So there are a lot of useful reference links in these forums to https://arduino-info.wikispaces.com/ e.g. https://arduino-info.wikispaces.com/RelayIsolation BUT that site has shutdown 
Would it be possible to replace all these links automatically to a "waybackmachine" https://web.archive.org/ version?
e.g. arduino-info - RelayIsolation
I think the site has just moved and the like your looking for is now here.
Hi @Riva,
THANKS for noticing this. I will try to find better ways of handling this...
The site can ALWAYS be found by starting at http://ArduinoInfo.Info
For a couple of months the "Wikispaces" provider had an automatic link to the new site. Then they stopped that. NOT friendly!
I will talk to the Forum admins here about the best thing to do...