When a new version of OS X comes along I dutifully download it, note the obvious changes and carry on as usual. I seldom have problems (fingers crossed as always) but I confess that I do not delve into the nitty gritty of all the changes under the bonnet. Sometimes a new feature grabs my attention and is immediately useful, such as the very nifty split-screen mode which I covered last week. It’s good, then, to have all the major changes assembled and presented in an easy-to-read format. Over at T3 Online they’ve delved under into the small print and come up with the 75 hidden secrets of El Capitan. I can recommend the article if you want to make the most out of your new operating system.