I explained how to use the Enigma machine to Patricia Neal in excruciating detail. Feel free to read that here. But it basically boils down to this:
Enigma I (or M3)
Rotor Order (Walzenlage): 3 Roman numerals I-V, with no Roman numeral repeated.
Rotor Setting (Ringstellung): 3 numbers 1-26 or 3 letters A-Z.
Starting Position (Grundstellung or Kengruppen): 3 numbers 1-26 or 3 letters A-Z.
Plugboard Setting (Steckerverbindugen or Steckerbrett): Up to 13 groups of 2 letters, with no letter repeated.
Letters and numbers are interchangeable for the Rotor Setting and Starting Position:
The Atlas Pursuit Enigma Simulator
For your Enigma-deciphering needs, this is the Enigma simulator I created. Truth be told, I didn’t create it from scratch — I just adapted it from the Universal Enigma freeware simulator below created by Daniel Palloks (who I don’t know). My version is easier for novices, English speakers, and mobile users who are reading The Atlas Pursuit. Not every Enigma simulator out there functions correctly, and I know this one works. The web design may be circa-2009 (appropriate for The Atlas Pursuit), but it’s free, and it should work on any computer or mobile device.
I have used a lot of other Enigma simulators that are available on the internet. Here are some thoughts on my favorites. Each has advantages and disadvantages, and each has its own quirks, which I’ll detail. Cryptography experts or people who want the added challenge can ignore this page entirely and figure it out by themselves.
This program replicates the look, sound, and feel of an Enigma machine better than any other simulator I’ve tried. It may not be the simplest to use for deciphering (though it will absolutely work), but it is well worth the download just to get a feel for an actual Enigma machine.
Advantages: Realistic, free
Disadvantages: This is a program that you download to your computer, so it will not work on a tablet or smartphone. It takes some clicking around for a while to learn how to change all the settings.
Mininigma: Enigma Machine Simulator
This is an app for the iPhone or iPad. It is nicely designed and fully functional, and is definitely the most enjoyable simulator I’ve used on a smartphone. It does a surprisingly good job of replicating the feel of using an Enigma machine. It takes a little while to learn how to use all the features, but it is fairly user-friendly.
Advantages: Designed for the iPhone.
Disadvantages: Can only be used on iPhone or iPad. Costs $1.99.
Navy M3/M4 Enigma Machine Emulator
This is a bare-bones but extremely user-friendly simulator. It makes no attempt to replicate the look of an Enigma machine, but it is probably the easiest simulator I’ve used for actually deciphering messages.
Advantages: Intuitive design, free, well-labeled, and in English.
Disadvantages: This website is easy to view on a computer or tablet, but a smartphone screen requires a bite of awkward resizing and scrolling. It’s certainly usable on a smartphone, but it’s definitely not designed for one.
Quirks: Under “Input Method,” clicking “Block of text” allows you to cut and paste text for deciphering.
This simulator can replicate the function of pretty much any Enigma machine ever built. This means, though, that there are a lot of variables on the screen, not all of which are useful for every Enigma machine. It does not attempt to look like an Enigma machine, though it vaguely suggests the layout of the Enigma rotors. The labeling of the buttons and the design are a bit confusing. It is certainly usable, but the learning curve is somewhat steep.
Advantages: Fully-loaded, free, made for computer or tablet but usable on a smartphone with a little scrolling and resizing.
Disadvantages: A bit hard to use and confusingly labeled.
Quirks: Press the button labeled “Rings>>” to set the Rotor Setting (Ringstellung). Press the button labeled “Show plugboard” to access the Steckerbrett, and make sure to click “Activate” after inputting the plugboard setting.