The Speaker of the Maine House of Representatives between 1979 and 1980 was H. R. Mansur. This information was found on the Maine State Legislature's website, which provides a list of speakers of the Maine House of Representatives. The 109th House, which served during the 1979-1980 term, was led by H. R. Mansur as the Speaker. For more information, you can refer to the Maine State Legislature's official website.