Audio digitizer and analyzer
Abstract
The audio digitizer and analyzer is a hardware and software interface for the IBM PC/XT and compatibles. Any voltage varying signal, not only audio, can be sampled and stored in memory. The stored signal may then be analyzed, processed, and replayed through a speaker output.
The software allows for a detailed examination of the waveform through a graphic representation of the digitised signal. There is a built-in facility for magnifying the display and panning along the time domain of the signal. In addition, there are routines for clipping the signal or removing a specified DC offset. For audio applications, the signal can be recorded and run at different speeds. It is even possible to play at reverse speed.
The heart of the hardware interface is a 12-bit Analog to Digital Converter (AD 574A), which has a maximum sampling rate of 25 KHz, and an 8-bit Digital to Analog Converter (Am 6081), which has a settling time of 200 ns. With an appropriate software, the audio digitizer and analyzer may be used as a 25 KHz storage oscilloscope and a programmable function generator.