Ian McNaught-Davis
'Mac', presenter of a number of early 1980s BBC Computer shows is (as far as I can work out) very much alive and kicking! Spurred on by watching a few of the old shows a couple of years ago, myself and like minded friends decided to check what he was up to nowadays...
After watching a show from the 1960s of him climbing The Old Man of Hoy (on Orkney) we discovered that Ian McNaught-Davis is a big cheese in the world of mountaineering and is a patron of the British Mountaineering Council. He's mentioned in this article from only a few months ago:
http://www.thebmc.co.uk/modules/article.aspx?id=4585