GlobalMapper v13 help

GM is now up to v20, and I'm using v13.?ÿ It's entirely adequate for my needs.?ÿ When I click on "Online Help..." I get a Not Found error.?ÿ I know there are (were) html help files for offline use, but I cannot find them on my PC.?ÿ When I reached out to Bluemarble, I got this message:

"Thank you for contacting Blue Marble Geographics. Because v13 is a legacy version, maintenance and support have expired for your version of the software. Blue Marble provides license support only for the current version of Global Mapper.?ÿ We no longer provide licensing assistance or distribute the installation files for Global Mapper v13.?ÿ?ÿTo receive maintenance and support for your software, we encourage you to upgrade to our current version of Global Mapper. "

Does anyone here have "GlobalMapperHelp.zip"??ÿ (I think that's the filename.)

Thanks!