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Template icon--Rethink.png This article requires restructuring — how can all these be APC-H412? Especially H410E!
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NEC APC-H412 front view.JPG
FCC ID B7ZAPCH412[Citation needed]
Branding NEC
Manufacturer NEC
Layouts ANSI, ISO
Keyswitches NEC ovals
Interface PS/2, PC/AT
Dimensions 481 × 214 × 41 mm (APC-H4120)
Weight 1585 g (?)
1730 g (APC-H4120)

APC-H412 here confusingly refers to a number of full-size NEC keyboards whose model numbers begin "APC-H41", followed by additional characters.


Examples to date have been found to use NEC blue oval switches and double-shot keycaps. The layout is ISO or ANSI, with one modification: there are no spaces between the control and alt keys.

Weights are attached to each side of the mounting plate.

NEC blue oval switches actuate before the click/tactile point. As a result, you can type without actually causing any of the switches to click. This keyboard is known to resonate a "ping"; in theory it is possible that the frequency of the ping is at the resonant frequency of the springs. The springs may be somewhat loose in the key's resting position. Thus, bottoming out on a key, or releasing it quickly, sends an impulse through the board that elicits the impulse response of a spring: vibration at its natural frequency. With multiple springs responding at different amplitudes, the whole board "sings".

Removing keycaps

It is really easy to destroy a switch by removing its cap the wrong way. The issue at hand is that the plastic plate at the top of the switch which holds everything together is extremely thin. If you pull straight up, and the key is stuck on in any way (easily true for a dirty switch), the force required to free the cap from the slider will be greater than the force required to break the top plate, and everything will fall apart.

Here's the recommended method:

  1. Grab both sides of the key with a Topre style key cap puller. The key cap puller should be vertical, perpendicular to the keyboard.
  2. Rotate the key cap puller to the right about the centreline of the key cap. The left edge of the key cap will rise and the right edge of the key cap will either stay in place or drop.

Adapting to USB

Users have reported[1] that this keyboard is incompatible with the common "Blue Cube" and Belkin converters, but that it does work with with the "straight-through" cable-type PS/2-to-USB converter made by IOGear.



Unspecified version; unknown date.


ANSI version; appears to be from ca. 1989. The legends are an unusually pale shade of grey.


German ISO 102-key version; unknown date.

External links


  1. Geekhack — NEC Keyboard APC-H412 Retrieved 2015-11-20.