There is a close connection between codes and computers. Below I have made a very simple code to decrypt a Caesar shift.  It will give all possible combinations, and you then just have to find the one which makes sense!  You can run this Python code here.

SYMBOLS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

print('CAESAR SHIFT DECRYTION')

print('ENTER THE CODE YOU WANT TO DECRYPT, (USE CAPITAL LETERS)')

code = input('>')

for key in range(1,26):
    translated = ''

    for letter in code:
        if letter in SYMBOLS:
            num=SYMBOLS.find(letter)
            num = num-key
        if num<0:
            num = num+26

        translated = translated + SYMBOLS[num]

    print(key, translated)