13 Feb
2014
13 Feb
'14
10:36 a.m.
On Thu, 13 Feb 2014 12:19:35 +0000, Peter Corlett <abuse at cabal.org.uk>
wrote:
Do remember that the amount of memory supported in a
system depends on the size
of the physical and virtual address spaces. The virtual address space
corresponds to the size of a pointer, and the physical address space
corresponds to the number of pins actually coming out of the CPU package.
Paging hardware allows the physical address space to be larger than virtual.
Virtual memory and paging was originally invented to allow the *virtual*
address space to be larger than the physical address space.
It does work both ways of course, but the original idea was in some old
machines of the 1950s to allow extending the address space by using disk
storage. The Atlas, for example.