I understood that in certain Windows XP programs, like Photoshop, there is something called "scratch disks". What I understood that this means, and please correct me if I'm wrong, is that Photoshop manages its own virtual memory on the hard-drive, instead of letting Windows manage it. I understood that the reason for this is some limitation by Windows XP on how much total memory a process can take, regardless of HD space. I think it's around 3 GB. Did I get it right so far?
I am making an application in Python for running simulations. It will take a lot of memory, and will run on Windows XP. Is it possible for it to use scratch disks? How?
Scratch disks will benefit your application in the case that it works with very big files, 
Is that the case? 
If not, then i don't think you may find something that will benefit your application in scratch disks.
Scratch disks in Python?