codebooks.zip contains the “plain text” of those code books in the collection for which such text was available. Note that these texts are generated with the help of optical character recognition (OCR) and are not transcribed without error.
The filename of each codebook matches its
identifier on this site. For example, the identifier
ciphersecretlett00larr matches the 1884 code book Cipher
and Secret Letter and Telegraph Code, a text for which the full text is
available on the Internet Archive. Within codebooks.zip the file with
this text has a filename that begins with “ciphersecretlett00larr”
Those interested in using computational methods and machine reading to analyze this collection of texts may find the following software and websites helpful:
Keywords and bigrams ordered by weighted frequency.