说明：  数字电子琴的功能 电子琴的每个音阶均对应一个特定频率的信号，通过调用数字信号发生器产生一系列指定的频率的声音，从而达到虚拟的电子琴的功能，界面中包含A、B、…、O共 15 个琴键，鼠标按下时即发声，松开时发声停止。 同时能够产生正弦波、方波、三角波等常见的波形的数字信号，并且提供了图形界面用于选择波形、频率、幅值与相位。能够根据用户指定的波形和参数产生相应的数字信号，然后将数字信号写入声卡的缓冲区，最后由声卡播放出相应的声音。
(Digital electronic keyboard electronic keyboard features both for each scale corresponds to a specific frequency signal, digital signal generator by calling the specified frequency range of voice, so as to achieve the functions of a virtual keyboard interface includes A, B, ..., O A total of 15 keys, the mouse is pressed the sound, let go when the sound stops. At the same time can produce sine, square, triangle and other common digital signal waveform, and provides a graphical interface used to select the waveform, frequency, amplitude and phase. To the user specified waveforms and parameters of a corresponding digital signal, and then write the sound card digital signal buffer, and finally by the sound card plays the corresponding sound.)