Hi,
That has an AMD Sempron 3000+ 2.0 GHz (Socket A) and a 333 MHz FSB. It takes 184 pin DDR333 PC2700 RAM. You can add a 512 MB stick, but it isn't guaranteed to work. Your best bet is to add 2 x 256 MB sticks or 2 x 512 MB sticks in a matched pair so that you will have no issues.
That has an AMD Sempron 3000+ 2.0 GHz (Socket A) and a 333 MHz FSB. It takes 184 pin DDR333 PC2700 RAM. You can add a 512 MB stick, but it isn't guaranteed to work. Your best bet is to add 2 x 256 MB sticks or 2 x 512 MB sticks in a matched pair so that you will have no issues.