Editing BTC 5100

{{TODO photo|more=true|reason=need photos of the other variants}}

{{infobox dkeyboard
| image name   = 
| pn           = 
| fcc          = E5X5R5BTC-5100<br>E5X5R5BTC-5100C
| branding     = 
| manufacturer = [[BTC]]
| switch       = [[BTC foam and foil]] (tactile)<br>[[BTC dome with slider]] (PCB/membrane)
| layouts      = 80/81-key compact [[ANSI]]-derived
| dimensions   = 297 × 152 × 30 mm (5100C)
| weight       = 0.7 kg (5100C)
| features     = Embedded numeric keypad
| interface    = [[AT keyboard interface|AT]]/[[PS/2 interface|PS/2]]
| years        = 
| price        = 
}}

'''BTC 5100''' is a series of compact keyboards from [[BTC]].

==Description==
The keyboard is 14.5 [[unit]]s wide. The top row of keys—including the function keys—are all reduced in size, to approximately 85% of their normal size (fitting 17 keys across the keyboard).

The various key sizes are as follows:

* Space: 5 u
* Fn, Ctrl, Alt: 1.5 u each
* Backspace: 1.5 u
* Enter: 1.75 u
* Right Shift: 1.25 u
* Function row: 0.853 u

Due to the compact size of the keyboard, the [[keyboard controller]] resides on a daughterboard placed underneath the switch PCB.

The date of introduction is not known. The capacitive version depicted below is dated 1992. The version 1.00 manual for the BTC 5100C is dated 17th of February 1997, suggesting that the capacitive version was replaced or complemented by the conductive version in 1997.

==Specifications==
The specifications for the "5100" are given as follows:<ref name="IBT-5100C" />

{| class="wikitable row-headings"
| Dimensions                  || 297 × 151 × 39 mm
|-
| Weight                      || 0.65 kg
|-
| Switch activation mechanism || Conductive rubber
|-
| Travel	              || 3.5±0.5 mm
|-
| Tactile force	              || 55±20 g
|}

The mention of conductive rubber implies that the page is describing the 5100C and not the original 5100.

The 5100C manual gives the following specifications:

{| class="wikitable row-headings"
| Dimensions                  || 297 × 152 × 30 mm
|-
| Weight                      || 0.7 kg
|-
| Travel	              || 3.8±0.2 mm
|-
| Pretravel	              || 0.9±0.2 mm
|-
| Lifetime	              || 10M
|-
| Tactile force	              || 55±8 g
|}

==Variants==
;Capacitive
:Uses tactile [[BTC foam and foil]] switches; FCC ID is E5X5R5BTC-5100<ref name="alps.tw-5100" />
;5100C
:This is the best-known version, with conductive [[BTC dome with slider|domes]] over a PCB. It is perhaps known better as the [[SIIG MiniTouch Plus]]. Found in both beige (AKA ivory) and black.<ref name="IBT-5100C" /> FCC ID is E5X5R5BTC-5100C. There are slight differences between the AT version and the PS/2 version: the AT has looser, well-lubed sliders and a snappier/louder key press. It also may use ever so slightly snappier domes but the difference is very minimal.    In comparison the PS/2 version has tight scratchy sliders and a muted sound, possibly due to a thicker top housing. 
;Membrane rubber dome
:Same sliders as the earlier revisions, but with standard (pressure) membranes{{citation needed}}
;Flytech
:[[Flytech Carry I keyboard]] is a rebadged 5100 with a revised shell that was registered separately with the FCC by Flytech
;Big-ass Enter version
:In September 2021 a BTC 5100 with a layout identical to some Flytech Carry I models appeared on eBay. It featured a big-ass Enter key, an inverted-T arrow cluster, shorter Control and Alt keys and a larger backspace key. The Home, End, Page Up and Page Down keys formed an extra column on the right of the keyboard, rather than being accessed via Function + Arrows as in the more common model. The top of the keyboard was blank, having neither the pencil tray common to regular 5100s, nor the grooves found on Flytech Carry Is. 
==Gallery==
The PCB of this example is dated week 13, 1992.

===Capacitive===
<gallery widths=250 heights=187>
File:BTC 5100 -- top.jpg                 | Top
File:BTC 5100 -- rear.jpg                | Rear
File:BTC 5100 -- sliders and sleeves.jpg | Sliders with [[buckling rubber sleeve]]s
File:BTC 5100 -- slider assembly.jpg     | Slider and sleeve assembly
File:BTC 5100 -- sliders with foil.jpg   | Sliders with foil layers
File:BTC 5100 -- slider detail.jpg       | Slider detail
File:BTC 5100 -- PCB (top).jpg           | Top of PCB with capacitive pads
File:BTC 5100 -- PCB (rear).jpg          | Rear of PCB, and controller daughterboard
</gallery>

===Big-ass Enter version===
<gallery widths=250 heights=187>
File:Big-ass Enter BTC 5100, front view.jpg | Front
File:Big-ass Enter BTC 5100, rear view.jpg | Rear

</gallery>

==Documentation==
*[[:File:BTC 5100C Mini Keyboard User's Manual.pdf|5100C Mini Keyboard User's Manual]]

==External links==
*geekhack — [https://geekhack.org/index.php?topic=84303.0 BTC-5100c: A True HHKB Alternative (In-Depth Review and Teardown)]

==References==
<references>
<ref name="IBT-5100C">IBT Technologies Inc. — [http://www.ibt.ca/v2/items/btc5100/index.html BTC 5100 Mini Keyboard, 80/81 Keys, PS/2]</ref>
<ref name="alps.tw-5100">KBtalKing — [http://kbtalking.cool3c.com/article/6185 ◇◇海綿鋁箔軸靜電容量式BTC-5100簡介◇◇]</ref>
</references>

[[Category:BTC keyboards]]
[[Category:Compact keyboards]]
[[Category:Keyboards with rubber domes]]
[[Category:Keyboards with foam and foil switches]]
[[Category:List of all keyboards]]