mSD Retrofit Decoders The Latest Technology for (Almost) Every Locomotive Decoders for retrofit installation in existing locomotives have been available since the beginning of the digital era in the Eighties [...] just on/off, but also bright/dark, fast/slow, loud/soft... The decoder can be used as a locomotive decoder with 4 or as a function decoder with 8 enhanced outputs. Technical Tip: All functions can also [...] possibilities. Fact 7: Compatibility The new generation of decoders is compatible with all Märklin digital formats and the DCC system. The decoders can be operated immediately with the 6020, 6021, Mobile...