Problem 1
What are the advantages and disadvantages of using a very large memory cell size, say, \(W\) \(=64\) instead of the standard size \(W=8\) ? If each integer occupies one 64-bit memory cell and is stored using sign/magnitude notation, what are the largest (in terms of absolute value) positive and negative integers that can be stored? What if two cells are used to store integers?
Problem 2
At a minimum, how many bits are needed in the MAR with each of the following memory sizes? a. 1 million bytes b. 10 million bytes c. 100 million bytes d. 1 billion bytes
Problem 4
Explain what use read-only memory (ROM) serves in the design of a computer system. What type of information is kept in ROM, and how does that information originally get into the memory?
Problem 6
Assume a 24-bit MAR that is organized as follows: Row select lines Column select lines 12 bits 12 bits What is the maximum size of the memory unit on this machine? What are the dimensions of the memory, assuming a square twodimensional organization?
Problem 7
Assume that our MAR contains 20 bits, enabling us to access up to \(2^{20}\) memory cells, which is \(1 \mathrm{MB}\), but our computer has \(4 \mathrm{MB}\) of memory. Explain how it might be possible to address all \(4 \mathrm{MB}\) memory cells using a MAR that contains only 20 bits.
Problem 8
Assume that our MDR register is 16 bits wide while our machine language instructions are 32 bits wide. How might the fetch phase of the Von Neumann cycle have to be changed from what was described in the text?
Problem 9
Assume that a 1 gigaflop machine is connected to a printer that can print 780 characters per second. In the time it takes to print 1 page ( 65 lines of 60 characters per line), how many floating-point operations can the machine perform?
Problem 10
. Assume that we have an arithmetic/logic unit that can carry out 20 distinct operations. Describe exactly what kind of multiplexer circuit would be needed to select exactly one of those 20 operations.
Problem 11
A CISC-style instruction set has a large number of high-level instructions that perform highly complex operations in a single step. What would be the major advantages of such a design? What would be some of the primary disadvantages?
Problem 17
Discuss some situations in which a sequential access storage device such as a tape could be a useful form of mass storage.
