Early Systems

In the early days, building computer systems was easy. Why do you ask? Because users didn’t expect much. It is those darned users with their expectations of “ease of use”, “high performance”, “reliability”, etc., that really have led to all these headaches. Next time you meet one of those computer users, thank them for all the problems they have caused.

From the perspective of memory, early machines didn’t provide much of an abstraction to users. Basically, the physical memory of the machine looked something like what you see in the figure below: