Enigma Instructions.


Click on the screw knob half way down the right hand side of the Enigma machine, just above the lamp panel).

The top opens to show the Enigma wheels.

Release the Enigma wheels by clicking on the release knob top left.

The wheels come out and the wheel box appears containing wheels 1 to 8, ordered from left to right.

Click on wheel 5, then wheel 3 then wheel 4 to place them in the Enigma machine.

Now click on the wheel release knob to close the wheels.
The ring letters appear, 3 letters to each wheel.

Click below the boftom letter or above the top letters until Z Z Z is shown as the middle letter on the wheels.

Now click on the screw socket, middle right on the Enigma machine to put down the top.

Now go down to the plug board (Stecker in German).

There are 26 socket pairs on this panel and the layout is the same as the keyboard layout.

To plug A to D, click on the A pair of sockets, a Stecker plug, "Oa" will appear. Since the wires cannot be shown, the plugs are numbered 0 to 9 and lettered "a" and "b" to indicate the two ends.

Now click on the D pair of sockets and plug "Ob" will appear.
You have now "Steckered" A to D.

Now do the rest of the pairs in a similar manner.

GB KM VT XI YR

If you make a mistake click on the top right hand corner of the plug board and it will be cleared and you can start again.

Now the Enigma machine is in its base setting.

The next thing is to set the wheel positions.

The Bombe stop showed DMQ, so click on either the top or bottom of the finger notches to turn the wheels until the indicator letters DMQ show in the windows above the wheels.

The message and its crib, with wheel start BZR reads:

rstuvwxyzabcdefghijklm
NGYBVZRPNTTHWCFMPECFUM
CKSAKAGNMLNMQKDXQRZATK
Now take the 5th pair of letters, V K. These are used in the menu and Steckers for both of these have been found by the Bombe.
To allow for the difference between the Bombe right hand wheel start of A and the position of this pair, at "v" offset, turn the right wheel to letter L.
hijklmnopqrstuvwxyzabc
NGYBVZRPNTTHWCFMPECFUM
CKSAKAGNMLNMQKDXQRZATK
Now put the mouse pointer on key K, press the left button and lamp V will light, showing correctly that K -> V at this configuration of the Enigma machine.
The preceeding pair, A B, in the message was not used in the message but Steckers for both A and B were deduced so it should encipher correctly.
Turn the right wheel to K and press key A. The lamp B lights which checks this out. Now carry on enciphering along the message. A -> Z fails, lamp H lights, but the Stecker for A is known so Z must be actually Steckered to H.
Go down to the Stecker board and plug Z to H.
Back off the right hand wheel one position and try enciphering A again.
The Z lamp lights this time so another Stecker has been found.
hijklmnopqrstuvwxyzabc
NGYBVZRPNTTHWCFMPECFUM
CKSAKAGNMLNMQKDXQRZATK
Carry on along the message. The next pair that fails is M -> N, it gives Q so since M Stecker is known, N must be Steckered to Q. Do this and carry on. The next pair L -> T fails. It is T that has a known Stecker so go back one position and key T. The O lamp lights and so L must be steckered to O. Do this and carry on.
hijklmnopqrstuvwxyzabc
NGYBVZRPNTTHWCFMPECFUM
CKSAKAGNMLNMQKDXQRZATK
The next pair to fail is K C revealing C Steckered to E. Do this.
Decrypting proceeds until the pair Z C which fails. Since the Steckers of both are known, middle wheel turnover is suspected. Advance the middle wheel by one position, step the right wheel back and now Z -> C so the correct position for the right wheel turnover has been found, but from the numbers along the top it should have been at position "w". So the Ring on the right wheel must be moved to J to bring the turnover to the correct position. Lift the top cover and do it.
Now setting the middle wheel back to M and the right hand wheel to R, enables the whole of the BZR message to be decypted.
rstuvwxyzabcdefghijklm
NGYBVZRPNTTHWCFMPECFUM
CKSAKAGNMLNMQKDXQRZATK
Finally the actual original Enigma middle wheel position was Z but the Bombe gave M so the middle Ring should be M. Similarly the left hand Ring needs to turn to X for a wheel position of B. Do these and check that the message still deciphers.
The German Naval Enigma configuration for the day's messages was thus:
534 . XMJ . AD GB KM VT XI YR ZH NQ OL CE