Editing BTC 53 series

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{{infobox dkeyboard
| image name   = BTC5339Front.jpg
| pn           = 
| fcc          = E5X5R5BTC-5339R-0
| branding     = 
| manufacturer = [[BTC]]
| switch       = [[BTC foam and foil]]
| layouts      = 
| features     =
| interface    = [[XT keyboard interface|XT]]/[[AT keyboard interface|AT]]
| weight       = 
| years        = 
| price        = 
}}

'''BTC 53 series''' is a series of keyboards from [[BTC]] with [[BTC foam and foil]] switches. This term (styled as "B T C - 5 3 series") is included on the label of some 53-series keyboards.

53 series encompasses significant variation. There are several case styles, and the sliders can either be supported by a moulded plastic plate (as with [[BTC dome with slider]] keyboards), or in plate-mounted inserts as with [[Realforce]] keyboards. Both the linear (sub-keycap coil spring) and tactile (with a [[buckling rubber sleeve]]). All variants have BTC's 1.25-[[unit]] escape key.

The plastic plate under the keycaps has been found in both beige and black, and the sliders can be found in various colours, including white, cyan, yellow and pink.

There is a "MACRO" key in the lower left-hand corner of many 53 series keyboards, of unknown function.

Many (though not all) variations are confirmed Auto-sense capable between XT / AT protocols. Meaning, it's also compatible with modern PCs' with an AT to PS/2 or a AT to USB Adapter, but due to a lack of a Windows Key(s), it may not be ideal to use on Linux and Mac OS without rebinding a different key to serve as one.

==Variants==

;5339
:US ANSI, with [[enter key|big-ass enter]], "MACRO" key, and backslash to the right of right shift
;5349
:ISO
;5369
:US ANSI, without "MACRO" key. FCC ID: E5X5R5BTC-5369

==Examples==

*Unidentified variant (not listed on label), possibly 5339 — white sliders, beige plate<ref name="HaaTa-5339" />
*[[Leading Edge]]–branded 5369, with black plate and cyan sliders<ref name="eBay-5369" />
*5339, with pad-printed legends (depicted below); the "Alt" legends, and the front printed "SysRq" legend are printed in green, with all other text in black; the enter key is notably lighter, with two much lighter springs and two sliders
*[[Packard Bell]] F21 T083I, includes larger bezels, OEM brand on the top left corner and a pencil holder - likely an older model produced shortly after the [[IBM Model M]].

==Gallery==
===5339 (linear)===
<gallery widths="250" heights="187">
File:BTC5339Front.jpg|Front
File:BTC5339PCBandFoilPads.jpg|PCB and foil-covered pads
File:BTC5339SpacebarSwitch.jpg|Space bar switch
File:BTC5339EnterSwitch.jpg|Enter switch
</gallery>

===5339R-0===
<gallery widths="250" heights="187">
File:BTC-5339R Top.jpg              |Front
File:BTC-5339R Top wo keycaps.jpg   |Front without keycaps
File:BTC-5339R Bottom.jpg           |Bottom
File:BTC-5339R Label.jpg            |Label
File:BTC-5339R Keycaps.jpg          |Keycaps
File:BTC-5339R Sliders.jpg          |Sliders
File:BTC-5339R Keycaps top.jpg      |Keycap legends
File:BTC-5339R Keycaps back.jpg     |Double-shot keycaps
File:BTC-5339R Enter key.jpg        |Enter key
File:BTC-5339R PCB.jpg              |PCB
File:BTC-5339R PCB date.jpg         |PCB date
File:BTC-5339R Controller.jpg ‎      |Controller
File:BTC-5339R Slider plate.jpg     |Slider plate
File:BTC-5339R plate w sliders.jpg  |‎Slider plate with sliders
</gallery>

===F21 T083I (Packard Bell OEM)===
<br />
[[File:53F21.jpg|none|thumb|Front]]
[[File:Back.jpg|none|thumb|Back]]
<br />

==Trivia==
On Linux (particularly on Pop!_OS 20.04 LTS) with Xmodmap, pressing the "macro" Key after entering;"xev | awk -F'[ )]+' '/^KeyPress/ { a[NR+2] } NR in a { printf "%-3s %s\n", $5, $8 }'" in the Terminal, the keycode is registers as "120 NoSymbol".


It's easy to accidentality break the small tabs on the space bar holding on to the wire while removing it, likely due to the age of the plastic. If one of them breaks off, it'll only be stabilized opposite to the broken-off tab

==External links==

*A Little Bit of Keyboards — [http://sandy55.fc2web.com/keyboard/btc5339_coil.html btc_5339_coil] (Japanese)
*[http://www.pcwaishe.cn/thread-13859-1-1.html Plate-mounted BTC-5349] (Chinese)
*[https://plus.google.com/photos/107738986731122287303/albums/5747089504008033217/5747090327377361970 Plate mounted BTC-5349]

==References==
<references>
<ref name="HaaTa-5339">Google+ — [http://plus.google.com/photos/113845661925823397356/albums/5725506812514893745 BTC 5339R]</ref>
<ref name="eBay-5369">eBay — [http://www.ebay.com/itm/Leading-Edge-AT-Keyboard-FCCID-E5X5R5BTC-5339R-0-BTC-5369-KOREA/190857615103 Leading Edge AT Keyboard Fccid E5X5R5BTC 5339R 0 BTC 5369 Korea] {{volatile}}</ref>
</references>

[[Category:BTC keyboards]]
[[Category:Vintage keyboards]]
[[Category:Protocol switchable keyboards]]
[[Category:List of all keyboards]]