This Atlas Snap-Track layout appears in the Atlas Model Railroad Company's book "Beginner's Guide to HO Model Railroading". It includes a reversing section which can be controlled with a Digitrax AR1. DC Control For DC operation, Atlas specified an Atlas Controller (for the reverse loop), two Atlas Selectors (to control eight track segments) and seven controllers for the railroad's turnouts. DCC Makes Things Simple With DCC, the wiring of this railroad is considerably simpler. Because each locomotive has a unique address, the section insulated gaps and the two Selectors are not necessary. Likewise, the Controller is replaced with the AR1 ...