iMac g4 15" 1gig - want to max out ram...

I purchased my girlfriend a iMac g4 15" 1gig and right now it has 2 - 256 sticks at 2700.

I know I can upgrade the one unit that is on the bottom - but if I'm thinking correctly the one 256 unit I can not get to...

Is it possible to buy a 768 stick or a 1gig stick?

What are my options here - both on apple.com and cruical.com they only offer a 512 stick!!

thanks for the help.

Would it be possible to use a 512 stick from my g4 14" 1.33 ibook in this imac?

A 768MB stick doesn't exist. technically, you could put a 1GB stick in it, but I'm not sure if it will recognise more than 512MB. Thelimitation, if there is any, is not physical, but a memory controller issue.
The second 256MB stick is a normal module, not SODIMM. But to change that one, you need to open the iMac. If you are not technically skilled and know what you do, I would not recommand that. Because it's is pretty fiddle to put together again, and you need to remove and reapply some heat transfer paste.

The 1.33GHz iBook uses PC2100 memory, your iMac needs PC2700. Sometimes, they put PC2700 memory in iBooks, so if you're lucky, you might be able to use it. Check the module, the specs should be written on it. If it is PC2700, then you can put it in the iMac and will have a total of 768MB.

yeah the slot thats easy to get to wont take more than 512