About computer control
Computer control isn't an "all or nothing" affair. You can choose to have a computer involved at lots of different levels. This section provides some ideas about the art of the possible.
At a low level, you can use a PC to maintain a roster of locomotives and to keep records. For example, you may choose to keep records of decoder installation & CV programming.
As a next stage, the PC can be connected to the DCC control system. Decoder programming can be done through the PC. This allows you to specify the required settings in a more meaningful way, then download them to the decoder in one go by the computer. There are several programs that allow this: DecoderPro is free, and is part of the "JMRI" suite; TrainProgrammer is a commercial program that is part of the "Railroad&Co" suite.
You can use a PC to configure, understand and debug the DCC system. There are various programs that will help with making settings for the DCC command station, and various accessory devices. JMRIprovides tools for this. Digitrax users should look at Stefan Trachsler's excellent "LocoNet Checker" program. This configures the command station and several accessories. It also provides a way to monitor point positions and train sensor states.
You can use a PC to display a diagram of your railway. This can show point positions and indicate track sensors being occupied by trans. You can also set point positions, either individually or in routes. You can use an "on screen" throttle to control a train, allowing a level of operational control. The "PanelPro" program that is part of the free JMRI suite does this. The Traincontroller program that is part of the "Railroad & Co" commercial suite allows this.
Finally you can use the PC to automate operations on the railway. This might include driving a train from one location to another, or stopping a train in a station. "PanelPro" allows you to write scripts that can achieve this. Traincontroller includes automated train movements, in various ways, as a standard capability.