Get the numbers off the top of the Athlon Case 
This is my T-bird # 710038016953 
Not sure what the first 2 are
The "00" stands for the year of manufacture, so this was manufacuted 
in 2000( "00" would be 2000) 
The "38" after "00" is the week of manufacture. 
So, this Athlon  is a week 38 ,2000 year. 
The rest of the numbers are all unknown, but there are plenty of rumors about them.
You will need to open it up to find out what core you have. 
The first row of # that start with AMD,download this pdf file and it will explain them to you
Link