User Manual |

Contents of this page

- 1. Introduction
  - 1.1 About this manual
  - 1.2 Introduction
  - 1.3 Installation
  - 1.4 Starting the Enigma Simulator

- 2. The File menu
  - 2.1 Simulation
  - 2.2 Save current settings
  - 2.3 Restore default settings

- 3. The View menu
  - 3.1 The Scrambler
  - 3.2 Viewing the wheel wiring
  - 3.3 The Direct message windows

- 4. Setting up the Enigma
  - 4.1 Setting up the software
  - 4.2 Steckers
  - 4.3 Unlock mechanism
  - 4.4 Resetting the Enigma
  - 4.5 Entering text

- 5. Options
  - 5.1 Sound
  - 5.2 Realistic
  - 5.3 Lamp filter
  - 5.4 Lamp box
  - 5.5 Texture & Lighter
  - 5.5 Configuring the software

1. Introduction

1.1 About this manual

In the manual and in the actual simulator itself, I've tried to use the most common Enigma terminology as found in most publications. The problem here is that we have three possible sources:

- German
- UK English
- USA English

E.g. the movable wheels are called Walze in Germany, Wheels in the UK and Rotors in the USA. Whenever possible, I've used the original German expressions, as most of these were used at Bletchley Park during WWII.
It is assumed that the reader is familiar with the RISC OS operating system and the use of the window environment and mouse. The three mouse buttons have been designated as usual: Select, Menu and Adjust. Furthermore some basic knowlegde of the working principle of the Enigma might be useful.

1.2 Introduction

The Enigma is probably one of the best known devices for message encryption and decryption that was used by the Germans during WWII. This program provides a realistic simulation of the various Enigma models that were used both commercially and by the Military Service. The Enigma is an electro-mechanical device that 'translates' any letter from the keyboard into another one by turing on a lamp on the lamp panel. The translation process is carried out by a series of wheels (Walze) that is moved with each key press.

1.3 Installation

Installation of the software is straightforward. Unpack the file esim/zip with a suitable program such as SparkFS. Next drag the !Enigma-icon to the destination of your choice on your harddisc. That's all...

1.4 Starting the Enigma Simulator

The Enigma Simulator is started, just like any other RISC OS application, simply by double clicking its icon on the harddisc. After a few seconds the Enigma-icon will appear on the iconbar and the default simulation will be opened in a large window. The main window covers about half the screen on a 1024 x 768 monitor and is roughly divided into 4 sections:

Example of the M3 Enigma with serial number M2114

The wheel-section

This is the mechanical part of the machine. It consists of 3 of 4 rotating wheels, the Eintrittswalze (ETW) and the Umkehrwalze (UKW). Some models are also equipped with a counter. The mechanics are hidden by a lid throught which we can see the the current setting of the wheels and these settings to the desired positon.

The lamp panel

This section contains the 26 lamps A-Z. A lamp will be lit whenever a key is pressed.

The keyboard

This is the keyboard containing 26 keys A-Z. Note the German layout of this keyboard (QWERTZ...) instead of the more common English layout (QWERTY...). Some keyboards have extra symbols on the keys as well.

The plug board (steckerbrett) if present

To increase the maximum number of permutations of the device, some models are equipped with a plug panel (steckerbrett) that can be used to swap the letters in pairs. E.g. If A is mapped to P, then P is also mapped to A.

2. The File menu

Put the mouse pointer and open the Enigma-menu (click on middle mouse button). Slide off to File and watch the menu as shown here.

2.1 Simulation

The first item in the File-menu is Simulation and allows you to select the Enigma of your choice. Slide off to open the menu and select the required Enigma model. We call this the Enigma Class. Some models have a further submenu that allows a Skin to be selected. This skin only affects the cosmetics of the machine, not the functionality. The reason for this is that for any given model (e.g. M3) different manufacturers were used. Besides the models were modified and changes were applied as time went by.
The part below the dashed line contains the 'virtual' Enigma machines. These machines do not exist but are created for research of the cryptological aspects, or just for fun.

M3, M1332 | M3, M2114 | M4 Naval machine | Air Force machine | G-312 Abwehr

2.2 Save current settings

When the program is first started, the default Simulation is loaded, complete with its default initial settings. When researching the Enigma, you may at some point want to save the current simulation and the settings for that simulation. To do so, select Save current settings from the menu. Alternatively, press F3 on the keyboard. A warning is issued before the settings are actually saved to disc.

2.3 Restore default settings

This is the opposite of the previous item. Whenever you have saved the current settings, but want to revert to the default one, select Restore default settings from the menu. Alternatively press F2 on the keyboard. A warning is issued before the default settings are actually restored.

3. The View menu

Put the mouse pointer and open the Enigma-menu (click on middle mouse button). Slide off to View and watch the menu as shown here.
The first section of this menu is about viewing the wiring of the various wheels, the ETW, the UKW and the Steckerbrett (plug board). This section is explained in more detail below. The next section affects the viewing of the windows of the first section.
Next are the scrambler options (see Scrambler below). The first one, Scrambler, can be clicked to reveal the Scrambler-window. The option Show numbers should be ticked if you want to have a numbered index on the wheels, rather than the alphabet A-Z.
The final section Direct message can be clicked to open two windows, 'Message in' and 'Message out', that can be used to type a plain or encrypted text directly.

3.1 The Scrambler

When entering a character from the keyboard, electric current is fed via the Steckerbrett (if available) to the ETW (Eintrittzwalze). Next it is passed from right to left through each of the 3 or 4 wheels until it reaches the UKW (Umkehrwalze). The current is the 'reflected' and passes the wheels from left to right until it reaches the ETW again. From there it goes via the Steckerbrett to the lamp panel and will activate one of the lamps. In order to study this process in more detail the Scrambler window has been added. Select from the Enigma-menu: {View > Scrambler}.
The window shown on the right will open. You may want to click on the image to view a larger version of it. The red line show the incoming current whenever a key is pressed. The returning current from the UKW is shown in blue.
The alphabet indicators A-Z are given for clarity only. It can be used to study the translation of each individual wheel. You may want to use a numbered index 1-26 instead of the alphabet. If so, select Show numbers from the View-menu.

3.2 Viewing the wheel wiring

Apart from following the current flow through the scrambler above, you may also examine the exact wiring of each wheel as it changes with each key press. From the View-menu any of the wheels, including the ETW and UKW may be selected. E.g. select Wheel 1 from the menu and watch the wiring change as you press a key.
If the option Allow multiple windows is off, only one of the wheels can be viewed at a time. If the option is ticked however, you may select any combination of wheels to be viewed, each in a separate window. Select View all to open all windows aligned side by side.

3.3 The Direct message windows

Typing a message directly on the Enigma keyboard is a rather time consuming activity. Especially when trying to decode a message, you may want to enter text in a more direct way. Select Direct message from the View-menu. Two small windows will be opened and the upper one has the input focus. Type a message directly into this window and see the cyphered message appear in the lower window.
The Direct message windows have their own menu, which can be opened by placing the pointer over one of the message windows and clicking Menu (middle mouse button).

Alternatively, if you have the input text available in a text file, you may drop this file directly in the 'Message in' window.

4. Setting up the Enigma

Before starting to encode or decode messages, the Enigma needs to be setup for a given key. During WWII code books were used to provide a unique key for every day. On a real Enigma this is a mechanical process that involves opening the lid and removing the wheels. The key then gives the choice and order of the wheels (e.g. 325). For every wheel the Ringstellung needs to be set (e.g. AWM). The wheels are then inserted in the machine and the lid is closed. Next the operator needs to set the initial position of each of the wheels, called the Grundstellung (e.g. KNG). For a 4-wheel Enigma, of course, 4 wheel parameters need to be set. On some models the Umkehrwalze can be given a Grundstellung too.
If the machine is equipped with a Steckerbrett, the next thing to do is to setup the cross connections with a set of patch cables. Each cable swaps two letters, increasing the maximum number of encryption possibilities significantly. In the code book the Stecker connections were given as: AE RJ KM. This means that A is steckered to E and E is steckered to A. Also R is steckered to J, etc.

4.1 Setting up the software

In the Enigma Simulator we want to setup the same parameters as in the real thing. To do this Select Edit settings... from the Settings-menu. Alternatively, you may press Ctrl-E from the keyboard. On some Enigmas locks were used to keep the lid of the case closed. These locks are also present in the Enigma-window and you may click the mouse on them as an alternative to using the menu. The following window will open:

In this window, all the basic settings can be entered and altered. The order of the wheels is given in the way they are seen by the operator. The leftmost settings are for the UKW. Whenever more than one UKW is available, it can be selected by clicking the menu icon.
Next are the settings for the wheels (3 or 4). The numbers of the selected wheels are given in roman numbers, just like it is engraved on the actual wheels. Basic settings for all wheels are Walzenlage (wheel order), Ringstellung (ring setting) and Grundstellung (index setting). In the example given here, the UKW fields for Rungstellung and Grundstellung are greyed out. The reason for this is that for the given Enigma model, the position of the UKW is fixed and cannot be changed.

If you want to use the current position of the wheels as the default Grundstellung, click the button marked Use current as Grundstellung. For models with a Steckerbrett we also want to enter the letter pairs to be swapped. Once you've completed the settings, click OK to confirm. The Enigma will now be reset to the given settings and you can start to type a message...

4.2 Steckers

Some models are equipped with a Steckerbrett that will allow more complex permutations that are far more difficult to crack. On those models (M3 and M4) the Steckerbrett (patch panel, or plug board) is visible in the bottom section of the main Enigma window. If no steckers are used, every letter will be mapped to itself (self-steckered). Whenever a patch cable is used, a pair of letters will be swapped. The letter pairs, up to a theoretical maximum of 13, may be entered in two different ways.
4.2.1 Using the 'Edit Settings'-window
Letter pairs can be entered directly from the keyboard using the Edit settings window as described in the previous section. Type the required letter pairs in the 'Steckers' field, separated by a comma or space. When finished, click on OK to confirm. The Enigma will now be reset and the Steckers will become active.

4.2.2 Using the visual Steckerbrett The visual Steckerbrett can be used as a more realistic alternative to the above. Select Steckerbrett... from the Setting menu, or press Ctrl-P, or click in the Steckerboard area in the main Enigma window. The Steckerbrett window will open and you are now able to add, alter or remove a patch cable simply by dragging the mouse. The window title shows how many cables are used and how many cables are available. Additionally, the Steckerbrett has an undo buffer that allows you go back up to 20 steps if you make a mistake. Please note that any changes made to this window will have immediate effect, i.e. there is no need to click an OK button. |

The Steckerbrett window has its own menu that can be opened in the usual way, by clicking Menu over it (middle mouse button). Most of the options will be self-explanatory.
Remove all cables
Use this function, or the keyboard short-cut Ctrl-M, to remove all cables from the Steckerbrett. If you click this option accidently, use the Undo feature to go back one step.

Undo/Redo The Steckerbrett has a full Undo/Redo buffer that allows you to go back up to 20 steps, in case you've made a mistake. The size of the Undo buffer is currently fixed to 20 steps, but can be increased by changing the following line in the !Run-file:

- `Set Enigma$Undo 40`

this will increase the buffer to 40 steps (or any other size that you want).
Cable options
The cables used on a real Enigma are black. In order to improve the display in such a way that you can distinguish each individual cable, you have the option to use red cables, or even fully coloured ones.
If the option Short cables is ticked, you can see which two letters are connected (swapped) simply by following the cable. If you find this distracting, you may deselect the option, in which case the cables are all running down the window and will 'disappear' at the bottom.
The final option allows you to exceed the available number of cables, just in case you want to experiment with this. If you want to run a realistic simulation however, you may want to leave this option unticked.

4.3 Unlock mechanism

This option will be greyed out with most Enigma simulations, except for the G-models. As the Enigma G features a completely different wheel transport mechanism, a lever is used to unlock the wheels prior to changing the initial wheel position. This lever is accessible through a hole in the top of the cover, from the front of the Enigma. The lever can also be locked/unlocked by clicking on it in the main Enigma window. |

4.4 Resetting the Enigma

The Enigma Simulator can be reset to the default settings (as entered in the Edit settings-window), by selecting Reset from the Settings-menu. Alternatively you may press Ctrl-R on the keyboard. You will hear a mechanical sound to indicate the fact that the machine has been reset to the initial position. If the currently selected Enigma model is equipped with a character counter, this counter will also be reset.

4.5 Entering text

Once the above settings are all completed, you may start to encode or decode a message. Entering text can be done in a variety of ways. Clicking the mouse You may use the mouse to click on any of the keys on the graphical keyboard in the Enigma-window. Be sure to keep the mouse depressed until you've seen which lamp is being lit. Whenever you release the mouse, the lamp will be switched off and there is no way back... just like on the real Enigma.
Using the keyboard
Whenever the Enigma-window has the input focus, you may use the keyboard to enter letters. Press the key of your choice (and keep it depressed) until you have seen the 'translation'. Whenever the key is released, the lamp will be switched off and there is no way back... This is exactly how a real Enigma works.
Entering a fast message
Alternatively you may open the Direct message-window from the View-menu and type a message directly into this window. Whenever the Message-window has the input focus, the simulator uses a fast translation and the realistic animations and sound of the Enigma-window are bypassed.
Loading from file
You may also prepare a complete message as a text file and drop this file in the Message in-window. This can be useful when decoding a range of messages that were all encrypted with the same key.

5. Options

The Options-menu, as shown on the right, gives access to a number of options that can be set by the user. The default settings and some other configurable parameters can be set in the Configure-window (see below).

5.1 Sound

The first option controls the sound which is on by default. Whenever a key is pressed, a realistic sound sample is played. The sound was recorded from a real Enigma M4 by Jim Oram in the USA. Whenever the sound is considered to be disturbing, e.g. in a class room, it may be turned off by deselecting this option.

5.2 Realistic

The Enigma Simulator tries to mimic the behaviour of the real Enigma as accurately as possible. Whenever a key is pressed it takes a little while before the encoding is worked out. This is exactly how a real Enigma behaves. Pressing a key involves activating the rotating stepping mechanism of the wheels and occasionally a turnover on the next wheel. First the mechanism is moved into the new position and then the cyphering takes place. A sound is used to illustrate the mechanical process. Moving the wheels manually with the mouse in the Enigma-window has the same behaviour as on a real Enigma. Here too a sound is used to illustrate the movement.
If you don't want this realistic behaviour, you may turn it off by deselecting the option Realistic in the Options-menu. If you do so, the encoding process is much faster and the wheels can be moved in place more quickly. If you want to study the behaviour of the Enigma, you may want to leave this option on however.

5.3 Lamp filter

Some Enigma models were equipped with an optional lamp filter. This is a transparent green filter that can be placed over the lamps on the lamp panel. Locks on the Enigma case were used to keep the filter in place. If available, the option Lamp filter can be used to turn the filter on or off. Alternatively, you may click on the locks in the Enigma-window to do the same. The filter was used to make the encoded letters better readable in bright sunlight. |

Without filter

With filter

5.4 Lamp box

The Swiss K Enigma was equipped with an external lamp box to allow an extra operator to read and write down the ciphered message. Use this option to open/close the extra lamp box. The option is greyed out on models without an external lamp box. Additionally, you may click on one of the 'locks' on the panel to add or remove a green lamp filter. |

Without filter

With filter

5.5 Texture & Lighter

The bottom section of the Options-menu controls the appearance of the Enigma's metal case in the Enigma-window. By default a rather dark metal texture will be used that closely resembles the actual texture of the Enigma. If Texture is deselected, a dark grey colour will be used instead.
Additionally, you way want to tick the option Lighter to make both texture and background colour a little bit lighter. This can be useful if your monitor has a low contrast.

Standard texture

Lighter texture

5.5 Configuring the software

From version 1.00 onwards, support for !Config has been implemented. !Config is a separate application that is available freely from X-Ample Technology or from the RISC OS Enigma pages. Open the iconbar menu and click Choices...

A configuration window will open, showing all user configurable settings of !Enigma. The top of the window shows a number of TABs, each referring to a group of settings. Click the appropriate TAB to view the settings. Make any changes as required and click Save once you are satisfied with your new choices.
About Config
!Config must be 'seen' by the filer before starting !Enigma. The best place to install !Config is in the Boot.Resources directory on your harddisc. Full details can be found in the !Config application.

© Copyright Paul Reuvers. Last changed: Fri,29 Mar 2002.10:00:40