Squeezebox

Virtual device configuration in sim.xml:

    [...]
      <device dsid="16" busid="16" type="example.slim_player">
        <parameter name="port">9090</parameter>
        <parameter name="host">localhost</parameter>
        <parameter name="playermac">00:04:20:1e:2f:ca</parameter>
      </device>
      [...]
      <group id="4">
        <device busid="16" />
      </group>
      [...]

You need to create a config xml file in your data/config.d directory. You can name it slim.xml and put the following lines into it:

<?xml version="1.0" encoding="utf-8"?>
<properties version="1">
  <property name="config">
    <property name="subsystems/DSSim/js-devices">
     <property name="slim_player">
       <property name="script-file[0]" type="string">
         <value>../jslib/dsid.js</value>
       </property>
       <property name="script-file[1]" type="string">
         <value>../examples/plugins/js/slimplayer.js</value>
       </property>
       <property name="id" type="string">
         <value>example.slim_player</value>
       </property>
    </property>
   </property>

This makes the dSS aware that there is a simulated device called example.slim_player. Note that relative paths in this file are relative to the working-directory of the dSS.