Two different headings 

The merging of this article would have to be done very carefully if it is to be done correctly as the article has two different headings on the page.

I/O or machine port mechanism - port-mapped I/O relates to actual microprocessors and is a different animal to software or even internet port-mapping.

As shown above, computer port (software) or a software port is different to a TCP port and the distinction should be maintained.