A Zoom talk by Ruth Bourne, one of the wartime Women of Bletchley Park (see her Wikipedia biography). Ruth was a serving WREN during the war and one of the team who successfully decoded the messages transmitted from the notorious ENIGMA machines.
Ruth’s PowerPoint slides are here:
https://enfieldover50sforum.org.uk/newsite/wp-content/uploads/2021/01/Bletchley-Park.pptx
or as a .pdf:
https://enfieldover50sforum.org.uk/newsite/wp-content/uploads/2021/01/Bletchley-Park.pdf.