AQA A-level COMPUTER SCIENCE 7517/2 Paper 2 Version: 1.0 Final *JUN* IB/G/Jun23/E7 7517/2QUESTION PAPER & MARKING SCHEMEJune 2023

Examiners are required to assign each of the candidates’ responses to the most appropriate level according to its overall quality, then allocate a single mark within the level. When deciding upon a mark in a level examiners should bear in mind the relative weightings of the assessment objectives. eg In the following questions, the marks available are as follows: Qu Pt Marking guidance Total marks 01 1 Award if correct final answer is shown: 16 // 24 If final answer is not given then award if correct calculation is shown:  400  1000  8   1000  800  2  If final answer is not correct or overall calculation is not clear then award one for each of the points listed below: ⦁ multiplying 400 by 1000 // 400 000 shown in working; ⦁ dividing 3 200 000 or 400 000 or 8000 or 3200 or 400 or 8 by a number; ⦁ multiplying 1000 by 800 // 800 000 shown in working; ⦁ multiplying by 8 to convert from bytes to bits; ⦁ colour depth calculated as 4; ⦁ showing 2x as the last stage of the working, where x is the value calculated so far; 3 Qu Pt Marking guidance Total marks 01 2 Bitmap images store the colour of each pixel // vector graphics do not need to store the colour of each pixel; A. data about pixel instead of colour, but R. just storing pixels The image contains 800 000 pixels // images can contain lots of pixels; Vector graphics store information about / properties of the objects that an image is composed of; A. “shapes” for “object” R. “equations” for “object” R. “instructions” for “object” unless clear that instructions are descriptions of objects A. examples of properties/information instead of the actual words, if there are at least two valid examples NE. vector graphics are composed of objects without reference to properties/information It takes only a small amount of memory to store the properties of an object; (Large) images can be composed of relatively few objects // there will be fewer objects than there would be pixels // a single object might be equivalent to many pixels; Max 3 3 Qu Pt Marking guidance Total marks 01 3 All marks AO1 (understanding) Individual objects / components / parts of the image can be manipulated / edited / duplicated / copied independently; NE. images are easy to edit The image / individual objects / components / parts of the image can be enlarged / scaled without loss of quality / without becoming pixelated // vector graphics are resolution independent; A. zoomed in” for enlarged NE. easy to scale If an object / component is deleted, the software knows what is behind it // no “hole” is left in the image; R. faster transmission times (as a direct consequence of fewer bytes, given in question) Max 2 2 Qu Pt Marking guidance Total marks 02 What it is Processing is carried out // applications/programs are executed on an application server (A. server); NE. Resources are stored on the server Why selected Clients are cheaper to purchase // clients can have lower hardware specification; NE. cheaper without further explanation Less configuration of clients is necessary // easier to configure/add a new client // easier to replace a client; Simpler installation/updating of software (as only done on server); R. if implication that software is on client Impossible to install unauthorised software on workstations // more secure as fewer settings can be changed; Workstations consume less electricity/power; Licensing can be cheaper (as licence per active user not per client); Longer MTBF for workstations // workstations do not fail/break as often // workstations need less maintenance; 3 Qu Pt Marking guidance Total marks 03 1 Bit rate is double / twice baud rate // baud rate is half bit rate; A. “It” is double A. 2:1 1 Qu Pt Marking guidance Total marks 03 2 They are (directly) proportional // the greater the bandwidth, the higher the bit rate; A. as bit rate increases so does bandwidth as BOD NE. bandwidth constrains bit rate 1 Qu Pt Marking guidance Total marks 03 3 Serial sends one bit at a time / after each other whereas parallel sends multiple bits simultaneously/at same time; R. bytes, values, packets, data for bits Serial uses a single wire / cable / path / line whereas parallel uses several / multiple wires / cables / paths / lines; NE. answers that refer to multiple channels 2 INPUTS OUTPUTS X2 X1 X0 Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 1 1 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 1 0 1 0 0 0 0 0 1 0 0 1 1 0 0 0 0 0 0 0 1 0 1 1 1 0 0 0 0 0 0 0 1 Qu Pt Marking guidance Total marks 04 1 Q1 X 2 . X1. X 0 ; A. a logically equivalent expression 1 Qu Pt Marking guidance Total marks 04 2 ⦁ 1 row completed correctly OR ⦁ : 4 rows completed correctly : 8 rows completed correctly 3 Qu Pt Marking guidance Total marks 04 3 : Output Qn is 1 / on / activated when the binary pattern input is the value n A. n for Qn A. relationship between n and output Qn described by example eg if the value of the inputs is 0 then output 0 is on, if the value of the inputs is 1 output 1 is on, and so on. A. it is a (3-bit) binary decoder OR 1 mark: One / a different output is 1 / on / activated for each different input pattern // it converts a binary input to a decimal output 2 Qu Pt Marking guidance Total marks 04 4 Q0; NE. 0 1 Qu Pt Marking guidance Total marks 05 1 ) B; (FacilityID, BookingDate, EndTime) R. if more than one lozenge shaded 1 Qu Pt Marking guidance Total marks 05 2 The design is not normalised // there is (unnecessary) data duplication // there is data redundancy // inconsistent data could occur // (one of the) attributes are determined by attributes that are not (part of) the primary key; If a customer made more than one booking then their details would need to be entered more than once / each time // there would be redundancy in relation to the customer data // customer data could be stored multiple times; If customer details were entered more than once they could be inconsistent // there could be inconsistency in the customer data // updates may need to be made to multiple records if a customer’s details changed; A. updates to customer details would be harder to perform as BOD Deleting all of the bookings that a customer made would also delete the data about the customer; It would not be possible to store details about a customer before they had made a booking; It would be harder to identify all the bookings for one customer (as they did not have a unique identifier) // it may be impossible (A. difficult) to distinguish between two customers with the same name (if they did not have an email address); Notes: ⦁ For all mark points (other than the first) it must be stated that it is the customer data that is the issue to award the mark. ⦁ Accept points stated the other way around, ie as advantages of the new design instead of reasons to reject the original design. Max 2 2 Qu Pt Marking guidance Total marks 05 3 FacilityID INT PRIMARY KEY, // FacilityID INT, PRIMARY KEY(FacilityID), Description VARCHAR(100), MaxPeople INT, PricePerHour SMALLMONEY : FacilityID, with sensible data type and identified as primary key. : two fields other than the primary key have sensible data types and lengths (if given). : fully correct definition, with syntactically correct SQL including commas separating each line of code. A. any sensible types. Lengths do not need to be specified. I. brackets at the start / end of the code Valid alternative SQL types are: ⦁ Alternative types for FacilityID and MaxPeople: tinyint, smallint, mediumint, integer, number, byte. ⦁ Alternative types for Description: char, nchar, nvarchar, ntext, longvarchar, varchar2, nvarchar2, text, tinytext, mediumtext, longtext, string. ⦁ Alternative types for PricePerHour: money, float, real, decimal, double, numeric, currency. R. integer only types. 3 Qu Pt Marking guidance Total marks 05 4 Mark Scheme for correctly analysing the data model and identifying the tables that data needs to be extracted from (FacilityForSport, Booking) and the fields that need to be extracted (FacilityID, StartTime, EndTime), and including these and no other tables or fields in the query for correctly identifying the condition to select facilities suitable for the correct sport: Sport = "Basketball" or correctly identifying the condition to select bookings on the required date: BookingDate = "15/06/2021" for correctly identifying the condition to link the two tables: Booking. FacilityID = FacilityForSport.FacilityID for at least one condition that would identify some overlapping bookings and no bookings that don’t overlap, or 2 marks for conditions that would identify all overlapping bookings and no bookings that don’t overlap. Example conditions (not the only ones) that would identify all overlapping bookings: Example set of conditions 1 StartTime = "14:15" AND EndTime = "16:15" (existing booking starts before and ends after new booking) StartTime = "14:15" AND StartTime = "16:15" (existing booking starts during new booking) EndTime = "14:15" AND EndTime = "16:15" (existing booking ends during new booking) Example set of conditions 2 StartTime = "16:15" AND EndTime = "14:15" (existing booking starts before or at the same time as the end of new booking and ends after or at the same time as the start of new booking) Note: Award a maximum of 2 of the 3 marks for the correct conditions if they are not joined by the correct logical operators. Note: The AO2 marks for analysing the data model should be awarded regardless of whether correct SQL syntax is used or not as they are for data modelling, not syntactically correct SQL programming A. mark(s) can be awarded for the correct logical conditions even if the required tables are not identified as being used by the query A. instead of = and instead of = 7 ⦁ mark for fully correct SQL in two of the three clauses (SELECT, FROM, WHERE) OR ⦁ marks for fully correct SQL in all three clauses (SELECT, FROM, WHERE) Notes: ⦁ For the SELECT clause to count as correct SQL it must have the correct field names in it and no others. ⦁ For the FROM clause to count as correct SQL it must have the correct table names in it. Other, unnecessary tables can also be included so long as they are correctly linked into the query by conditions so would not break it. ⦁ For the WHERE clause to count as correct SQL it must include at least one valid condition, but does not have to include them all. A. instead of FacilityForSport.FacilityID accept Booking.FacilityID or just FacilityID in the SELECT clause for non- nested queries. For a nested query accept X.FacilityID where X is the alias of the relation produced by the nested query eg BookingsAtTime in example 3. A. table names before fieldnames separated by a full stop. A. use of Alias/AS command eg FROM Booking AS B then use of B as the table name and note that command AS is not required eg FROM Booking B. A. INNER JOIN written as one word ie INNERJOIN. A. insertion of spaces into fieldnames. I. unnecessary brackets so long as they would not stop the query working. A. use of any type of quotation marks, hashes or no delimiters around dates and times. A. month in date as 6 instead of 06 A. instead of = and instead of = DPT. for unnecessary punctuation – allow one semicolon at the very end of the statement, but not at the end of each clause. DPT. for fieldname before table name. Overall Max 6 if solution does not work fully Example Solutions Example 1 – All conditions in WHERE clause SELECT FacilityForSport.FacilityID, StartTime, EndTime FROM FacilityForSport, Booking WHERE Sport = "Basketball" AND Booking.FacilityID = FacilityForSport.FacilityID AND BookingDate = "15/06/2021" AND ( StartTime = "14:15" AND EndTime = "16:15" OR StartTime = "14:15" AND StartTime = "16:15" OR EndTime = "14:15" AND EndTime = "16:15" ) Example 2 – Use of INNER JOIN SELECT FacilityForSport.FacilityID, StartTime, EndTime FROM FacilityForSport INNER JOIN Booking ON Booking.FacilityID = FacilityForSport.FacilityID WHERE Sport = "Basketball" AND BookingDate = "15/06/2021" AND ( StartTime = "14:15" AND EndTime = "16:15" OR StartTime = "14:15" AND StartTime = "16:15" OR EndTime = "14:15" AND EndTime = "16:15" ) Example 3 – A Nested Solution SELECT FacilityForSport.FacilityID, StartTime, EndTime FROM ( SELECT FacilityID, StartTime, EndTime FROM Booking WHERE BookingDate = "15/06/2021" AND ( StartTime = "14:15" AND EndTime = "16:15" OR StartTime = "14:15" AND StartTime = "16:15" OR EndTime = "14:15" AND EndTime = "16:15" ) ) AS BookingsAtTime INNER JOIN FacilityForSport ON BookingsAtTime.FacilityID = FacilityForSport.FacilityID WHERE Sport = "Basketball" Refer nested solutions to team leaders for marking R0 R1 R2 R3 R4 100010 (34) 110 (6) 0 (0) 1 (1) 1 1100 (12) 10 (2) 2 11000 (24) 100 (4) 110000 (48) 1000 (8) 11000 (24) 100 (4) 3 100 (4) 1010 (10) 4 0 (0) 5 1100 (12) 10 (2) 0 (0) 110 (6) 1 (1) 101 (5) 100 (4) 6 1 (1) 0 (0) Qu Pt Marking guidance Total marks 06 1 : Correct initial values loaded into R0 and R3 – Area 1 : Logical shifting left of register values in loop – Area 2 : Exiting loop and shifting right – Area 3 : First addition and subtraction on R0 and R3 – Area 4 : Addition and subtraction loop – Area 5 : Correct final values in registers R0 and R1 – Area 6 Award marks for the correct values in the indicated areas. The values do not need to be in the exact cells shown for marks to be awarded, but must be in the correct sequence in the column they are in. Award marks for values written in either decimal or binary. If a binary and decimal value are written in one cell and one is correct but the other incorrect then treat the cell as being correct if any incorrect values in table. 6 Qu Pt Marking guidance Total marks 06 2 All marks AO2 (analyse) Performs (integer) division // outputs the quotient after performing a division // outputs how many times one number (R2) goes into another (R1) // R0 is the quotient; Outputs the remainder / what is left over after performing (integer) division // R1 is the remainder; 2 Qu Pt Marking guidance Total marks 07 1 All marks AO1 (understanding) Why laser is suitable (Low cost per printed page // toner is cheaper (per page) than ink; Prints many pages per minute // high speed; Options to install a (greater) variety of paper trays // (greater) variety of paper handling options; Toner will not dry out; A. toner does not expire as quickly as ink; High resolution output; Why having a wireless adapter is suitable ( Easy to share printer between many devices; Can connect / print directly from computers / laptops with WiFi // no need to install a network / cabling / wireless router to facilitate wireless / network / remote printing; Printer can be managed remotely; WiFi should be fast enough for likely number of users / documents (as small office); WiFi should have sufficient range for devices to connect (as small office); 3 Qu Pt Marking guidance Total marks 07 2 All marks AO1 (understanding) Level Description 3 A comprehensive description of how a laser printer works, which shows an excellent level of understanding, covering almost all of the indicative content below. 2 A sound description of how a laser printer works, which shows a good level of understanding. The key parts of the indicative content are covered but there are gaps in the description. 1 Some relevant points are made, but overall the description conveys only a limited understanding, either because only a very small number of points are made or the points made are not drawn together to form an accurate description. Guidance – Indicative Content ⦁ Bitmap of image built in memory from page description. ⦁ (Negative) charge applied to (photosensitive) drum. ⦁ Laser beam directed at drum. R. laser directed at paper. ⦁ Mirror is used to direct laser beam. ⦁ Where laser strikes drum charge is neutralised / reversed / cancelled / discharged. ⦁ (Negative) charge applied to toner. ⦁ Toner sticks to drum based on charge // where the laser struck. ⦁ Paper passed over drum and toner transfers to it. ⦁ Positively charged transfer roller assists transfer of toner from drum to paper. ⦁ charge applied to paper assists with transfer. ⦁ Heater fuses toner onto paper. ⦁ For colour printing four different colour toners // four drums are required. 6 Qu Pt Marking guidance Total marks 08 All marks AO2 (apply) : Both 18 and -72 represented correctly in two’s complement: ⦁ 18: ⦁ -72: : Correct answer in binary: 2 Qu Pt Marking guidance Total marks 09 All marks AO1 (understanding) Level Description Mark Range 4 A line of reasoning has been followed to produce a 10–12 coherent, relevant, substantiated and logically structured response. The response covers all three areas indicated in the guidance below and in at least two of these areas there is sufficient detail to show that the student has a good level of understanding. To reach the top of this mark range, a good level of understanding must be shown of all three areas. 3 A line of reasoning has been followed to produce a 7–9 coherent, relevant, substantiated and logically structured response which shows a good level of understanding of two areas indicated in the guidance below or a good level of understanding of one area and a reasonable level of understanding of the other two areas. To reach the top of this mark range, a good level of understanding must be shown of two areas. 2 A limited attempt has been made to follow a line of 4–6 reasoning and the response has a mostly logical structure. A good level of understanding has been shown of at least one area or some understanding has been shown of all three areas. 1 A few relevant points have been made but there is no 1–3 evidence that a line of reasoning has been followed. The points may only relate to one or two of the areas from the guidance. There is insufficient evidence of a good understanding of any of the three areas. Guidance – Indicative Content Area 1: What Big Data is Overarching description: Data that can’t be processed or analysed using traditional processes or tools. 12 Characteristic Expansions / Examples Variety of different forms of information // data may lack structure Cannot be represented in a table // by a relational database Email messages Videos Images Web site contents Facial recognition There is a lot / high volume of data (to process as one dataset) // data will not fit on one server Hundreds of terabytes Large medical datasets for diagnosis Gene sequencing Predicting disease outbreaks Results of large-scale scientific experiments The data is generated / received / must be processed at high velocity / very quickly Thousands of items to process per second. Data must be processed as it is received – it cannot be batched and processed later Card payment fraud detection Recommendations systems Good level of understanding = Either all three characteristics covered or two characteristics and the overarching description. Some examples or expansions covered. Area 2: Challenges and How Overcome Challenges: ⦁ Data cannot be stored on one server / computer. ⦁ Not possible to process data quickly enough with one computer. ⦁ Data cannot be represented in a table // by a relational database. ⦁ Some forms of data / unstructured data are difficult to analyse. How overcome: ⦁ Distributed database systems // distributed file systems // blocks of individual files distributed across multiple servers. ⦁ Use of functional programming. ⦁ (Massively) parallelising the execution of programs. ⦁ MapReduce // input split into parts then mapper executed on each part then all results combined by reducer(s) // function-to-data model. ⦁ Functional programming makes it easier to write distributable code // determine which parts of code can be run independently. ⦁ Functional programming makes it easier to write correct code // example features of functional programming that facilitate writing correct code ⦁ Use of many thousands of commodity servers. ⦁ Use of servers with multiple CPUs / cores / drives. ⦁ Machine learning can identify patterns / the value in the data // use of predictive data models. ⦁ Use of languages such as XML or JSON to describe semi-structured data. ⦁ Use of fact-based model can manage bigger data sets better than relational model. Good level of understanding = A range of challenges and how to overcome them are discussed. Area 3: Ethical and Legal Issues ⦁ How can data be kept securely? ⦁ Who should have access to what data? ⦁ Will people know what data is being stored about them? ⦁ Where should / will the data be stored // concerns relating to data being stored in other countries. ⦁ What rights do people have in relation to data stored about them? ⦁ Example laws (allow two examples): Computer Misuse Act, General Data Protection Regulations / GDPR / Data Protection Act, Regulation of Investigatory Powers Act / RIPA. ⦁ Who owns data about individuals? Good level of understanding = A range of issues described Qu Pt Marking guidance Total marks 10 1 All marks AO2 (analyse) 1 mark per correct letter on a row. If a letter is used more than once then a mark should only be awarded (if merited) the first time the letter is used. Subsequent reuse of the same letter should not be credited even if the second/third use of the letter is in the correct position. 3 Value description Correct letter (A-D) A negative value that is valid in the representation. A; The largest positive value that can be represented in the system. D; A value that is not valid in the representation because it is not normalised. C; Qu Pt Marking guidance Total marks 10 2 All marks AO2 (apply) Award for correct answer: 52 If answer is incorrect then award for either: ⦁ showing correct value of both mantissa and exponent in decimal (Mantissa = 0.8125 // 13/16 Exponent = 6) ⦁ showing binary point shifted 6 places to right in binary number ⦁ indicating that final answer has been calculated using answer = mantissa x 2exponent and used either the correct mantissa, the correct exponent, or both in this calculation. 2 Qu Pt Marking guidance Total marks 10 3 Mark is AO2 (apply) 0.3 // 105 - 104.7 // | 104.7 - 105 |; A. award BOD mark if correct method has been shown ie 105 - 104.7 but candidate has then made an error performing the subtraction operation R. -0.3 unless the accept point above also applies 1 Qu Pt Marking guidance Total marks 10 4 0.29(%); A. 0.0029 // 0.3 ÷ 104.7 A. follow-through of incorrect answer to question part 10.3 A. award BOD mark if correct method has been shown but candidate has then made an error performing the division operation 1 Qu Pt Marking guidance Total marks 10 5 The effect / impact of an error depends on its size relative to the number that is / should be represented // a particular (absolute) error is more significant the smaller the number that is / should be represented // a particular (absolute) error is less significant the bigger the number that is / should be represented; NE. relative error shows the significance/importance of error 1 Qu Pt Marking guidance Total marks 11 1 3 per valid IP address The Router 1 port 192.168.x.y labelled A where: ⦁ x is in range 192 to 207 ⦁ y is in range 0 to 255 R. 192.168.192.0 R. 192.168.207.255 The Router 1 port 192.168.x.y labelled B where: ⦁ x is in range 64 to 79 ⦁ y is in range 0 to 255 R. 192.168.64.0 R. 192.168.79.255 The computer 192.168.x.y labelled C where: ⦁ x is in range 64 to 79 ⦁ y is in range 0 to 255 R. 192.168.64.0 R. 192.168.79.255 R. same response as for part B Qu Pt Marking guidance Total marks 11 2 C; (255.255.240.0) R. more than one lozenge shaded 1 Qu Pt Marking guidance Total marks 11 3 There are not enough (unique) addresses in IPv4 // IPv4 addresses are running out // to provide more addresses; Eliminate need for NAT / network address translation // facilitates true end-to-end connectivity; Simplified / more efficient routing is possible; Improved facilities for multicasting; Automatic configuration possible without DHCP; Allows bigger packet sizes; Devices can move / roam between location and keep the same IP address; Improved support for prioritising traffic by type; Max 1 1 Qu Pt Marking guidance Total marks 11 4 Star; A. physical star, star topology, star network 1 Qu Pt Marking guidance Total marks 11 5 3 A detailed, coherent, description of CSMA/CA that includes the use of RTS / CTS and that conveys good understanding of how the protocol works. Whilst there may be some omissions from the description it contains no misunderstandings. 2 An adequate description of CSMA/CA, including at least three points from the list below. The description is logically organised so that it makes sense when read as a whole and therefore demonstrates a reasonable understanding of how the protocol works. The description may or may not include the use of RTS / CTS. 1 A small number of points relevant to of CSMA/CA have been recalled (in this case award one mark per point, up to a maximum of two from lists below). However, the structure of the response, or lack of it, demonstrates only a very limited understanding, if any, of the protocol used. Indicative Content ⦁ Computer with data to send monitors / listens for (data signal). ⦁ If (data) signal present / another transmission in progress then continue to wait. ⦁ When no (data) signal present computer sends a Request to Send / RTS. A. if no valid points made about RTS / CTS in response then accept ‘when no data signal is present computer starts to transmit data’, but since no marks awarded for RTS / CTS then marks are limited to max Level 2. ⦁ Two computers could start transmitting simultaneously if they both detect there is no data signal. ⦁ Receiver / WAP responds (to RTS) with a Clear to Send / CTS signal. A. router ⦁ RTS / CTS signal blocks any other transmissions from nodes in range (for a specified time). ⦁ If / when CTS received then start to transmit. A. by implication as BOD if the student states that the computer will begin to transmit after the receiver sends the CTS. ⦁ If CTS not received continue to wait (until transmission ends). ⦁ Receiver sends acknowledgement / ACK after (all) data received ⦁ After transmitting (the transmitter) waits to receive acknowledgement packet (to confirm data received and not corrupted). ⦁ If no acknowledgement / ACK received (within reasonable time period) then: ⦁ wait a time period. ⦁ then listen again / retransmit. ⦁ The acknowledgement / ACK also notifies other computers that they can transmit again // after the time specified in the CTS passes, other nodes can transmit. ⦁ Waiting periods are (often) random. A. an example waiting period that is random. ⦁ Collisions cannot be detected by transmitter. 6 Qu Pt Marking guidance Total marks 12 Music represented as sequence of MIDI (event) messages; A. music represented as sequence of instructions A. “events” for “event messages” R. music represented as sequence of notes for an example of data that might be contained in a message: ⦁ Channel; ⦁ Note on / note off; ⦁ Pitch / frequency / note number; ⦁ Volume / loudness; ⦁ Velocity; ⦁ Key pressure / aftertouch; ⦁ Duration / length; ⦁ Timbre; ⦁ Instrument; ⦁ Pedal effects; ⦁ Pitch bend; ⦁ Note envelope; MIDI messages are usually two or three bytes long; First byte of each MIDI message is a status byte (others are data bytes); Bit rate is 31,250 bits per second; MSB value of 1 indicates status byte, 0 indicates data bytes; Status bytes are divided into a command and a channel number (4 bits for each); Sixteen channels are supported; 2 Qu Pt Marking guidance Total marks 13 1 ) Application Software: Performs user-oriented tasks // performs tasks that a user would still want to perform if they did not have a computer; NE. examples of tasks System Software: Software used in the management of a computer system; A. software that is used to run a computer Layer(s) of software that abstract the user from how the computer works; A. software that hides complexity of hardware from user A. software that provides a virtual machine 2 Qu Pt Marking guidance Total marks 13 2 Description ((Software that) performs a non-core / ancillary / specific management function for a computer; A. (software that) performs a task that helps manage / configure / maintain a computer A. (software that) manages a computer system but is not essential NE. (software that) manages a computer Example (Award a mark for a statement of any reasonable example, such as virus checker, disk defragmenter, backup, compression, encryption software etc; R. examples that relate to core functions of the operating system R. examples that are application software or if the response includes multiple examples, one of which is application software 2 Qu Pt Marking guidance Total marks 14 1 B; (The computer can only be used with one program) R. more than one lozenge shaded 1 Qu Pt Marking guidance Total marks 14 2 To marshal / control operation of fetch-execute cycle; Controls fetching / loading / storing operations; NE. fetches instructions Determines the type of an instruction; A. decodes instructions To execute (some) instructions; To synchronise operation of processor; To send control signals / commands to other components; To control the transfer of data between registers; To handle interrupts; 3 Qu Pt Marking guidance Total marks