Would Microsoft be a large corporation if copyright in the early 80s prevented Compaq from copying the "structure, sequence, and organization" of the IBM BIOS c

Would Microsoft be a large corporation if copyright in the early 80s prevented Compaq from copying the "structure, sequence, and organization" of the IBM BIOS chip on the original IBM PC? They made the big money on DOS from selling to clone manufacturers -- IBM paid a flat rate on MS-DOS.