Use this machine to write in secret code. First, enter a secret key of seven characters (letters and numbers only). Then type your message. Each time you press a letter key, the dial will turn so that the arrow at the top points at that letter. Then the arrow on the inside will turn to point at the coded letter. If you send someone a message encoded this way, they can type the coded message in, and the original message will come out; but only if they enter the same secret key. The key is case-sensitive (upper- and lowercase letters are different, so 'A' is not the same as 'a'), but the message letters are not. Try entering this key: abcdefg ... then type this encoded message in: OPRX IPR DMUA DTOLK UXNQCK DDOCKUVE ... and see what comes out! You can use the left-arrow key to backspace if you make a mistake. Use the green flag button to reset the machine.
Update: Now you can use the left-arrow key to backspace. This is a revised version of my earlier code machines, with the addition of a key to advance the arrow in an irregular pattern. The key determines the pattern of tabs on four pairs of rotors. If the tabs of a pair are different, that pair sets its bit of the step value, otherwise the bit is cleared. The four bits make a value from zero to 15, which is used to advance the arrow pointer. Many thanks to turkey3 for a post about sensing case.
