I said pioneered. PARC may have created the technology for GUIs, but the Macintosh was the first commercially successful computer to implement a GUI. Andrew Grove may not have created the Microprocessor, but he was the businessman that spread the technology and made it successful. Steve Jobs was crucial in the movement to GUI based computers.
@Gulkan
You said you didn't think they needed to reverse engineer it and you remembered having a manual in 1990 that came with a full printout of the IBM BIOS. My point was the reverse engineering occurred 8 years prior and the internals of the BIOS weren't much of a trade secret anymore.