The invention relates to a method and apparatus in connection with a wristop computer. The MgAu alloy forming the electron injecting electrode may contain not more than 85 atom % of Au. Signer private information is taken out from a first signer private information storage part and set to the variable d. A second interface logic routes the packet to the component of the packet core network, including aggregating other packets of the same type received from other remote nodes, if the packet is received from a femto cell and destined to the packet core network. Thus, the integral-action control of the gain ensures that the band-pass-filtered and demodulated information signal is above a digitization threshold during its pulses and below the digitization threshold during its pulse intervals. In some embodiments, the timing signal associated with each device under test is maintained at an integer multiple of the tester timing signal.