Left Green button is Advance
Right Green button is Select
Log Mode is indicated by a little book in the upper left
Hit the Left Key 4 times
Then hight Right key to enter
The most recent dive is first

Each dive has three log screens.  The first displays the date/time started, the second NItrogen related data, and the thrid Oxygen related data.  If F02 was set for 'Air' for that dive, the 02 screen will only display 'FO2' and 'Air'