mitsumi miniature mechanical]]<ref name="6251em_mgur" />
*Dataware-branded
*Uncertain layout

It is possible that the "M" in "EM" stands for "Mitsumi", giving "A" for "Alps" in "EA". Unlike the KB-6151, where "EN" has been seen on an Alps clone version, Alps clone KB-6251 keyboards also use "EA".

===KB-6251LN===

*[[Xiang Min KSB-N]] Green switches
*Asian 101 layout
*FCC ID FMA44HKB6251
<gallery widths="250" heights="187">
File:NTC KB-6251LN_--_top.jpg                      | Top
File:NTC KB-6251LN -- bottom.jpg                   | Bottom
File:NTC KB-6251LN -- bottom label.jpg             | Bottom label
File:NTC KB-6251LN -- top no caps.jpg              | Top no caps
File:NTC KB-6251LN -- top removed.jpg              | Top removed no caps
File:NTC KB-6251LN -- switches and LN sticker.jpg  | Switches and LN sticker
File:NTC KB-6251LN -- back of the pcb.jpg          | Back of the PCB
File:NTC KB-6251LN -- identification on pcb.jpg    | Identification on PCB
</gallery>

===Unspecified suspected KB-6251 variant ("Super Kingsun")===
This variant in the AT-style US "Big Ass Enter" layout is branded for "Super™ Kingsun", evidently in reference to Super Kingsun Ltd<ref name="Digital in China Agreement" />, bearing their logo on a fairly low-quality silver-on-black sticker on the upper left of the top case. It makes no mention of the manufacturer or any model or part number anywhere on the case, and although there is a spot for an FCC ID on the foil sticker, it was either never printed on mine or rubbed off before I got it. There is a separate sticker on the back indicating that it was made in Hong Kong. Based on what little info I can find, it seems likely that this was sold in China, despite the US layout.

*[[Alps SKCM White]] switches, which appear to be unlubricated
*FCC ID missing from sticker on my board
*"Big Ass Enter" AT-style US layout
*Printed keycaps (not doubleshot)
*Has the Intel 8088/80286 labelled XT/AT protocol switch labels moulded into the plastic on the bottom of the case, with a nearby protocol switch to toggle between them

<gallery>
super_kingsun.jpg|top view
super_kingsun_logo.jpg|logo sticker
super_kingsun_label.jpg|label
super_kingsun_switch.jpg|protocol switch and "Made in Hong Kong" sticker
</gallery>

===Unspecified UK KB-6251 variant ("dan")===
This variant is branded for "dan Personal Computers", bearing their blue "dan" logo on the upper right of the top case, and makes no mention of NTC other than indirectly via the FCC ID. According to the sticker, it was "made in Thailand for dan Technology plc (UK)".

*[[Alps SKCM White]] switches, which appear to be unlubricated
*FCC ID FMA44HKB6251 on the sticker
*PCB labelled "71-E103A-103", mounted on an unpainted metal plate
*UK 102-key ISO layout
*Printed keycaps (not doubleshot)
*ISO-style, textless icon modifier key legends except for the Return/Enter key, which has both the "Return" arrow and the text "Enter" above it, approximately centred on the keycap
*Has the Intel 8088/80286 labelled XT/AT protocol switch labels moulded into the plastic on the bottom of the case, despite not actually having a protocol switch (it seems this is likely a slightly later model which exclusively speaks "AT" with scancode set 2)

===KB-6252===

*[[Aristotle Cherry MX clone]] switches<ref name="gh-Aristotle" />
*102-key layout
*FCC ID unknown

===KB-6252CH===

*Spanish 102-key layout
*FCC ID FMA44HKB6251
*Tactile yellow [[Mitsumi miniature mechanical]] switches<ref name="6252CH_imgur" />

===KB-6252EA===

*102-key layout
*FCC ID FMA44HKB6252EA (not in the FCC's records)
*[[Alps SKCM Blue]]<ref name="schlimmfeld" /> and white Alps switches of unknown variety.<ref name="lovestory" />

====Blue Alps version====
<gallery widths="250" heights="167">
File:NTC KB-6252EA keyboard.jpg                           | Top, with aftermarket label
File:NTC KB-6252EA interface selector.jpg                 | Interface selector switch
File:NTC KB-6252EA label.jpg                              | Rear label
File:NTC KB-6252EA switch.jpg                             | [[Alps SKCM Blue]] switch
</gallery>

====White Alps version====
<gallery widths="250" heights="167">
File:KB-6252EA-White-7.jpg                                | Front, aftermarket label
File:KB-6252EA-White-1.jpg                                | Internals, front
File:KB-6252EA-White-2.jpg                                | Internals, back
File:KB-6252EA-White-3.jpg                                | Close up of switches
File:KB-6252EA-White-4.jpg                                | Front, no caps
File:KB-6252EA-White-5.jpg                                | Back panel, resold by Quattro
File:KB-6252EA-White-6.jpg                                | Close up of PCB
</gallery>

===KB-6451EA===

*[https://www.ebay.com/itm/Vintage-Zeos-No-KB-6451EA-Mechanical-Keyboard-101-Keys-Tested- Spotted on ebay]
*101-key layout
*FCC ID FMA44HKB6451
*[[Alps SKCM White]]
*12 function keys on the left of the keyboard.  F11 and F12 are above all the other function keys, next to the ESC key.
*[https://www.ebay.com/itm/ZEOS-NTC-VINTAGE-CLICKY-keyboard-KB-6251EA-8088-Enhanced-101-keys-5150-5160 Zeos-branded version also spotted on ebay.]
*XT/AT switch

===KB-6752EA===

*102-key layout
*FCC ID FMA44HKB6251
*[[Hua-Jie AK series]] green switches.
*Desoldered XT/AT switch

<gallery widths="250" heights="187">
File:NTC 6752-EA -- top.jpg                               | Top
File:NTC 6752-EA -- Hua-Jie AK green switch.jpg           | Cap removed from a [[Hua-Jie AK series]] green switch
File:NTC 6752-EA -- back label.jpg                        | Back label
File:NTC 6752-EA -- top removed.jpg                       | Top removed
File:NTC 6752-EA -- caps removed.jpg                      | PCB and switches with keycaps removed
File:NTC 6752-EA -- PCB back closeup.jpg                  | Identification on PCB
</gallery>

===Unknown (SFON)===
Unknown "KB-6251" with [[SFON Alps clone]] switches (no photos were posted as evidence)<ref name="unknown1" />

===Unknown (Optimus KB-6251)===
Unknown "KB-6251" sold in Poland under [[Optimus SA]] brand<ref name="Optimus6251" />

*[[Aristotle Cherry MX clone]] switches<ref name="gh-Aristotle" />, plastic plate
*[[Big-Ass Enter]] key and a 1 unit backspace
*No XT-AT switch
*FCC ID LIAKB-6251 — this example appears to have been made after this product range was transferred to Unikey (FCC grantee LIA), prior to the model transitioning to the 104/105-key [[Unikey KWD-601]].

<gallery widths="250" heights="167">
File:Optimus 6251 - Top.jpg                               | Top
File:Optimus 6251 - Switch.jpg                            | Cap removed from a [[Aristotle Cherry MX clone]] switch
File:Optimus 6251 - back label.jpg                        | Back label
</gallery>

==References==
<references>
<ref name="Champking-B3G-S">KBTalking — [http://kbtalking.cool3c.com/article/8485 ⊕⊕Champking KB-6251美容換膚清毒素⊕⊕] (Japanese only)</ref>
<ref name="6251em_mgur">{{dead|Imgur — [http://imgur.com/a/cAhRp#R0jBT1M Keyboards]}}</ref>
<ref name="schlimmfeld">schlimmfeld — [http://www.schlimmfeld.de/?m0=0200-PC+keyboards&m1=0100-NTC+KB6252EA NTC KB6252EA] </ref>
<ref name="lovestory">Deskthority — [http://deskthority.net/news-reviews-f4/keyboard-love-story-viii-usps-dell-ntc-kb-6252ea-t4749.html Keyboard Love story VIII - USPS, Dell, NTC KB-6252EA]</ref>
<ref name="gh-1391406">Geekhack — [http://geekhack.org/index.php?topic=48241.0 My $15 Acquisition]</ref>
<ref name="ovau1">Overclockers Australia Forums — [http://forums.overclockers.com.au/showthread.php?t=987628&page=3 Cleaning/Restoring my IBM Model M - Page 3] (page 3)</ref>
<ref name="gh-Aristotle">Geekhack — [http://geekhack.org/index.php?topic=52391.0 UNIKEY KB-6252]</ref>
<ref name="gh-6251EA-blue">Geekhack — [http://geekhack.org/index.php?topic=53276.0 Blue ALPS broke my heart (question about broken keyboard)]</ref>
<ref name="sandy2">Sandy — [http://sandy55.fc2web.com/keyboard/zeos_6251ea.html zeos_6251ea]</ref>
<ref name="S-6251-Om">Sandy — [http://sandy55.fc2web.com/keyboard/leo_6251.html leo_6251ea]</ref>
<ref name="unknown1">外设天下 — [http://www.pcwaishe.cn/thread-314650-1-1.html 光头哥求科普：谁来解读APLS？？]</ref>
<ref name="Optimus6251">utensilia.tk [http://www.utensilia.tk/optimus_kb-6251/ Optimus KB-6251]</ref>
<ref name="6252CH_imgur">Imgur — [https://imgur.com/a/Xrt9Y BTC mecánico (casi ISO-ES winkeyless)]</ref>
<ref name="Digital in China Agreement">NY Times — [https://www.nytimes.com/1993/11/24/business/digital-in-china-agreement.html]</ref>
</references>

[[Category:NTC keyboards]]
[[Category:Keyboards with Alps SKCL/SKCM switches]]
[[Category:Keyboards with Omron switches]]
[[Category:Keyboards with Aristotle switches]]
[[Category:Keyboards with Mitsumi miniature mechanical switches]]
[[Category:Protocol switchable keyboards]]
[[Category:Vintage keyboards]]
[[Category:List of all keyboards]]