The keyboard can be operated with thumbs when the keys are facing the user. If the keypad is facing down, its layout must be mirrored and then it is operated by six fingers as usual.

Keys are physically connected together so that it is possible to turn on either of the two swiches or both. For example, the red key in the middle (B-E) can be pressed with one finger in all thee alternative ways, i.e. B, E of SHIFT. It is also simple enough to press all other combinations with thumbs except A+E+C and D+B+F where index fingers come to help.

A prototype of this IR transmitter was built in summer 2003 (only the upwards option for thumbs plus the mouse controls) and it was regarded as a very practical application. It uses the PIC microcontroller software described in gkos.net (Remote 2: GKOS + Joystick) and is still working with the original 3 volt battery!

S. Tiainen, 10 Feb 2010