He bought DOS for $50,000 and tried to sell it to IBM for a huge profit but they weren't interested because they already ( OS-1) so he packaged it as MICROSOFT DOS and gave it away with new PCs. Made him billions in the long run!
Seriously? That PBS show clearly stated his selling DOS to IBM was the cornerstone of his wealth.
Maybe I remembered it wrong,and what he did was use his family connections to get IBM to adopt DOS as their operating system,and that gave him the jump start he needed to sell it to other manufacturers and to consumers?
After all,it's been a long time since I saw that show.