Virtual Lorenz

Using Virtual Lorenz

The basic controls of Virtual Lorenz are simple. Each of the twelve wheels can be rotated with the cover open or shut - you can open the cover of the Lorenz using the Lock image.
If you have a touch screen, try touching just to the top or bottom of each wheel to turn or alternatively, swipe up or down in the center of each wheel to rotate.
If you have a mouse, hovering over each wheel will show an arrow for each direction, clicking on them will move one position. If your browser/computer supports it, try swiping with the mouse in the center of each wheel to move them.

Changing the actual wheel settings can be done by simply clicking on each visible switch (with the cover open) to toggle between active and inactive.

The basic controls

See the video above for an example of altering the wheel positions and settings.

Input and output

To enter characters, you can either type with the on-screen teleprinter keyboard, enter using a PC keyboard or enter data using the automatic data entry on the page top-right.

A teleprinter keyboard is slightly different from a keyboard we use today in that it can only send 32 seperate characters, not enough for the full alphanumeric entry with punctuation. The method used is called ITA2 (International Telegraph Alphabet No 2) and requires two seperate keys to switch between Letter mode and Figure mod.

The key to switch into Figure mode is marked "Zi" while the Letter shift key is marked "Bu". Switching into Figure mode means any keys pressed after that will be interpreted as the numeric or punctuation signs while anything following a Letter shift will display as standard characters.

Directly below the Lorenz is three sections which show the current input character which is added to the two key letters (one from the Psi wheels and one from the Chi wheels) and then shows the encoded output character. The five dots and crosses below represent the actual impulses for each character, which when written onto punched paper tape would represent a hole for the cross and a lack of hole for the dot.

The top two tapes below the Lorenz are equivalent to the output tapes on the teleprinters. When in use, the Lorenz was mostly set with two teleprinters, one for sending and one to display the received data. The standard model of teleprinter used a long strip of sticky tape rather than a full page of paper (there was no return or line feed) and the message, once received, would be cut up and pasted onto a page ready to be delivered to the recipient. You can use the scissors icon to do this and the data from the tape will be shown on the document in the top right of the screen. To clear each of the tapes, simply click the bin icon at the end of each line.

The tapes marked ITA2 and Send/Recv would not have been visible to the operator (they would never have seen the encrypted data) but are given for your information to show the data that is being transmitted and received.

ITA2 shows the actual full ITA2 codes being sent - in the example below you should be able to see the string "ABCD. 12345." encoded showing the number 5 to represent the Figure shift and the number 8 to show the Letter shift. A 9 is used to show a space character. This formatting is the same as the one used in Bletchley Park to represent these codes.

The final Send/Recv line is showing the actual encrypted data that is what would have been transmitted by wire or radio - this is the data that was being received by Y stations like the one that was at Knockholt in Kent and sent on to Bletchley Park.