>Here is the full and final program
I'm going to pull out my chainsaw now.
>void main (void)
main returns int. No excuses. And when you say you'll return int, you'd better actually return a value too. 0 is a good choice.
>for(code='A';code<='Z';code = code+1)
For future reference, only the decimal digits are required to be consecutive. It's possible that there are non-alphabet characters between 'A' and 'Z' depending on the character set. Also, code = code + 1 is pretty verbose. You can get away with ++code .
>printf("%c %d\n", code, code);
You absolutely must include stdio.h if you want to use a function that takes variable arguments. If you don't, you must provide a prototype yourself. Otherwise it's undefined behavior. I suggest getting into the habit of always including the headers that you use stuff from in your programs.
I'd recommend using getchar instead. It's standard, comes with stdio.h, and works everywhere. With getch you have to include the non-standard conio.h, and it's not likely to work in many places.