Could I get around a copyright by changing one small thing
<p>I am trying to make a computer program that simulates another computer. I want to simulate something called the Scott CPU (from <a href="http://buthowdoitknow.com/" rel="nofollow noreferrer">here</a>). Could I change a small thing about it and not have to ask for permission to use it?</p>

<p>The copyright holder has the rights in whatever he created. If you have created something new based on his idea, the law will generally not be interested; but if your expression is recognisably a copy with a few changes, he can prevent publication or demand royalties. If you are uncertain which side of the line you fall, you should ask a lawyer (or, more cheaply, write to the author and ask if he objects). </p>

intellectual-property