Method and apparatus for performing multi-function and effectively managing memories

A multi-function apparatus includes a basic memory, a socket, and a controller. The basic memory includes at least a first image memory area for a copying function and a second image memory area for a facsimile function. The socket connects an add-on expansion memory. The controller arranges memory assignments of the basic memory in accordance with a first memory map to perform operations of the copying and facsimile functions when the expansion memory is not mounted to the socket. The controller rearranges the memory assignments of the basic memory and of the expansion memory with an effect of expanding the first and second image memory areas in accordance with a second memory map to perform the operations of the copying and facsimile functions when the expansion memory is mounted to the socket.