"INSIDE ENIGMA"
** SECOND EDITION **
BOOK UPDATES

http://EnigmaMuseum.com/enigma_book_updates2.htm
( Copyright (c) 2019, Tom Perera and Dan Perera )
The "www.EnigmaMuseum.com - Enigma Museum

INTRODUCTION
This page contains cumulative updates, revisions, and corrections to the information in the SECOND EDITION of the book: "INSIDE ENIGMA" by Tom Perera and Dan Perera; published in 2019. The SECOND EDITION contains almost twice as much information as the first edition and over 150 additional illustrations

Updates for the FIRST EDITION of the book may be found at:
http://EnigmaMuseum.com/enigma_book_updates.htm

Updates for the Enigma Library CD-ROM may be found at:
http://EnigmaMuseum.com/mecdcor.htm


New information about cipher machines is constantly coming to light as historic government archives are declassified and studied by historians. This information as well as corrections and revisions will be added to this page as often as required.

PLEASE HELP !
If you have any corrections, suggestions, additions or can supply photographs and/or additonal information to make future editions of our book and Enigma Library CD-ROM better and more accurate, please email us using the address at the bottom of this page. Thanks.



ADDITIONAL PUBLICATION:
On 27 June, 2009, we published the 4th. edition of the CD-ROM entitled: "The Story of the ENIGMA: History, Technology and Deciphering"
It is the most complete source of information on the Enigma in a single publication. It contains twice the material in the 3rd edition and includes a complete History, Thousands of Photographs, Books, Wiring Diagrams, Enigma Simulator Programs, Videos, Information on the Russian cipher machine FIALKA and many others. Click above for more information.
(Revisions & Corrections for all Enigma CD-ROM editions:)


25 January, 2019: This page was first published on the internet.
The following items have been added in order of receipt. Most recent first.


Page 136 - 25 September, 2019
Correction from Arnold Reinhold:
The number of positions on the three stepping relays should be 25... Not 20.

Page 136.
Correct the end of the second sentence in the second paragraph to read: "...used three 25-position electromechanical stepping switches that stepped around like Enigma rotors every time they received an electrical impulse from the keyboard."

Page 136.
Correct the next-to-last last sentence of the top figure caption on the right side of the page to read "This is a slightly simplified version of the NARA diagram showing the three 25-position, 20 layer stepping relays at the top and the 25 position, 6 layer stepping relay on the left."

Page 136.
Correct the first sentence in the caption of the middle figure in the right column to read: "This block of three 25-position stepping switches came from a Japanese Purple machine.


Page 28: "How the Enigma Machine Works": - 11 September, 2019
Suggested Addition from Ron Gruner - K4RHG:

We have not provided a clear explanation and diagram explaining how the Enigma rotors are rotated.
Here is an explanation and some photographs:

EXPLANATION:

The Enigma rotors are moved by three pusher/levers that are activated by a metal frame whenever a key is pressed.
The rightmost rotor is rotated one step by its pusher/lever every time a key is pressed.

The middle rotor is rotated one step when a notch on the rightmost rotor allows its pusher/lever to drop into its notch so that it is in position to step the middle rotor.
This step can be set to occur at any one of the 26 positions by setting the ring setting of the rotor which sets its notch position.
So, the middle rotor steps once for every 26 steps of the rightmost rotor.

The leftmost rotor is rotated one step when a notch on the middle rotor allows its pusher/lever to drop into its notch so that it is in position to step the leftmost rotor.
This step can be set to occur at any one of the 26 positions by setting the ring setting of the rotor which sets its notch position.
So, the leftmost rotor steps once for every 26 steps of the middle rotor.

Three spring-loaded wheels press against the thumbwheel indentations of the rotors to stabilize them.

PHOTOGRAPHS:
(These photographs show an unrestored Enigma as it is disassembled for the first time.)

Here is a photograph of the metal frame that lies under the keyboard and is pushed down every time a key is pressed.

Here is another photograph showing the metal frame with the keyboard and light panel removed.
Pushing a keyboard key pushes down the front of this frame.
The frame pivots in the middle and causes the three pusher/levers in the back to move upwards.

Here is a photograph that shows the hinge that allows the metal frame to pivot down in front and up in back.

Here is a photograph showing the metal frame completely removed from the Enigma.
The three pusher/levers are visible at the back of the frame.

Here is a photograph showing the three pusher/levers that rotate the rotors when they are moved upwards by the metal frame.

Here is a closer view of the three pusher/levers that rotate the rotors:
Note that the rightmost pusher/lever is half the width of the other two.
This allows it to fit within the narrow space needed to advance the rightmost rotor on every keypress.

The other two (middle and leftmost) pusher/levers are double the width.
They ride on top of the shoulder of the rotor to their right until its notch allows them to drop down to engage and advance their rotor.

Here is a photograph showing the three rubber (in some cases metal) wheels that press against the thumbwheel indentations on a rotor and hold it firmly in place after it has been stepped by its pusher.
The levers that support these wheels do not move up or down.
They simply support the wheels that hold the rotors in position after their pusher/levers have rotated them.

SUMMARY:

Pushing a key pushes down the front of the metal frame.
The frame then pivots causing the rear of the metal frame with the three pusher/levers to rise upwards.
This upward movement causes the rightmost pusher/lever to rotate the rightmost rotor one step.
When the rightmost rotor has stepped to the position of its notch, the pusher/lever to the left drops into its notch and causes the next rotor to the left to rotate one step.
When the middle rotor steps to the position of its notch, the left pusher/lever drops into its notch and causes the next rotor to the left and to rotate one step.
The round rubber (or metal) indexing wheels do not move up or down.
They simply hold the rotors in place after the rotors have been pushed by their pusher/levers.



Page 17 - 7 August, 2019
Correction from Jerry McCarthy:
Right Hand Column: There are two mentions of the number 17,536. These should be 17,576.

Page 90 - 7 August, 2019
Correction from Jerry McCarthy:
References section: "Wladyslaw" should be written as "Władysław" (both letters "l" are the special Polish "ł".

Page 93 - 7 August, 2019
Correction from Jerry McCarthy:
Pronunciation of "Jerzy" - is "YEZH-ih" not "YEH-ih".

Page 96 - 7 August, 2019
Correction from Jerry McCarthy:
In the coin picture: "Rejweski" is incorrect. it should be "Rejewski".

Page 96 - 7 August, 2019
Correction from Jerry McCarthy:
Poznan" is mispelled; it should be "Poznań" with the special Polish "ń".

Page 101 - 7 August, 2019
Correction from Jerry McCarthy:
Three occurrences of "Wetterkurzschlussel"; these should be written as "Wetterkurzschlüssel" with German "ü". ("Schlüssel" is a tricky word which uses "ü" in both the singular and plural.)

Page 111 - 7 August, 2019
Correction from Jerry McCarthy:
"Collossus" is a mispelling; it should be "Colossus"..

Page 131 - 7 August, 2019
Correction from Jerry McCarthy:
I don't think that the Enigma-E is sold by Bletchley Park anymore. On the inventors Paul and Mark's website, http://cryptomuseum.com they no longer list BP as a seller, only a museum in The Netherlands.

Page 86 - 30 July, 2019:
There is a new edition of Dr. Ray Miller's book: THE CRYPTOGRAPHIC MATHEMATICS OF THE ENIGMA that is reprinted in its entirety starting on page 86 in the latest edition of our book.

The new edition of his book is now available for viewing and download on the internet at:
https://www.nsa.gov/Portals/70/documents/about/cryptologic-heritage/historical- figures-publications/publications/wwii/CryptoMathEnigma_Miller.pdf?ver2019-07-31-064622-023


Page 197 - 9 May, 2019:
We inadvertently left out a very fine website by the late Tony Sale. It covers a great deal of Enigma history and the work of the Polish and British Codebreakers as well as the more advanced codebreaking work at Bletchley Park:
Tony Sale's Enigma History Website: http://codesandciphers.org.uk



Please send us any corrections or additions so that we can make this page and future editions of the book as complete as possible.


Professor Emeritus Thomas B. Perera Ph. D. and Dan Perera.

Internet On-Line ENIGMA Museum: http://EnigmaMuseum.com
Internet On-Line Telegraph & Scientific Instrument Museums:
http://w1tp.com


COPYRIGHT NOTICE: (Copyright (c) 2018: Prof. Tom Perera Ph. D. and Dan Perera)
Although all the pictures and text in these internet pages are copyrighted, you may use any of them for your own personal applications including public lectures and demonstrations, publications and websites as long as you mention the www.EnigmaMuseum.com Enigma Museum. If you plan to offer them for sale to the public in any form, you must email us for permission which we will generally grant as long as you mention our museum: http://EnigmaMuseum.com. Our email address is given at the bottom of this page. Some of the material may require contacting other copyright owners for commercial use and we will inform you about this by email. Please also see the disclaimer of warranty.