Decoder-equipped locomotives are the third and last piece of the DCC puzzle. In essence, the Commander (or other command station) communicates with the decoder installed in a locomotive, which allows it to control the various locomotive functions like speed, headlights and ditchlights.
 
In addition to decoder-equipped locomotives like the new Atlas Master DCC HO GP38 Locomotive, Atlas offers a patent-pending HO scale Dual-Mode Decoder which allows you to easily switch your locomotive from true analog to digital mode and back again. This is done by simply removing the jumper plug and replacing it in different holes. This allows you to run your decoder-equipped locomotives on your friend's analog layout without experiencing the typical speed differential common with other decoders that are designed to work in both modes. This new multi-function decoder can be easily installed into almost all Atlas locomotives produced over the last 15 years, as well as most other locomotives with a motor-mounted light board. Each decoder comes with the headlights set to Function 0, so you can get started right out of the box. Programming of Function 1 is also available, for advanced users.