Way, way back in 1997, I first discovered the internet. Not long after that, I discovered the now sadly defunct CroTrainz forums, and this great MS-DOS based train simulator called Mechanik.
Unfortunately, the passage of time means that many of the routes created for this simulator have vanished off the face of the internet.

Those I have copies of, I’ve rehosted here, as well as this guide on getting it running on your more modern computer:

First off, you need to acquire a copy of the program-
http://myweb.tiscali.co.uk/theleesfamily/mechanik.zip (This version has French text in the menus)
Now, extract the file you’ve just downloaded into a directory, and make a note of this- I reccomend using a short path with no spaces.

Additional routes may be found on the Mechanik Routes page.

Finally, to get it running, you need to get yourself a copy of DOSBox-
http://dosbox.sourceforge.net/

Note: This should be version 0.74 or above for Mechanik to run correctly.
DOSBox runs a copy of MS-DOS in a ‘virtual machine’, keeping it separate from your Windows installation.
The first thing to do is to install DOSBox, and launch it from the icon it’ll place in your Start Menu.
Next, press CTRL+F12 until the CPU cycles figure displayed in the title of the DOSBox window is at 12,000- This gives Mechanik enough virtual CPU power to run correctly- If you see ‘Runtime Error 105’ when attempting to launch or generate a route, then your CPU cycles are not high enough.

We now need to mount the directory where we extracted Mechanik with DOSBox- If you extracted Mechanik into C:\Games\Mechanik\ then you’ll need this command-

Switch to the C:\ drive in DOSBox with this command-

Load the Mechanik route generator by typing this command-

From there, follow the instructions to generate a route, or load one of the presets from the top menu. When it’s finished, it’ll load Mechanik. You need the first menu option (Démarrer) to start driving.

Additional routes should be extracted into their own folder below the C:\Games\Mechanik folder. From there, there should be an either an .exe file or a .bat file (For example DMU Sim.exe)- Launch this with DOSBox, using double-quotes to enclose the name if there is a space, and you should be good to go.
All the additional routes I currently have are on the Mechanik Routes page. If you have any of the ‘missing’ ones, please get in touch as I’d hate for them to vanish off the face of the internet.