= = 170

Transcription

1 Section 1 20 marks. In your exam, this section should take 20 minutes to complete. The questions below should take no more than 30 mins. 1. Convert the value 52 into an 8-bit binary number. Show your working Convert the binary number into a decimal value. Show your working = = State which bus takes information to and from main memory. 1 Data bus 4. State which bus is used to identify memory locations to be read from or written to by the processor. 1 Address bus 5. The processor is made up of three distinct areas. Name them and describe their functions. 4 Arithmetic and Logic Unit (ALU) - carries out all calculations and makes decisions. Registers holds data and instructions after being transferred from memory into the processor OR a temporary storage location within the processor Control Unit synchronises the timing of the events carried out by the processor OR sends out signals that fetch/execute instruction from main memory 6. Files can be sent by . State the type of file stored in 5 avi Video gif Animation mp4 Video mp3 jpg Music(sound) graphic 7 The following data is being used by a program Address - 1 High Street Number of occupants 5 furnished - False (a) The address has been stored as a text field type. Explain why this is the correct field type to use. 1 The address contains both numbers and letters this is the only field type that can include both types (b) The number of occupants field has been stored as an integer field type. Explain why it is more efficient to store the number 1 as an integer than it would be to store it as a text character. 2

2 Integer can store the number in 3 bits(101) but to store it as a character would require a minimum of 8 bits (ASCII) (c) Explain why the furnished field value of False should be stored as type Boolean rather than as type text. 2 Using a text data type will use more storage than a Boolean type because a Boolean field could use as little as one bit (but a TEXT field will use at least 5 bytes one for each character). 8. The pseudocode below shows how a program stores information about pupils and their prelim marks. Line 1. SET pupilname TO [ Billy Bragg, Adam Ant, Aladin Sane, Suzie Souix ] Line 2. SET pupilmark TO [85, 26, 70, 84] State the most suitable data structure and data type for storing both the pupilname and the pupilmark. 3 data structure data type pupilname Array String pupilmark Array Integer 9 A program stores the weekly takings for the school canteen over a 12-week period. State a suitable data structure and data type for storing the weekly takings. Data structure = Array Data type = real (single) 2 10 Line 1. Private Sub get_pupil_results Line 2. prompts user to enter name and mark Line 3. n = Inputbox( Please enter pupil name ) Line 4. m = Inputbox( Please enter pupil mark ) Line 5. End Sub The above code is readable thanks to line 2. State two other techniques which could be used to make code more readable and explain why they improve the readability of code. Indentation - Related command words or operators are at the same level of indentation OR Can see the structure of code (what is inside loops, if statements etc.) Meaningful variable names - helps the programmer to analyse the logic of the program/ find errors 11 A web page can be found using the URL: 2 N5-computing/index.php (a) Identify the folder being accessed. 1 N5-computing (b) State the protocol being used by this URL. 1 Hyper text transfer protocol

3 12 A graphic is stored using the following data: <square side = 100 ;style = fill:rgb(255,0,0);line-width:1;line-col:rgb(0,0,255) > (a) State the type of graphic being stored. 1 Vector (b) State one advantage of storing a graphic in this format. 1 Resolution independent Require less space than equivalent bitmap Able to edit vector details without altering other elements of image OR can edit at object level 13 Part of a database used to store information about laptops is shown below. B Describe how the data above has been sorted. 2 Data is sorted on: Price (ascending) and Processor Speed (Hz) (descending) 1 mark for each sort field with direction, order of fields is important

4 14 The home page for the web site Every News is shown below. It provides access to the four main sections of the website: World News, UK News, Strange News and Sport. B (a) During testing the login button is checked to make sure the script is executed correctly and the data entered is validated correctly. Describe two other tests that should be carried out during testing. 2 Checked links are valid. Examine visual layout of page for errors (b) The website URL is State the meaning of the term URL. 1 Uniform Resource Locator (c) Using examples from the web page shown, explain the difference between an internal and external hyperlink. 2 The topic links will be internal links so will remain within the domain/site The links to news web sites are external links as they go outside the domain/ site (d) It is important that web pages are as accessible as possible. Describe two features of good design that could be used to improve accessibility. 2 Responsive design ensuring access from any device. Use of alt tags for image readers Use of Skip Navigation link to bypass complex menus. Use of breadcrumbs to signpost site pages.

5 (e) Here are two sample pages from the EveryNews website. The two web pages above use different types of navigation. Draw a diagram for each page to represent the navigation structure used The following HTML is used to create a web page. A (a) From the HTML above, identify an internal hyperlink and an external hyperlink. 2 Internal: player/hiscore-halo.html OR player/hiscore-gw.html External: OR

6 (b) Draw a diagram to illustrate the navigation structure used in the web page above. 1 (c) Describe a test that should have taken place when this web page was being developed. 1 Check navigation: checking each of the web links points to the required destination Check screen matches design ensuing correct elements on the page, layout is correct and spelling/presentation is accurate (d) The following web page code has been created to ensure accessibility. (i) Give two examples, from the code above, which increase the accessibility of the web page. 2 <a href="#maincontent">skip navigation</a> alt="gamezone Logo" You are at: (and navigational links) (ii) For each example given in (i) above, explain why it makes the page more accessible. 2 Use of Skip Navigation to support screen readers jumping to main content. Use of alt tag to provide screen read text relating to image Use of breadcrumbs (you are at) to aid navigation accessibility

7 16 An app is being developed for students to use to revise for their examinations. The app will show example questions, worked answers, a study planner and the location of friends with the app who are studying the same subjects. A (a) The icons used in the app are stored using a standard file format. (i) State a standard file format suitable for storing these images. 1 JPEG or PNG or BMP or GIF (ii) Explain why the file size of an icon will be smaller if the colour depth is reduced. 2 The colour depth requires a certain number of bits to store the colour value of each pixel in the image Reducing the colour depth normally reduces the number of bits required to store each pixel and therefore reduces the number of bits in the whole file (b) Here is an example of data from the online database that stores data about users and their locations. (i) This data is shown in a flat-file database. Describe two advantages of storing the same data in linked tables. 2 DELETION ANOMALY Will be able to remove the repeating values for users (reducing the storage requirements and speed of access). INSERTION ANOMALY Will be able to store users without them having any location data available. AMENDMENT ANOMALY Will ensure that multiple changes are not required for the same data

8 (ii) Two linked tables are created USER and LOCATION. Identify the fields that would be in each table. 2 USER UserID, First Name, Last Name, (LogID to link) LOCATION Time Logged, Latitude, Longitude, LogID, (OR UserID to link) 1 mark for correct fields, 1 mark for appropriate linking field (iii) Identify a suitable primary key for each table. 2 USER UserID LOCATION LogID (iv) Explain the purpose of a foreign key. 1 The foreign key is used to link (rows with the primary key in other) tables (c) State the type of field required to store the Time Logged data. 1 Date/Time (d) Name and describe a type of validation that could be applied to the field Last Name. 2 Presence check ensures that a name is entered Length check ensures that the name entered is an appropriate length (note Range check would not be suitable here) 17 A programming language has several built in functions. B move(n) n = distance moved in squares (leaving a line) turn(d) d = degrees turned (positive means clockwise) The following program is created to move an item X on the screen. The output of the program and associated notes are shown below. (a) Using the same initial direction, draw the motion path and indicate the end position of an object X which is moved using this program. 3

9 (b) The program is translated using an interpreter. (i) Describe how an interpreter translates the program code. 2 Each line of source code is translated as soon as it is entered Loop constructs have to be translated multiple times as the initial translated code is not kept and so it needs to be translated for each repetition of the loop. (ii) State the name given to the translated binary instructions. 1 Machine code (c) The following command is used in another program. move(4.25) Describe how the number 4.25 would be stored by a computer system. 2 Stored as a real number using floating point representation Where the number is stored as a mantissa and an exponent

10 18 As part of their preparation for their Duke of Edinburgh Silver expedition, S4 pupils at Kinross High School plan to walk a minimum number of miles each week. Their training efforts will be recorded in a computer program. SQA The design for the program is shown below. Line 1. Line 2. Line 3. Line 4. Line 5. Line 6. Line 7. Line 8. Line 9. Line 10. Line 11. Line 12. Line 13. Line 14. Line 15. Line 16. RECEIVE ryantotal FROM file RECEIVE sophietotal FROM file RECEIVE jamestotal FROM file RECEIVE gemmatotal FROM file REPEAT RECEIVE name FROM keyboard RECEIVE distance FROM keyboard IF name = Ryan THEN SET ryantotal = ryantotal + distance IF name = Sophie THEN SET sophietotal = sophietotal + distance IF name = James THEN SET jamestotal = jamestotal + distance IF name = Gemma THEN SET gemmatotal = gemmatotal + distance UNTIL name = exit SEND[ The distance walked by Ryan is & ryantotal] TO DISPLAY SEND[ The distance walked by Sophie is & sophietotal] TO DISPLAY SEND[ The distance walked by James is & jamestotal] TO DISPLAY SEND[ The distance walked by Gemma is & gemmatotal] TO DISPLAY (a) (i) State the type of loop shown in the above design. 1 Conditional (ii) What event causes the program to continue from line 12 on to line 13? 1 The word exit is entered when the user is asked for a name OR when the variable name stores the value exit (b) The current values for the distances walked by each pupil so far are shown below: ryantotal = 15 sophietotal = 12 jamestotal = 9 gemmatotal = 15 These values are stored in the file used in lines 1 to 4. The latest distances walked have now to be added. Show the output from the program when the program is run with the following data: Name distance Ryan 3 Sophie 5 James 6 Gemma 2 exit 4 The distance walked by Ryan is 18 The distance walked by Sophie is 17 The distance walked by James is 15 The distance walked by Gemma is 17 Note: 1 mark for 4 lines of output, 1 mark for correct order, 1 mark for showing concatenation, 1 mark for adding values

11 (c) Line 7 is expanded to ensure that only distances greater than 0 and less than 10 miles can be entered. REPEAT RECEIVE distance FROM keyboard IF distance <= 0 AND distance >= 10 THEN SEND [ Incorrect distance entered ] TO DISPLAY UNTIL distance > 0 AND distance < 10 (i) State the logic error that has been made in the above pseudocode. 1 IF statement should be OR not AND (ii) What effect will this have on the program if a distance of 15 is entered? 1 The error message will not be displayed (d) When the program is run, gemma is entered instead of Gemma. (i) What effect will this have on the program output? 1 The distance entered for Gemma will not be added to the total (ii) What function could be used to prevent this happening? 1 UCASE or LCASE 19 Dino has been asked to create a program to calculate the profit for his school s Young Enterprise group. The program will store the costs involved in producing and selling 100 hand-painted mugs. SQA The following calculations will be used: manufacturing cost = (cost of plain mug x 100) + cost of paint profit = (selling price x 100) manufacturing cost (a) How many variables will Dino need in his program? 1 Five (b) Using a programming language of your choice, write a program to input the required data then calculate and display the profit. In VisualBasic DIM manufacturingcost as single DIM costofplainmug as single DIM costofpaint as single DIM sellingprice as single DIM profit as single 1 mark for correct variables 1 mark for correct data type 5 costofplainmug = InputBox(Please enter cost of mug ) costofpaint = InputBox(Please enter cost of paint ) sellingprice = InputBox(Please enter sellingprice ) 1 mark for inputs

12 manufacturingcost = (costofplainmug * 100) + costofpaint profit = (sellingprice * 100) manufacturingcost 1 mark for correct calculations msgbox( The profit made is & profit) 1 mark for output using concatenation (c) Dino adapts the program to make sure that the cost of the plain mug has to be between 0.50 and Complete the code below to show how this would be implemented. REPEAT IF cost_of_plain_mug < 0.5 OR(1) cost_of_plain_mug > 2.5(1) THEN SEND [ Incorrect price entered ] ENDIF UNTIL cost_of_plain_mug > = 0.5(1) AND cost_of_plain_mug =< 2.5(1) (d) Complete the table below giving four examples of test data and identifying the type of testing 3 Test data (cost_of_plain_mug) Type of Testing 0.50 extreme 1.55 normal 2.50 extreme 3.99 exceptional (e) The school s Young Enterprise group have created a logo. It is stored as a true colour graphic with a resolution of 300 x 400 pixels. Calculate the storage requirements for this graphic. 4 No of pixels = 300 x 400 = 120,000 (1) No of bits per pixel = 24 (true colour) Total no of bits = 24 x 120,000 = (1) 2,880,000/8 = 360,000 bytes (1) 360,000/1024 = KB (1) 20 A programming language provides the following built-in functions. A swap(pos1, pos2, mystring) echo(mystring) Swap the character at position pos1 with the character at position pos2 in a string of text mystring. Write the string mystring to the display.

13 These can be used by the programmer to manipulate strings of text. An example program, with notes on the execution, are shown below. The first character in a string is always position 1. SET mystring TO Passphrase mystring = Passphrase SET val TO 1 val is 1 WHILE val < 3 SET mystring TO swap(val, val+3, mystring) SET val TO val + 1 END WHILE echo(mystring) The following two passes occur, while val is less than 3. val=1, mystring = saspphrase val=2, mystring = spspahrase Output is spspahrase (a) State the output that would be created by the following program. Show what happens with each pass. SET newstring TO computing SET counter to 3 WHILE counter > 0 SET newstring to swap(counter, counter + 2, newstring) SET counter TO counter 1 END WHILE echo(newstring) The following three passes are applied to the string computing Pass 1: counter = 3 swap(3,5, computing ) Result: coupmting (1 mark) Pass 2: counter = 2 swap(2,4, coupmting ) Result: cpuomting (1 mark) Pass 3: counter = 1 swap(1,3, cpuomting ) Result: upcomting Output is upcomting (1 mark) 3 (b) State the type of loop shown in the program. Justify your answer. 2 The loop is a conditional loop (1 mark) because it will continue while the condition (counter > 0) is TRUE (1 mark)