If the programming is something like attack -> delay -> attack -> delay, then you would attack at the rate it took the program to execute the attack, without delay.
So it would basically give you however fast the computer can computer x amount of attacks while you attacked.
200 though is likely not a valid entry.
I don't think it would necessarily crash the server, or kill anything, depending on how they programmed it. Most stuff would likely instantly die, unless you did like, 1 damage against a monster with several million hp. Then it would take however long the server takes to calculate an attack and damage however many times the monster has hp. (Which could still appear instantaneous if the computer calculates it fast enough.) It could bog down the server if everybody attacked something with high hp at the same time, as it would have quite a bit of data to flow through all at the same time.