MSHS 2019 P1

Class/ Index Number / Centre Number/ ‘O’ Level Index Number / Name MARIS STELLA HIGH SCHOOL PRELIMINARY EXAMINATION SECONDARY FOUR COMPUTING 7155/01 Paper 1 Written 28 Aug 2019 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your class, index number and name in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid. Approved calculators are allowed. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. You should show all your working. The total number of marks for this paper is 80. For Examiner’s Use This document consists of 12 printed pages. 80

2 1 Insert six of the following words or numbers about computers and data in the correct place in the text below. 2 10 16 analogue binary denary digital hexadecimal While ________________________ data is transmitted via fibre optical cables, a computer cannot process this type of data. For a computer to be able to process data, it needs to be converted to ________________________ data. As humans, we mostly use a ______________________ number system; this is a base ______________________ number system. Computers use a ______________________ number system; this is a base ______________________ number system. [6] 2 The three binary numbers in the registers X, Y, Z were transmitted from one computer to another. Parity bit Register X 1 0 0 1 1 0 0 0 Register Y 0 1 1 0 0 1 1 1 Register Z 1 0 0 1 1 0 0 1 One binary number was transmitted incorrectly. This is identified through the use of a parity bit. Identify which register contains the binary number that was transmitted incorrectly. Explain the reasons for your choice. The binary number that was transmitted incorrectly is in Register ……………… Explanation ……………………………………………………………………………………... ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. [4]

3 3 John is writing a program using a high-level language. The program will be published and sold for a profit. (a) John uses an interpreter when creating the computer program. State three features of an interpreter. Feature 1 ………………………………………………………………………………... ……………………………………………………………………………………………. Feature 2 ………………………………………………………………………………... ……………………………………………………………………………………………. Feature 3 ………………………………………………………………………………... …………………………………………………………………………