Unix uses the same memory as any other operating system. This includes either physical or virtual memory.
Most UNIX implementations use the same type of addressing as other modern Operating Systems, which include page translation, segmentation, and virtual memory addressing.
The memory is the function of the brain.
Vitual Memory
Yes, Unix is system software. It is a kind of operating system.
There is no traditional 'execute' command in Unix.
It is possible to use BSD software on Unix systems. It is possible but many do not and they use other softwares on Unix systems beside the BSD software.
You don't mention what kind of 'request'.
It Depends what Kind Of Camera You Have
Your question is too vague; what kind of graphic and what do you intend to do with it? Either with svgalib or X11 (the latter is the good choice;)
http://www.edgetechcorp.com/memory/upgrade.asp?cid=23155
Unix can be used on a large number of mainframes, servers, and workstations. If you would like to use a certified UNIX system on commodity hardware, Solaris 10 can be downloaded free of charge for non-commercial use.
In fact what you can use any kind of memory card, but you have to choose the best quality. I think wii memory card is very good. If you are interested in it, you may have a look. http://www.dinodirect.com/Wii-Accessories/Wii-Memory-Cards/