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© 1999-2025 Jürgen Müller
juergen@e-basteln.de
Here’s a preview of how the Enigma touch is used. Please see the Quick Reference card and the User Manual for more details.
Basic operation of the Enigma touch is as close as possible to the real machine. When you turn it on, the Enigma touch remembers its most recent machine settings and is ready to encrypt right away: Set your rotor starting positions and start typing and reading ciphertext off the lamps. Here’s an overview of the control elements:
Use the rotor sliders to configure your Enigma: Select the model to be simulated, rotor complement and ring settings, and replica settings like brightness and audio volume.
Civilian and military Enigma models with three and four rotors can be simulated – including machines with and without plugboard, as well as ‘Zählwerk’ machines with cogwheel mechanism.
The military Enigma variants I, M3 and M4 are equipped with a plugboard. In the original, it is arranged vertically in front of the control panel, in the Enigma touch behind it for better handling. Letters can be connected in pairs on the plugboard. This has the effect of swapping them, once before the encoding path enters the rotors and again after it exits and continues to the lamp field.
A physical plugboard is always active for the military Enigma types I, M3 and M4. Make and change connections at any time, as you would on the original machine. The plugboard is also used to set up the field-rewirable reflector D (UKW-D).
The driving mechanism that moves the rotors of the classic Enigma is not reversible: The user can manually turn a rotor back to its previous position, e.g. to correct a typing mistake. But if that rotor had “pulled along” its left neighbor during its prior rotation, the left rotor is not automatically rotated back along with it. Unless the user has observed the left rotor’s movement and turns it back by hand as well, an incorrect rotor position is created and the entire subsequent encryption process is invalid.
As early as 1928, an alternative mechanism was developed in which the rotors were firmly coupled by a gearbox. With a small plug-in crank, the user could turn back the complete rotor set step by step to correct mistakes. A four-digit mechanical counter, which counted the encrypted letters and was also turned back, helped with orientation. Machines of this type are hence known as “counter Enigma” or “Zählwerk Enigma”.
The Enigma touch simulates multiple variants of the Enigma G, a counter machine originally built for civilian applications but also used by the German secret service (Abwehr) and the military of various nations. The character counter and the crank for manual adjustments are supported, of course!
When simulating a ‘Zählwerk’ machine (Enigma G series), the 4-digit character counter and the crank to adjust rotor positions are replicated. Use the rightmost slider to ‘turn the crank’.
Several Enigma variants, both for civilian and military use, used a special reflector “Dora” (“Umkehrwalze Dora” or UKW-D for short), which could be wired by the user. In the Enigma touch, the UKW-D can be used in the Enigma models KD, M3 and M4.
The UKW-D could be opened to reconnect the letters in pairs, using short internal cables. The manual wiring of the UKW-D was time-consuming; therefore it was not rewired daily but e.g. weekly. On the Enigma touch this reflector is also wired by hand, via the plugboard.
It requires a lot of attention from the operator to read the ciphertext from the lamp field and write it down, while reading and typing in the plaintext in parallel. In military use, the Enigma was often operated by two-man teams: one operator to enter the plaintext, one to read and write down the ciphertext.
To increase convenience and avoid mistakes, the “Schreibmax” was offered as an optional add-on: A strip printer that was connected to the lamp field with many parallel wires and automatically typed out the displayed letters. The Enigma touch offers the convenience of the Schreibmax by logging its output via the USB port.
The USB port can act as a serial device, replicating the functionality of the historical ‘Schreibmax’ accessory.
The Enigma touch comes prepared for a rechargeable Lithium-polymer battery. While it can also operate directly from an external 5V power supply, we highly recommend adding a battery. It complements the handy format of the replica – and after all, the original Enigmas were battery-powered too!
The User Manual has details on the battery type and installation, and the Files & Links page gives some hopefully up-to-date links to suppliers.
An optional Lithium polymer battery lets you operate the Enigma touch ‘in the field’, like the original.