Image: American first purple analog 1

Description: The first analog to the Purple machine (w:Type B Cipher Machine) reconstructed by the US Signals Intelligence Service. The unit contains fourteen 6x25 steping switches. A hand-operated Red analog is also visible. The note to the right describes how a relay welded shut during the Purple unit's first trial and how adding a capacitor fixed the problem. (Pictures taken by Mark Pellegrini at the US National Cryptologic Museum.)
Title: American first purple analog 1
Credit: Own work
Author: Mark Pellegrini
Permission: Own work, share alike, attribution required (Creative Commons CC-BY-SA-2.5)
Usage Terms: Creative Commons Attribution-Share Alike 2.5
License: CC BY-SA 2.5
License Link: https://creativecommons.org/licenses/by-sa/2.5
Attribution Required?: Yes