6.1 Introduction
RAM /abr./: Rarely Adequate Memory, because the more memory a computer has, the faster it can produce error messages.
-Anonymous
640K [of memory] ought to be enough for anybody.
-Bill Gates
Most computers are built using the Von Neumann model, which is centered on memory. The programs that perform the processing are stored in memory. We examined a small 4 x 3-bit memory in Chapter 3 and we learned how to address memory in Chapters 4 and 5. We know memory is logically structured as a linear array of locations, with addresses from 0 to the maximum memory size the processor can address. In this chapter we examine the various types of memory and how each is part of the memory hierarchy system. We then look at cache memory (a special high-speed memory) and a method that utilizes memory to its fullest by means of virtual memory implemented via paging.
