No need to argue, since you're both right. Rwaliany is using the actual definition of two's complement (the highest bit represents the opposite of what it does in an unsigned int (so 10000000 = -128 if it's a signed bit and +128 if it's unsigned)). Rbayer is using an easy shortcut to calculating the two's complement.

A skillful programming isn't limited by the law, either. Wait, what I meant to say was that a skillful programmer is limited by the language, at least when we're talking PBASIC. I'd like to see someone who can make their robot do differentiation. If you're talking QBASIC versus C, then it doesn't matter. PBASIC simply doesn't do alot of things. The difference is in the context. PBASIC could do anything a person could ever want their robot to do, if they're smart enough and can devote the time to doing it. If you couldn't do everything feasible/useful I think FIRST would change things.