# PatchDemo features and background

PatchDemo is a program that runs on the 3DO development system. It lets you experiment with DSP instruments in a fast and interactive way. Use this program to listen to and prototype complicated DSP instrument configurations for later use in a program.

The PatchDemo program has the following features:

- Runs native on 3DO development systems.
- Reads a text file describing the patch; no C programming is required.
- Has a graphical user interface that provides interactive control of patch parameters.
- Can play any standard DSP instrument.

## Background

The 3DO Digital Signal Processor (DSP) is a powerful software synthesis engine. In order to make use of that power, the audio folio provides an extremely flexible modular synthesis model and a variety of modules called DSP instruments. However, writing a program to connect several DSP instruments is not a trivial task and doesn't provide a simple method to experiment with different configurations, settings, and so on. Because of this, there is a temptation to only do simple things, such as play back samples.

PatchDemo solves this problem by providing an environment in which the existing DSP instruments can be connected in complicated arrangements without the programming overhead. You can describe a patch (a list of DSP instruments and connections between them) in a text file using a simple command set; PatchDemo deals with the operating system. PatchDemo then plays the patch and lets you adjust the instruments knob settings with the control pad.

Because PatchDemo is so easy to use, it provides a fast way to experiment with the various DSP instruments so you can get on with the job of designing sounds. Once you have a patch file that you like, it can be used as a template for writing C code.

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