[BioC] increase R memory

[crispi@igb.cnr.it]

I am using the new R version (R 2.1.1) but when I try to use gcrma package the
program stops to work.
I have the following error messages regarding the failure to obtain enough memory

"cannot allocate vector of size...." 

" reached total allocation 510 Mega" 
 
How could I enhance the program memory?
What is the right syntax?

thank you for your help

regards

stefania