You will be given a string as an argument. You need to convert that string to upper case. But you can't use any built in method or function nor any external programs.
No use of built in methods or functions or external programs. Only arithmetic, bitwise, logical operators, regex, replace, split, join, ASCII codes are allowed.
The string as an argument. The string can contain spaces and special characters.
The string in upper case.
This is code-golf so shortest code wins.