I was at the Cheltenham Science Festival today (with the girls, never too early to get girls interested in Science!!) and there a stand from GCHQ (UK Government Communications Headquarters which is the centre for Her Majesty’s Government’s Signal Intelligence (SIGINT) activities) and they had a genuine Enigma Code machine on display. It was working and able to encode and decode – just like during the war.
Click on the photos for larger versions.
This unit was made in 1937. This photo shows the overall unit. Note the three code wheels just above the lights that are part of the pre-shared key for the unit.
The next photo shows the front code selectors which used jumper leads in a preset configuration. Note the spare leads in the lid on the previous photo. The jumpers were connected according to predetermined pattern (pre-shared key) for a given day of the week.
Instructions, in German. Just above this was row where spare bulbs for the unit were kept (and some spares still exist)
A closer view of the keyboard and code selectors.