BTC 5100

This article requires additional photographic illustration — need photos of the other variants

BTC 5100

FCC ID	E5X5R5BTC-5100 E5X5R5BTC-5100C
Manufacturer	BTC
Features	Embedded numeric keypad
Layouts	80/81-key compact ANSI-derived
Keyswitches	BTC foam and foil (tactile) BTC dome with slider (PCB/membrane)
Interface	AT/PS/2
Dimensions	297 × 152 × 30 mm (5100C)
Weight	0.7 kg (5100C)

BTC 5100 is a series of compact keyboards from BTC.

Description

The keyboard is 14.5 units 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" />

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:

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 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

• 
  Top
• 
  Rear
• 
  Sliders with buckling rubber sleeves
• 
  Slider and sleeve assembly
• 
  Sliders with foil layers
• 
  Slider detail
• 
  Top of PCB with capacitive pads
• 
  Rear of PCB, and controller daughterboard

Big-ass Enter version

• 
  Front
• 
  Rear

Documentation

• 5100C Mini Keyboard User's Manual

External links

• geekhack — BTC-5100c: A True HHKB Alternative (In-Depth Review and Teardown)

References

<references> <ref name="IBT-5100C">IBT Technologies Inc. — BTC 5100 Mini Keyboard, 80/81 Keys, PS/2</ref> <ref name="alps.tw-5100">KBtalKing — ◇◇海綿鋁箔軸靜電容量式BTC-5100簡介◇◇</ref> </references>