Assignment 4
Seminar 4 - Exercises
#1. How many cells can be in a computer's main memory if each cell's address can be represented by two hexadecimal digits? What if four hexadecimal digits are used? Explain your answer.
Answer:
Hexadecimal digits is a base 16 number system and it ranges between 0 and F i.e. 0 - 9 and A - F (10 -15). (Table 1 below shows binary, decimal and hexadecimal representation). Two hexadecimal digits will be between 00 and FF and this will make up to 256 cells i.e. 0 – 255 (16 bits) and for four hexadecimal digits will be between 0000 – FFFF and this makes up to 65536 cells i.e. 0 – 65535 (32 bits).
BINARY NUMBERS | DECIMAL NUMBERS | HEXADECIMAL NUMBERS | 0000 | 0 | 0 | 0001 | 1 | 1 | 0010 | 2 | 2 | 0011 | 3 | 3 | 0100 | 4 | 4 | 0101 | 5 | 5 | 0110 | 6 | 6 | 0111 | 7 | 7 | 1000 | 8 | 8 | 1001 | 9 | 9 | 1010 | 10 | A | 1011 | 11 | B | 1100 | 12 | C | 1101 | 13 | D | 1110 | 14 | E | 1111 | 15 | F |
Table 1: Decimal and hexadecimal representation
#2. Suppose that only 50GB of your personal computer’s 120GB hard-disk drive is empty. Would it be reasonable to use CDs to store most of the material you have on the drive as a backup? What about DVDs? Explain your answer.
Answer:
With 120GB of storage and 50GB space free that amounts to 70GB of data to back up, the maximum a CD can take is 700MB (0.7GB) that amounts to 100 CDs. The size of an average DVD-R is about 4.7GB this will make up to 15 DVDs and this makes a lot sense than using 100 CDs.
#3. Suppose three values (x, y, and z) are stored in a machine's memory. Describe the sequence of events (loading registers from memory, saving values in memory, and so on) that lead to the computation of x + y + z. How about (2x) + y?
Answer: I. To compute x + y + z, each of the values must be retrieved from memory and placed into the register, the sum of x and y must be computed placed into the registry and the value of the sum must be added to z and
#1. How many cells can be in a computer's main memory if each cell's address can be represented by two hexadecimal digits? What if four hexadecimal digits are used? Explain your answer.
Answer:
Hexadecimal digits is a base 16 number system and it ranges between 0 and F i.e. 0 - 9 and A - F (10 -15). (Table 1 below shows binary, decimal and hexadecimal representation). Two hexadecimal digits will be between 00 and FF and this will make up to 256 cells i.e. 0 – 255 (16 bits) and for four hexadecimal digits will be between 0000 – FFFF and this makes up to 65536 cells i.e. 0 – 65535 (32 bits).
BINARY NUMBERS | DECIMAL NUMBERS | HEXADECIMAL NUMBERS | 0000 | 0 | 0 | 0001 | 1 | 1 | 0010 | 2 | 2 | 0011 | 3 | 3 | 0100 | 4 | 4 | 0101 | 5 | 5 | 0110 | 6 | 6 | 0111 | 7 | 7 | 1000 | 8 | 8 | 1001 | 9 | 9 | 1010 | 10 | A | 1011 | 11 | B | 1100 | 12 | C | 1101 | 13 | D | 1110 | 14 | E | 1111 | 15 | F |
Table 1: Decimal and hexadecimal representation
#2. Suppose that only 50GB of your personal computer’s 120GB hard-disk drive is empty. Would it be reasonable to use CDs to store most of the material you have on the drive as a backup? What about DVDs? Explain your answer.
Answer:
With 120GB of storage and 50GB space free that amounts to 70GB of data to back up, the maximum a CD can take is 700MB (0.7GB) that amounts to 100 CDs. The size of an average DVD-R is about 4.7GB this will make up to 15 DVDs and this makes a lot sense than using 100 CDs.
#3. Suppose three values (x, y, and z) are stored in a machine's memory. Describe the sequence of events (loading registers from memory, saving values in memory, and so on) that lead to the computation of x + y + z. How about (2x) + y?
Answer: I. To compute x + y + z, each of the values must be retrieved from memory and placed into the register, the sum of x and y must be computed placed into the registry and the value of the sum must be added to z and
References: I. J Glenn Brookshear (2012) Computer.Science.An.Overview.11th.Edition II. Myce (2005) Actual Size of DVD-R 4.7GB? (Online) Available at http://club.myce.com/f33/actual-size-dvd-r-4-7gb-139256/ (Accessed on 3 October 2012) III. wikipedia (2012) Megabyte (Online) Available at http://en.wikipedia.org/wiki/Megabyte (Accessed on 3 October 2012) IV. Dreamincode (2007) Logic Design Assignment (Online) Available at http://www.dreamincode.net/forums/topic/24304-logic-design-assignment/ (Accessed on 3 October 2012)