http://maps.bpl.org/pub/zoom/05/01/0...oup0/3-0-0.jpg
Play around with the numbers in the filename. I think 3 is the zoom level, the last zero looks like it indexes the individual pieces of the map. It doesn't look like you can get it...
And this isn't anything new, Speedfan just happened to add support for it recently. Before that a prog called CoreTemp was used. It's an on-die sensor, meaning the interface is controlled by Intel/AMD, and has been there/been the same...