A piezo-electric oscillator has a reduced manufacturing cost using a general purpose piezo-electric vibrator, while coping with miniaturization. An upright piano main action rail also has all whippen mounting holes located on the lower front surface instead of the lower rear surface as is traditional. A bitmask generator generates a bitmask value representative of the data in the data field of each data record and appends to each data record stored in the memory a bitmask data field containing the bitmask value representative of the data in the data field of the corresponding data record. The detector field of view is divided into multiple segments, each capable of independently measuring the intensity of laser light incident thereon as a function of time. The channel filter is comprised of lowpass filters having a band characteristic given to a communication channel, and outputs band-rejected baseband signals i and q by filtering the outputs of the interpolator. The method includes storing first data of the DMA descriptor at an address that is identified by second data of the DMA descriptor.