Dave the Web Guy's server configuration has changed numerous times over the years. Chances are the content you're looking for is still here, just not at the URL address you've stumbled in with.
Your visit attempt has been logged and will indicated to Dave exactly what you were looking for so that he can add the new location to a redirect table. The best advice in the meantime is to look at the Google cache copy of what you came for (if one exists), or to simply try your URL link later. It usually takes Dave 24 to 48 hours to notice these errors and subsequently update the redirection table. After the table has been updated, the URL you just used will take you to the new content location, its best equivalent, or, an explanation page.
If you're really desperate to find the content your looking for now, please see Dave's contact page for contact options.