purple wiki:
[he history of cryptography, 97-shiki-obun In-ji-ki (ä¹ä¸å¼æ¬§æå°åæ©) ("System 97 Printing Machine for European Characters") or Angooki Taipu B (æå·æ©Bå) ("Type B Cipher Machine"), codenamed PURPLE by the United States, was a diplomatic cryptographic machine used by the Japanese Foreign Office during, and just before, World War II. The machine was an electromechanical stepping-switch device.
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