Originally Posted by airbozo
Good point, however the courts have ruled that you cannot trademark a number which is why they changed the name of the i586 to the "Pentium".
They tried, though.
When AMD came out with its own version of the 386, Intel sued them and said that they had only given AMD a license to produce the 808x and 286 series processors, while AMD said they could use their x86 license to make any processors they wanted that used that instruction set. AMD won the case, and by that time, they were also making their own version of the 486 as well. AMD's victory massively undercut the huge markups that Intel was able to charge for their 32-bit x86 CPU's.
Intel, during the time when AMD was developing its 386, actually tried to trademark the term "AMD 386" to keep AMD from using it, but the feds disallowed it. When they were developing what became known as the Pentium, Intel tried to trademark "80586" and just plain "586" and were denied, because as you said, you can't trademark a number. That's when Intel came up with the Pentium name.