| Trilobite 1.4 User Guide | © Darwin Arts L.L.C., 2016

# Patch Basics

This page gives a basic overview of patch properties and terminology, mostly through a simple example.

Topics on this page include:

Simple Feed-forward Patch
Simple Feed-back Patch

## Simple Feed-forward Patch

By way of an introduction to Trilobite Patches, consider the very simple patch simple_osc.da_patch included with the Trilobite installation:

Aside from the rather drab sound it produces, this patch shows the following properties of patches:

  Orientation Signal flow is from right to left (feedback exceptions to this will be discussed in a later section) |
  I/O Ports Modules, represented by blocks, have ports for input (on the right) and output (on the left). In this example detail, the Module is an Oscillator whose input port controls the oscillation frequency, and output port is the generated periodic signal. |
  Connections Outputs are routed to inputs with visible connections, represented by lines |
  Port Scalars Every module input port has a scalar value which may or may not be applied to the input signal depending on the module (see individual Modules Pages to see whether a particular module applies this scalar). If the Port Scalar value is 1.0, it is not displayed. In this example, the Port Scalar value is 2.0. |
  Parameter Mappings Every module input port may optionally have a Mod Synth Parameter mapped to it. With this mapping, the input signal may be scaled with within the range [0, 1] depending on the parameter value. This parameter scalar works in series with the Port Scalar above, depending on the module. In this example, Parameter 0 has been mapped to the oscillator input port. |

## Simple Feed-back Patch

Now consider a modified version of the “simple_osc” patch which is slightly more interesting to listen to and shows a few more advanced features:

  Fan Out Multiple connections may be fanned-out from a single Module Output Port. In contrast, only one connection may be attached to a Module Input Port.
  Feedback A Module Output Port may be connected to any Module Input Port, regardless of their relative signal flow positions in the Patch. A Module Output may even feedback into an input port of the same Module, although this is not pictured here.