Download CIT Higher Certificate in Computing Exam - Computer Architecture & Systems Software and more Exams Computer Architecture and Organization in PDF only on Docsity! Cork Institute of Technology Higher Certificate in Computing – Award (National Certificate in Computing – Award) (NFQ – Level 6) Summer 2005 Computer Architecture & Systems Software (Time: 3 Hours) Answer FIVE Questions, including at least one from Section A and at least two from Section B Please use separate answer books for each section. Attached Table of ASCII codes Examiners: Dr. D. Chambers Mr. E. A. Parslow Mr. P. O’Connor Dr. C. Frehill Dr. J. Reynolds Section A: Attempt at least ONE question 1 (a) Compare asynchronous with synchronous transmission. Show how to determine the efficiency of each type. Give an example of one communications technology that uses synchronous transmission, and one that uses asynchronous transmission. Show how to determine the efficiency of each type. (6 marks) (b) Why does it make more sense to send data as frames than to just send it as a stream of bits across the network? (3 marks) (c) An RS232 link is configured as 7 data bits, even parity, 2400 bps. (i) What is the bit duration? (2 marks) (ii) Approximately how many characters would be transmitted per minute? (3 marks) (iii) Accurately sketch the waveform which would correspond to the transmission of the character “C”. (3 marks) (iv) The following bit pattern was received at the receiver 111110110001111111 Was the transmission successful or have any errors occurred in the transmission of the character “C”? (3 marks) 2 2. (a) Given an IP address how may its class be determined? How many valid hosts and networks are there in Classes A, B and C? (3 marks) (b) What are the main advantages of subnetting? (3 marks) (c) A network administrator has been assigned a network address of 204.15.5.0/24. (i) What is the network class? (2 marks) (ii) What is the subnet mask for this network? (2 marks) (iii) The administrator needs to create five subnets – the largest of these must support 28 host addresses. Is this possible on this network? Shown how the administrator could assign the sub networks. (10 marks) 3. (a) What design factors should be taken into consideration when selecting transmission media? (6 marks) (b) Describe, in detail and compare, any two of the following guided transmission media: (i) twisted pair wires (ii) coaxial cables (iii) optical fibre Include in your answer, the principle of operation and the advantages and disadvantages of each. (8 marks) (c) With the aid of a suitable diagram explain the signalling technique Differential Manchester Encoding. Account for the popularity of this technique in lans. (6 marks)
