Many thanks for your assistance. The etherium software states that it needs the 15.12 drivers..
I tried the 15.12 radeon drivers, but they fail to work on my HD 6870.
It installs fine, I reboot, and the screen resolution stays crappy, and the radeon settings icon is nowhere to be found and no software can detect an OpenCL on my system.

Newer drivers do install better, setting the screen resolution and "surviving" a reboot.
However the mining software only finds the AMD CPU as the OpenCL source.
 
Regards,
 -turgut