JMRI® is...
Setup
JMRI Setup and Installation
JMRI environments...
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By the community of JMRI.org:
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JMRI®: Setup

General Installation

Installation

Full instructions for installing JMRI on different platforms can be found here:

JMRI® requires that Java be installed:

As of JMRI 4.20, JMRI is only fully supported when running on Java release 8 or 11. As of JMRI 4.99.1, JMRI is only fully supported when running on Java release 11 as noted above. Some problems have been encountered while using a Java version beyond Java 11 and support is offered only on a "best effort" basis. Some issues may only be addressable by using a supported version.

Starting the program

Once you have downloaded the JMRI® software and installed it, simply open the program in the usual manner for your operating system. Windows will show an icon on desktop (with default install options selected).

windows desktop icons

Double click the icon for the program to open. In this case we will open DecoderPro®

This dialog will appear briefly as the program is loading:

Start dialog

You should see this or a similar opening screen displayed after the program starts:

Splash screen

If this is the first time you run the program after you installed the software, the Preferences screen will come up automatically to allow you to set up the system for your particular configuration. Also if you change your system configuration, OR if you have your laptop away from the railroad, but you want to play with JMRI there is a simulator mode you may want to try.
[To be continued]

Setting your Preferences

Fixing Problems