Obviously a smart move that made him insanely wealthy. But how do you do that in business. How do you say, "Yeah, you know that job you hired me to do? Well I did it but I changed my mind and I'm not going to give it to you. But hey, I would be happy to license it to you if you pay me for every computer that uses it."
Is there a book somewhere that explains how that conversation and negotiation REALLY went? Because I don't get how you can accept a job and then re-negotiate the rights after you have already been hired to do the job. Or was that the terms he negotiated during the hiring. And if so, why would IBM hire him in the first place when they could have looked elsewhere for some one that would both write it AND sell them the rights?