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Here you can find product and ordering information for the Bruce Chubb designed Computer/Model Railroad Interface (C/MRI) System. Since first introduced in a 16-part series in Model Railroader the system has gone through numerous updates making it more relevant today than when it was invented. Its full spectrum of applications includes simplified signaling for the smallest of layouts up to supporting a large variety of expanding applications on the largest imaginable railroad empire. Over 3000 system have been installed on layouts around the world. As a tribute noting its continuing success and to insure its compatibility and functionality on infinitum, the C/MRI has been adopted as the CMRInet Protocol by the NMRA as Layout Control Specification LCS-9.10.1 dated December 2014.

The C/MRI is the most renowned totally universal input/output (I/O) system designed to work with every computer and every model railroad to meet every need. The system is easy to apply, robust, economical and completed tested.  The basic concept is to distribute input/output nodes around your layout, whereby each of your railroad devices that you want interfaced, such as wayside signals, occupancy detectors, switch motors, panel switches, pushbuttons, turnout position, and display LEDs simply connect to input or output pins on the nearest node. Up to 128 nodes are possible, and the only connection between nodes is a single four-wire cable that daisy-chains from node to node.

Documentation on the C/RMI and its abundant applications is exceptional. For example, Bruce has published five books on his system and over 30 articles featuring the C/MRI have been published in the model press. The latest publication is a continuing series covering Railroad Signaling beginning in the December 2015 issue of Railroad Model Craftsman.

The C/MRI system is designed for the hobbyist and primarily for the Do-It-Yourself hobbyist with the goals being easy to understand, assemble, test, install, maintain and expand. You can purchase the C/MRI components fully assembled and tested or as complete kits, however, the most cost effective and most popular approach for medium to large applications is to purchase bare circuit boards from JLC Enterprises to which you can add your own components following the instructions provided in Bruce’s documentation.

JLC Provided Circuit Boards

Note: The quoted prices for all circuit boards provided by JLC Enterprises are for the fabricated boards only, that is, without any electronic parts. All circuit boards come unassembled and less components. All holes are drilled and all circuit traces are tin plated for easy soldering. Where double-sided boards are provided, all feed through holes are plated-through. The SMINI, SUSIC, RS485, DIN32, DOUT32 and PGCC boards have solder masking on both sides, silk screen legend on component side and are factory tested against shorts and open circuits.