I know this has been discussed probably a few hundred times but I am not finding my answer in the search archives. I have a 1.5 powerbook 15" g4. with 1.5g of ram. I want to upgrade this. What is the maximum ram I can put in this machine? I called macmall.com and they only offer a 1gb stick. I took my cover off the back of my powerbook and I have a 1.5 stick inside of it. Plus the built in (I am assuming that the 512mb is built in, Correct?) then why is it only saying 1.5 gb of Ram? What do I need and where on Macmall can I find larger ram for this notebook. Thanks in advance and also I did try to search I just could not find the answer I was looking for. Here is what I am working with.