I let a Commodore 64 run for three and a half days straight. 87 billion instructions, 303 billion clock cycles, 5.9 million candidate settings tested. It cracked an Enigma message in German without knowing a single character of the plaintext. New post: Breaking Enigma with Index of Coincidence on a Commodore 64 https://imapenguin.com/2026/03/breaking-enigma-with-index-of-coincidence-on-a-commodore-64/