My memory isn't so good anymore. So as a note to myself below is the Ubuntu PPA and install commands for the excellent Playstation 2 emulator, PCSX2. I installed it under 13.10 (saucy), but I had to lie to the sources file and say I was 13.04 (raring). PCSX2 is written for 32-bit systems but when you install it on 64-bit it downloads and installs the 32-bit libraries needed to run it.
sudo add-apt-repository ppa:gregory-hainaut/pcsx2.official.ppa
sudo apt-get update
sudo apt-get install pcsx2-unstable