The old Walthers non-indexing turntable kits uses a 12V DC motor to position the bridge requiring eye balling to align the rails. The motor has a worm that drivers an intermediary shaft which in turn has a worm that drives a 4" gear attached to the shaft connected to the bridge. Newer indexing turntables use a motor in the bridge to turn a gear at the end of the bridge aligned with the ties molded into the pit. A quadrature encoder attached to the motor is used to determine position, along with an opto-coupler in the end of the bridge and pit wall used as a reference point.

In 1985, Bruce Chubb developed the Computer/Model Railroad Interface (C/MRI) to allow computer control of model railroad accessories: signals, occupancy detectors, turnout control and sense. See JLC Enterprises His modules communicate with a computer via an RS-485 serial interface.

As an embedded firmware developer, we invested significant effort developing mechanisms to debug and exercise our code outside of product requirements. Such tools are analogous to meters and oscilloscopes used by hardware engineers.

The Arduino Interactive Development Environment (IDE) includes a Serial Monitor under the Tools tab. The serial monitor (SM) displays text using Serial.print() but also allows text to be sent to the Arduino. Serial.read() will read text sent from the SM one ASCII character at a time.

I recently started operating some new layouts.  I was overwhelmed when the builders started describing the sub-section of the railroad they modeled.  In my cases, the New Haven RR in New Haven and the Denver, Rio Grande & Western between Durango and Antonito.

My small two siding point-to-point layout has little space for car storage. I finally recognized the value of staging and felt I had enough room for a vertical staging yard. I gave it a try using inexpensive materials I had available.

The elevator is made from 1x4" lumber platforms on which track is laid that are attached to vertical 1x2" strips using 4" angle brackets. I believe there is enough space for two tracks on 1x4" lumber.

Retired embedded firmware engineer (EE) from Bell Labs and Qualcomm.  Developed real-time code for data terminals, speakerphones, CDMA phones, echo-cancellers, voice-recognition, optical communication, optical amplifiers, Linux ethernet driver and OFDM multi-band radio control.

Guitar, biking, RC sailplanes and FAA glider license.