1. Computer memory

1.1 Memory as seen by the programmer

Ever since the first computers, the needs of program developers have always been the same. They can be summed up schematically as follows:

• have as much memory space as possible for their programs, without having to worry about the size and nature of the physical memories actually used, i.e. with today's technology semiconductor memories and magnetic disks;

• use the computer as if they were the only users. This implies that the execution of their programs is protected against the voluntary or involuntary interactions of other programs, whether their own or those of other users.

In fact, the first aspect corresponds to the unbridled evolution...