In order to get the HDMI screen output to use the full screen, I had to create a file /boot/config.txt
In this file I set the following options.
The mode sets it to 1080p60
The drive sets it to forced HDMI rather than dvi I think.
The disable overscan does what it says. - I needed to do this to make it appear on the HDMI input on the TV.
Really useful page for these options is http://elinux.org/RPi_config.txt