Hello, Daniel - thanks for the quick reply!

Just after I sent the previous post it occurred to me that the DOS batch file IF format (IF...THEN without any ELSE) is sufficient - a string of those should be capable of handling multiple conditions. It should be OK if the itinerary file can be edited to achieve this sort of command without needing CATrain itself to be able to generate the code. Some words of caution in the documentation might help avoid non-programmers making a complete mess of the logic!

I'm curious about the "Special Function" provision in the "Define Train" dialog box, and how to make use of it. What sort of switching could be activated this way? It would be excellent to have some way of switching lights (battery powered?) or smoke, but I have no idea how this could be controlled in the CAtrain environment. Is it possible to add control signals on top of the PWM voltage that powers the motor, possibly to command a specifically designed function decoder? I assume conventional DCC decoders could not be driven with s PWM 12 volt DC supply.

The cheapest solution for powering a CATrain- driven layout (5 or 6 volts for lights, 12 volts for trains, several amps for several trains) seems possibly to be a PC power supply. These typically produce quite "stiff" 5 and 12 volt DC outputs. I have an old (and dead) Compaq supply on my desk here, and it claims to produce +12 volts at 14 amps (trains), +5 volts at 25 amps (Grain-of-wheat bulbs) and + 3.3 volts at 18 amps (LEDs) as well as -5 and -12 volts at much smaller currents.

I think you should be able to buy a brand-new one for 20 - 30 Euros. Can you think of any reasons why that wouldn't work?

Best wishes!