Computer studies P2 HG 2013 Memo hlayiso.com

Downloaded from hlayiso.com basic education Department: Basic Education REPUBLIC OF SOUTH AFRICA SENIOR CERTIFICATE EXAMINATION MARKS: 200 Copyright reserved Please turn over

Downloaded from hlayiso.com Computer Studies/HG/P2 2 DBE/2013 SCE —- Memorandum QUESTION 1: MULTIPLE-CHOICE QUESTIONS i DD) 12 D 13 A 14 C 15 C 16° #C 1.7 B 18 B 19 A 1.10 C [10] QUESTION 2: BOOLEAN ALGEBRA 2.1 \ 1 1 1 1 1 1 1 F(A,B,C,D) = C'D' ¥+ ¥ B'CY (YY grouping , Y“v for answer) (-1 if extra terms) (5) 2.2 2.2.1 F(X,Y,Z) =m,+m3+Me +mM7 vv (2) 2.2.2 F(X,Y,Z) = X'Y'Z + X'YZ + XYZ'+XYZ VV = X'Z(Y'+ Y) V+ XY(Z+Z)V = X'Z (1) + XY¥(1) ¥ = X'Z+XY Vv (6) 2.3 Circuit for the sum of a half-adder: (3) [16] Copyright reserved Please turn over

Downloaded from hlayiso.com Computer Studies/HG/P2 3 DBE/2013 SCE — Memorandum QUESTION 3: COMPUTER ARCHITECTURE 3.1 3.1.1 Cache memory is high speed memory Vv that is used to store instructions that are likely to be used next V in the running of a program 3.1.2 on motherboard VY, on CPU chip ¥ 3.1.3 very expensive Vor very big of RAM chip 3.2 3.2.1 address bus VY, control bus W 3.2.2 More data can be transferred V in one clock cycle so the computer processes information faster ¥ 3.2.3 to store temporary data V for data inside CPU 3.3 3.3.1 clock multiplication — pulses of system clock are multiplied by a number” in order for the system clock to work at the desired speed Y of the component that needs it. 3.3.2 over clocking — change the speed of the system clock v via the BIOS-setting to achieve faster speeds than what the system was designed for. 3.4 smaller CPU, smaller resistors closer together — fit more onto chip, process faster as have shorter distance to send data vv (Any TWO) 3.5 3.5.1 Universal serial bus 3.5.2 Supply power to some devices, many devices can be plugged in to these slots, fast data-transfer rate, high-speed slots vv (Any TWO) 3.6 AGP slot — to plug in graphics card¥ 3.7 Latency Y and seek time V 3.8 64-bit can process twice as many bits as 32-bit “ thus making the computer faster V. Size of registers is 32/64 bits Copyright reserved Please turn over (2) (2) (1) (2) (2) (1) (2) (2) (2) (1) (2) (1) (2) (2)

Downloaded from hlayiso.com Computer Studies/HG/P2 4 DBE/2013 3.9 3.9.1 3.9.2 3.10 3.10.1 3.10.2 3.10.3 3.10.4 Copyright reserved SCE — Memorandum Pipelining — A method of processing whereby the processor reads new instructions “ from the memory Y before the current instruction that is being processed, has been processed ¥ decision making V — use branch prediction to 'guess' which way to gov’ OR Data dependancies — executes instructions out of order OR Pipeline stall — multiple branch prediction, analysis of data flow, looks ahead of program counter to predict next instruction (“any ONE) Hyperthreading — (i) one CPU is treated as if there are 2 CPUs ¥ (ii) — faster speed ¥ multithreading — (i) ability of operating system to execute different parts of a program (threads) simultaneously ¥ (ii) can complete more than one task at a time e.g. typing in word processor and checking spelling in background V Firewire — (i) serial communication link ¥ (ii) for high speed data capturing V— e.g. digital video PCI express- (i) joins internal and external buses ¥ (ii) better technology to cope with faster graphics v, faster hard drives and faster. CPUs — switch is an intelligent device that connects each component together and sends signals only to the intended recipient Please turn over (3) (2) (1) (1) (1) (1) (1) (1) (1) (1) [37]

Downloaded from hlayiso.com Computer Studies/HG/P2 5 DBE/2013 SCE — Memorandum QUESTION 4: SYSTEM SOFTWARE 41 4.1.1 The user interface Vand the kernel ¥ 4.1.2 Minimise turnaround time ¥ Maximise throughput “ Efficient utilisation of resources V 4.2 4.2.1 Software v that allows hand held devices V to operate — operating system is embedded on the ROM chip. OS is permanently built into device 4.2.2 PALM OS, Windows CE, Pocket PC OS, Windows Mobile v (Any correct answer) 4.3 4.3.1 Virtual memory — on the hard drive. 4.3.2 Paging — the system used to move data between the hard drive and RAM - breaks the program into segments Y and moves these between the hard drive and the RAM when necessary Y. Too much paging results in thrashing and the computer slows down or hangs ¥ 4.4 4.41 Buffer — temporary storage space in primary memory Y where items are stored while waiting to be sent to an output device V 4.4.2 Spooler — program vthat places jobs in a queue “and is used when a large amount of data is being sent to a slow output device 45 4.5.1 compiler — translates or compiles the complete source program into machine language ¥ Interpreter — translates and executes a program line by line V 4.5.2 DELPHI, Turbo Pascal, Fortran, VB, C++ v (Any ONE) 4.6 Multitasking — the CPU splits its time “very quickly, between the processes that are running to appear as if more than one program is running simultaneously. ¥ OR The computer shares the CPU time and resources are allocated to the programs according to their specific needs. 4.7 security, database of passwords, users etc, file and print sharing, web server software, network traffic monitoring, firewall vv (Any TWO) Copyright reserved Please turn over (2) (3) (2) (1) (1) (3) (2) (2) (2) (1) (2) (2)

Downloaded from hlayiso.com Computer Studies/HG/P2 6 DBE/2013 48 4.8.1 4.8.2 SCE — Memorandum date and time of creation, size of file, read only, hidden, system vv (Any TWO) Parts of a file are not stored contiguously W. In order to rearrange the parts of a file “and to make the computer faster. QUESTION 5: DATA COMMUNICATION FDDI — Fibre Distributed Data Interface V 5.1 5.1.1 5.1.2 NIC — Network Interface Card W 5.2 5.2.1 TCP/IP ¥ 5.2.2 Messages are dividend and sent in small packets V of different lengths Y with a strict maximum length. Different routes V can be followed thorough the network. Once all packets vY (sent individually) arrive at the destination, they are reassembled V into the original data. 5.3 5.3.1 Passwords must change regularly/after certain period of time, restrict time of access to the system, limit the rights and access to certain files and directories, delete users that no longer work at the company. vv v (Any THREE) 5.3.2 Firewall — Hardware and or software ¥ that is used to stop unauthorised access to or from a private network, by blocking access to a port ¥ 5.4 Can phone and fax or surf the Internet at same time, permanent connection, 3G can have connectivity/range problems vv (Any ONE) 5.5 5.5.1 Ethernet network cards to connect each computer to the network 5.5.2 UTP cables for physical connection — within 100 m 5.5.3 Switch - allows computers to use full bandwidth”, receives data and sends to specific device saving time and improving performanceY 5.6 5.6.1 Can connect through walls and further than infra red 5.6.2 Hands-free car kit Copyright reserved Please turn over (2) (2) [27] (1) (1) (1) (5) (3) @ (2) (1) (1) (2) (1) (1)

Downloaded from hlayiso.com Computer Studies/HG/P2 7 DBE/2013 5.7 5.8 5.9 5.10 SCE — Memorandum 5.7.1 Ethernet Vv _ CSMA/CD — can send whenever you want to ¥ -— aworkstation that wants to send a message, listens for traffic on network before transmitting Vif no traffic, transmission can begin — message is broadcast to all workstations V - must check whether there is a collision, if there was a collision, workstation waits and then tries again V 5.8.1 Satellite — very expensive 5.8.2 Radio and TV, ships at sea v (Any ONE) GPRS -— always connected to the Internet - pay for packets that are sent and received — browse, search and e-mail on the move — use higher rate of data transfer than standard 9.6kbps of telephone lines v v v (Any three) RAID — to protect data from getting lost/scrambled VY. A number of hard disks are needed v. Data is spread over the disks v. QUESTIONG6: SOCIAL IMPLICATIONS 6.1 6.1.1 Keylogging — software that tracks the keys pressed ¥ 6.1.2 Phishing — an e-mail requesting personal info — someone claiming that they are checking your data and request a response W 6.1.3 BYOD — use company Internet access to gather data V 6.2 Encryption — public key is used to encode dataY and a private key is used to decrypt data ¥ 6.3 EULA — (End User License agreement) — what the user can and cannot do when making use of the software “ 6.4 6.4.1 Voice over the Internet protocol “ 6.4.2 Cheap international phone calls — pay for local connection ” Copyright reserved Please turn over (1) (4) (1) (1) (3) (3) [34] (1) (1) (1) (2) (1) (1) (1)

Downloaded from hlayiso.com Computer Studies/HG/P2 8 DBE/2013 SCE — Memorandum 6.5 It takes a long time V and a lot of effort to program good software and these people lose out on royalties VY and money that could be used to improve the software. 6.6 Open Office, Libre Office v (Any ONE) 6.7 pointing stick, helmet with pointer, large roller ball mouse v (Any ONE) 6.8 6.8.1 A card with built-in memory chip that can record, change information ¥ 6.8.2 Taxi cards — safer for passengers cellphone cards — some cards can perform banking transactions electronic purse — safer — don’t have to carry cash, don’t have to qualify for a card, reduces risk of robbery, difficult to duplicate v (Any ONE) 6.9 6.9.1 An office that you can take with you — movable ¥ 6.9.2 Always at the office, always connected, do not spend time with the family v (Any ONE ) QUESTION 7: DELPHI/TURBO PASCAL PROGRAMMING 7.1 Valid — data within the requirements — only 8 to 12 “ Correct — If the person is in Grade 10, then a 10 should be entered and anything else will be incorrect ¥ 7.2 p:=pos(‘writing’,sentence); v deletev (sentence,pv ,7”); OR delete(sentence,6,7); 7.3 7.3.1 7.3.2 Copyright reserved (a) while do VW” (c) _ for...dovY Please turn over (2) (1) (1) (1) (2) (1) (1) [17] (2) (4) (2) (2)

Downloaded from hlayiso.com Computer Studies/HG/P2 9 DBE/2013 SCE — Memorandum 7.4 Program select; Var a, loop,loop2,R : integer; // variable names could be different Begin For loop : = 1 to 6 do ¥ begin R : = random(count) ¥+1V; For loop2:= 1 to count do Y //OR found:= false; while loop2 <=count If prizes[loop2] = R “then winners[loop]:=Prizes[r]; ~ End; End; For loop := 1 to 6 do WriteIn(Winners[loop]); Vv OR // Redoutput.lines.add(Winners[loop]); (8) [18] QUESTION 8: DELPHI/TURBO PASCAL PROGRAMMING 8.1 8.1.1 LETTERS = array[1..6v’,1..8] “ of char v; ( rows, columns, data type) OR LETTERS = array[1..6,1..8] of string[1]; (3) 8.1.2 sum := 0; ¥ for row := 1 to 6 do ¥ for col :=1to8do ¥ If ~¥ LETTERS[row,col] ¥ ='H' “then inc(sum); “ (7) Copyright reserved Please turn over

Downloaded from hlayiso.com Computer Studies/HG/P2 10 DBE/2013 8.2 8.2.1 8.2.2 8.2.3 8.2.4 8.2.5 8.2.6 8.2.7 8.2.8 SCE — Memorandum reference parameter — has a var V in front to return a value to the main program ¥ line : string[80]; /string; count,vowel:integer; newline:string; assign(tf,;c:\STORY.TXT’) OR assignfile(tf,’c:\STORY.TXT )¥Y While not Eof(tf) do ” readin(tf, line);“¥¥ Newline:=" Vv for count : = length(line) V¥ downto ido ¥ v v v v if upcase(line[count]) in [‘A’, ‘E’, ‘I’, ‘O’, ‘U’] then inc(vowel) else newline:= newline ¥’+line[count] “ close(tf) OR closefile(tf);” Sentence:= newline; ¥ Num := vowel; ¥ QUESTION 9: DELPHI/TURBO PASCAL PROGRAMMING 9.1 seek(PofCountry,9); vv read(PofCountry,CountryData); v 9.2 function checking(X “: CountryData) “:Boolean; “ Begin v v v v If (x.points) > 1 then checking :=true else checking :=false; End; TOTAL: Copyright reserved (2) (2) (2) (1) (2) (9) (1) (2) [31] (3) (7) [10] 200