5 replaced http://scifi.stackexchange.com/ with https://scifi.stackexchange.com/ edited Apr 13 '17 at 12:43 Since the only data NASA can send is the direction the camera is facing, Mark comes up with a system where they can point at cards with alphabet characters on them to type messages. But using the letters 'a-z' would be impractical. To quote the book (from this answerthis answer, over on scifi.se): Since the only data NASA can send is the direction the camera is facing, Mark comes up with a system where they can point at cards with alphabet characters on them to type messages. But using the letters 'a-z' would be impractical. To quote the book (from this answer, over on scifi.se): Since the only data NASA can send is the direction the camera is facing, Mark comes up with a system where they can point at cards with alphabet characters on them to type messages. But using the letters 'a-z' would be impractical. To quote the book (from this answer, over on scifi.se): Tweeted twitter.com/StackCodeGolf/status/837625016959307776 occurred Mar 3 '17 at 11:25 4 added 57 characters in body edited Mar 2 '17 at 18:01 Jonathan Allan 60.2k55 gold badges4444 silver badges187187 bronze badges Input: CROPS? ASCII: 43 52 4F 50 53 3F Worked Example: 5 * 21 = 105 -1 * 21 = -21 2 * 21 = 42 -3 * 21 = -63 2 * 21 = 42 -6 * 21 = -126 7 * 21 = 147 -5 * 21 = -105 5 * 21 = 105 -2 * 21 = -42 0 * 21 = 0 -5 * 21 = -105 1 * 21 = 21 Result: [105 -21 42 -63 42 -126 147 -105 105 -42 0 -105 -21] Input: DDD ASCII: 44 44 44 Worked Example: 5 * 21 = 105 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 -5 * 21 = -105 Result: [105, 0, 0, 0, 0, 0, -105] Input: Hello world! ASCII: 48 65 6c 6c 6f 20 77 6f 72 6c 64 21 Worked example: 5 * 21 = 105 4 * 21 = 84 -2 * 21 = -42 -1 * 21 = -21 1 * 21 = 21 6 * 21 = 126 -6 * 21 = -126 6 * 21 = 126 -6 * 21 = -126 -8 * 21 = -168 4 * 21 = 84 -2 * 21 = -42 7 * 21 = 147 0 * 21 = 0 -1 * 21 = -21 -8 * 21 = -168 -8 * 21 = -168 -5 * 21 = -105 4 * 21 = 84 6 * 21 = 126 -6 * 21 = -126 -2 * 21 = -42 -2 * 21 = -42 -1 * 21 = -21 -2 * 21 = -42 Result: [105 84 -42 -21 21 126 -126 126 -126 -168 84 -42 147 0 -21 -168 -168 -105 84 126 -126 -42 -42 -21 -42]  Input: CROPS? ASCII: 43 52 4F 50 53 3F Worked Example: 5 * 21 = 105 -1 * 21 = -21 2 * 21 = 42 -3 * 21 = -63 2 * 21 = 42 -6 * 21 = -126 7 * 21 = 147 -5 * 21 = -105 5 * 21 = 105 -2 * 21 = -42 0 * 21 = 0 -5 * 21 = -105 1 * 21 = 21 Result: [105 -21 42 -63 42 -126 147 -105 105 -42 0 105 -21] Input: DDD ASCII: 44 44 44 Worked Example: 5 * 21 = 105 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 -5 * 21 = -105 Result: [105, 0, 0, 0, 0, 0, -105] Input: Hello world! ASCII: 48 65 6c 6c 6f 20 77 6f 72 6c 64 21 Worked example: 5 * 21 = 105 4 * 21 = 84 -2 * 21 = -42 -1 * 21 = -21 1 * 21 = 21 6 * 21 = 126 -6 * 21 = -126 6 * 21 = 126 -6 * 21 = -126 -8 * 21 = -168 4 * 21 = 84 -2 * 21 = -42 7 * 21 = 147 0 * 21 = 0 -1 * 21 = -21 -8 * 21 = -168 -8 * 21 = -168 -5 * 21 = -105 4 * 21 = 84 6 * 21 = 126 -6 * 21 = -126 -2 * 21 = -42 -1 * 21 = -21 -2 * 21 = -42 Result: [105 84 -42 -21 21 126 -126 -168 84 -42 147 0 -21 -168 -168 -105 84 126 -126 -42 -21 -42]  Input: CROPS? ASCII: 43 52 4F 50 53 3F Worked Example: 5 * 21 = 105 -1 * 21 = -21 2 * 21 = 42 -3 * 21 = -63 2 * 21 = 42 -6 * 21 = -126 7 * 21 = 147 -5 * 21 = -105 5 * 21 = 105 -2 * 21 = -42 0 * 21 = 0 -5 * 21 = -105 1 * 21 = 21 Result: [105 -21 42 -63 42 -126 147 -105 105 -42 0 -105 21] Input: DDD ASCII: 44 44 44 Worked Example: 5 * 21 = 105 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 -5 * 21 = -105 Result: [105, 0, 0, 0, 0, 0, -105] Input: Hello world! ASCII: 48 65 6c 6c 6f 20 77 6f 72 6c 64 21 Worked example: 5 * 21 = 105 4 * 21 = 84 -2 * 21 = -42 -1 * 21 = -21 1 * 21 = 21 6 * 21 = 126 -6 * 21 = -126 6 * 21 = 126 -6 * 21 = -126 -8 * 21 = -168 4 * 21 = 84 -2 * 21 = -42 7 * 21 = 147 0 * 21 = 0 -1 * 21 = -21 -8 * 21 = -168 -8 * 21 = -168 -5 * 21 = -105 4 * 21 = 84 6 * 21 = 126 -6 * 21 = -126 -2 * 21 = -42 -2 * 21 = -42 -1 * 21 = -21 -2 * 21 = -42 Result: [105 84 -42 -21 21 126 -126 126 -126 -168 84 -42 147 0 -21 -168 -168 -105 84 126 -126 -42 -42 -21 -42]  3 edited body edited Mar 2 '17 at 16:12 DJMcMayhem♦ 42.3k1212 gold badges160160 silver badges330330 bronze badges Input: CROPS? ASCII: 43 52 4F 50 53 3F Worked Example: 5 * 21 = 105 -1 * 21 = -21 2 * 21 = 42 -3 * 21 = -63 2 * 21 = 42 -6 * 21 = -126 7 * 21 = 147 -5 * 21 = -105 5 * 21 = 105 -2 * 21 = -42 0 * 21 = 0 -5 * 21 = -105 -1 * 21 = -21 Result: [105 -21 42 -63 42 -126 147 -105 105 -42 0 105 -21] Input: DDD ASCII: 44 44 44 Worked Example: 5 * 21 = 105 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 -5 * 21 = -105 Result: [105, 0, 0, 0, 0, 0, -105] Input: Hello world! ASCII: 48 65 6c 6c 6f 20 77 6f 72 6c 64 21 Worked example: 5 * 21 = 105 4 * 21 = 84 -2 * 21 = -42 -1 * 21 = -21 1 * 21 = 21 6 * 21 = 126 -6 * 21 = -126 6 * 21 = 126 -6 * 21 = -126 -8 * 21 = -168 4 * 21 = 84 -2 * 21 = -42 7 * 21 = 147 0 * 21 = 0 -1 * 21 = -21 -8 * 21 = -168 -8 * 21 = -168 -5 * 21 = -105 4 * 21 = 84 6 * 21 = 126 -6 * 21 = -126 -2 * 21 = -42 -1 * 21 = -21 -2 * 21 = -42 Result: [105 84 -42 -21 21 126 -126 -168 84 -42 147 0 -21 -168 -168 -105 84 126 -126 -42 -21 -42]  Input: CROPS? ASCII: 43 52 4F 50 53 3F Worked Example: 5 * 21 = 105 -1 * 21 = -21 2 * 21 = 42 -3 * 21 = -63 2 * 21 = 42 -6 * 21 = -126 7 * 21 = 147 -5 * 21 = -105 5 * 21 = 105 -2 * 21 = -42 0 * 21 = 0 5 * 21 = 105 -1 * 21 = -21 Result: [105 -21 42 -63 42 -126 147 -105 105 -42 0 105 -21] Input: DDD ASCII: 44 44 44 Worked Example: 5 * 21 = 105 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 -5 * 21 = -105 Result: [105, 0, 0, 0, 0, 0, -105] Input: Hello world! ASCII: 48 65 6c 6c 6f 20 77 6f 72 6c 64 21 Worked example: 5 * 21 = 105 4 * 21 = 84 -2 * 21 = -42 -1 * 21 = -21 1 * 21 = 21 6 * 21 = 126 -6 * 21 = -126 6 * 21 = 126 -6 * 21 = -126 -8 * 21 = -168 4 * 21 = 84 -2 * 21 = -42 7 * 21 = 147 0 * 21 = 0 -1 * 21 = -21 -8 * 21 = -168 -8 * 21 = -168 -5 * 21 = -105 4 * 21 = 84 6 * 21 = 126 -6 * 21 = -126 -2 * 21 = -42 -1 * 21 = -21 -2 * 21 = -42 Result: [105 84 -42 -21 21 126 -126 -168 84 -42 147 0 -21 -168 -168 -105 84 126 -126 -42 -21 -42]  Input: CROPS? ASCII: 43 52 4F 50 53 3F Worked Example: 5 * 21 = 105 -1 * 21 = -21 2 * 21 = 42 -3 * 21 = -63 2 * 21 = 42 -6 * 21 = -126 7 * 21 = 147 -5 * 21 = -105 5 * 21 = 105 -2 * 21 = -42 0 * 21 = 0 -5 * 21 = -105 1 * 21 = 21 Result: [105 -21 42 -63 42 -126 147 -105 105 -42 0 105 -21] Input: DDD ASCII: 44 44 44 Worked Example: 5 * 21 = 105 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 0 * 21 = 0 -5 * 21 = -105 Result: [105, 0, 0, 0, 0, 0, -105] Input: Hello world! ASCII: 48 65 6c 6c 6f 20 77 6f 72 6c 64 21 Worked example: 5 * 21 = 105 4 * 21 = 84 -2 * 21 = -42 -1 * 21 = -21 1 * 21 = 21 6 * 21 = 126 -6 * 21 = -126 6 * 21 = 126 -6 * 21 = -126 -8 * 21 = -168 4 * 21 = 84 -2 * 21 = -42 7 * 21 = 147 0 * 21 = 0 -1 * 21 = -21 -8 * 21 = -168 -8 * 21 = -168 -5 * 21 = -105 4 * 21 = 84 6 * 21 = 126 -6 * 21 = -126 -2 * 21 = -42 -1 * 21 = -21 -2 * 21 = -42 Result: [105 84 -42 -21 21 126 -126 -168 84 -42 147 0 -21 -168 -168 -105 84 126 -126 -42 -21 -42]  2 fix "Hello world!" test case edited Mar 1 '17 at 21:31 ETHproductions 45.2k55 gold badges7878 silver badges225225 bronze badges 1 asked Mar 1 '17 at 20:42 DJMcMayhem♦ 42.3k1212 gold badges160160 silver badges330330 bronze badges