基于声卡DSP技术和Visual C＋＋编程技术，提出了一种基于声卡的虚拟信号发生器设计方案.能产生正弦波和方波等四种常用波形，并可调节波形的幅值和频率。-Sound card based DSP technology and Visual C++ programming techniques, a virtual sound card based Signal Generator design. Can produce sine and square wave waveforms of fou