Computer Studies November 1997
Question 1
Digital data are values that changes in discrete steps and can be used for counting.
A user guide or manual that the user can turn to for learning a new procedure or for dealing with a problem that has arisen.
It is a combination of scanner and software which is able to read characters into a computer.
Assembler is a program that converts assembly language into machine code.
Validation is check performed by a computer program to make sure the data inputted is reasonable and valid.
Mailbox is a facility in which electronic mails can be stored until the destination user request delivery of the electronic mails.
Polling is the continuous checking of other devices and programs in a multi-access system to see whether they are still connected or readiness to receive and collect data.
Question 2
A compiler is software that converts the whole of a program written in a high-level language into machine code in one go.
i. High level languages have simple instructions similar to English make high-level languages easy to understand.
ii. Programs written in high-level languages are problem orientated therefore portable on different makes of computer.
i. Operating systems
ii. Programming in low level languages needs little or no translation therefore it is faster and also able to address hardware directly.
iii. Procedures can be kept in the library for use in many other programs.
iv. It is easier to correct errors and easier to understand programs using procedures.
Question 3
i. Pupils can communicate with each other through electronic mails, chat lines or community groups on a wide area network.
ii. Pupils can get access to large quantities of information through a wide area network such as the Internet.
iii. Pupils can get access to specialist teaching or electronic learning through a wide area network.
Portable computers with modems can be used to contact their offices and large databases or expert system to gather information to help them assist their customers.
Question 4
i. Batch processing is when lots of different jobs are stored up and then all processed together at the same time usually at regular periods.
ii. One example is a large businesses payroll system where all their employees’ wages are processed and calculated at the same time every month.
i. In a real time processing, the system is automatically updated when a change is made due to a transaction occurring.
ii. In an airline booking system, when you book a seat on an aeroplane, your details are entered and the seat is booked straight away so no other user of the system can book the same seat.
Question 5
i. B1
ii. G2
iii. B2
iv. =SUM(B2:D2)
v. Highlight cell E2, select the copy command, then highlight cell E3 to E7 and select the paste command.
vi. G2
vii. E4 and G4
Highlight cell B2 to G2, select the format command and set the number to 2 decimal places.
Question 6
|
TITLE (Mr/Mrs/Ms/etc) |
a) |
b) |
c) |
d) |
e) |
f) |
g) |
h) |
i) |
j) |
k) |
l) |
m) |
n) |
o) |
p) |
q) |
|
r) |
s) |
t) |
u) |
v) |
w) |
x) |
y) |
z) |
aa) |
bb) |
cc) |
dd) |
ee) |
ff) |
gg) |
hh) |
|
|
SURNAME |
ii) |
jj) |
kk) |
ll) |
mm) |
nn) |
oo) |
pp) |
qq) |
rr) |
ss) |
tt) |
uu) |
vv) |
ww) |
xx) |
yy) |
|
zz) |
aaa) |
bbb) |
ccc) |
ddd) |
eee) |
fff) |
ggg) |
hhh) |
iii) |
jjj) |
kkk) |
lll) |
mmm) |
nnn) |
ooo) |
ppp) |
|
|
FIRSTNAME |
qqq) |
rrr) |
sss) |
ttt) |
uuu) |
vvv) |
www) |
xxx) |
yyy) |
zzz) |
aaaa) |
bbbb) |
cccc) |
dddd) |
eeee) |
ffff) |
gggg) |
|
hhhh) |
iiii) |
jjjj) |
kkkk) |
llll) |
mmmm) |
nnnn) |
oooo) |
pppp) |
qqqq) |
rrrr) |
ssss) |
tttt) |
uuuu) |
vvvv) |
wwww) |
xxxx) |
|
|
ADDRESS |
yyyy) |
zzzz) |
aaaaa) |
bbbbb) |
ccccc) |
ddddd) |
eeeee) |
fffff) |
ggggg) |
hhhhh) |
iiiii) |
jjjjj) |
kkkkk) |
lllll) |
mmmmm) |
nnnnn) |
ooooo) |
|
ppppp) |
qqqqq) |
rrrrr) |
sssss) |
ttttt) |
uuuuu) |
vvvvv) |
wwwww) |
xxxxx) |
yyyyy) |
zzzzz) |
aaaaaa) |
bbbbbb) |
cccccc) |
dddddd) |
eeeeee) |
ffffff) |
|
|
gggggg) |
hhhhhh) |
iiiiii) |
jjjjjj) |
kkkkkk) |
llllll) |
mmmmmm) |
nnnnnn) |
oooooo) |
pppppp) |
qqqqqq) |
rrrrrr) |
ssssss) |
tttttt) |
uuuuuu) |
vvvvvv) |
wwwwww) |
|
|
xxxxxx) |
yyyyyy) |
zzzzzz) |
aaaaaaa) |
bbbbbbb) |
ccccccc) |
ddddddd) |
eeeeeee) |
fffffff) |
ggggggg) |
hhhhhhh) |
iiiiiii) |
jjjjjjj) |
kkkkkkk) |
lllllll) |
mmmmmmm) |
nnnnnnn) |
|
|
DATE OF BIRTH |
ooooooo) |
ppppppp) |
qqqqqqq) |
rrrrrrr) |
sssssss) |
ttttttt) |
uuuuuuu) |
vvvvvvv) |
wwwwwww) |
xxxxxxx) |
yyyyyyy) |
zzzzzzz) |
aaaaaaaa) |
bbbbbbbb) |
cccccccc) |
dddddddd) |
eeeeeeee) |
|
ffffffff) |
gggggggg) |
hhhhhhhh) |
iiiiiiii) |
jjjjjjjj) |
kkkkkkkk) |
llllllll) |
mmmmmmmm) |
nnnnnnnn) |
oooooooo) |
pppppppp) |
qqqqqqqq) |
rrrrrrrr) |
ssssssss) |
tttttttt) |
uuuuuuuu) |
vvvvvvvv) |
|
|
MEMBERSHIP CODE |
wwwwwwww) |
xxxxxxxx) |
yyyyyyyy) |
zzzzzzzz) |
aaaaaaaaa) |
bbbbbbbbb) |
ccccccccc) |
ddddddddd) |
eeeeeeeee) |
fffffffff) |
ggggggggg) |
hhhhhhhhh) |
iiiiiiiii) |
jjjjjjjjj) |
kkkkkkkkk) |
lllllllll) |
mmmmmmmmm) |
|
nnnnnnnnn) |
ooooooooo) |
ppppppppp) |
qqqqqqqqq) |
rrrrrrrrr) |
sssssssss) |
ttttttttt) |
uuuuuuuuu) |
vvvvvvvvv) |
wwwwwwwww) |
xxxxxxxxx) |
yyyyyyyyy) |
zzzzzzzzz) |
aaaaaaaaaa) |
bbbbbbbbbb) |
cccccccccc) |
dddddddddd) |
|
|
eeeeeeeeee) |
ffffffffff) |
gggggggggg) |
hhhhhhhhhh) |
iiiiiiiiii) |
jjjjjjjjjj) |
kkkkkkkkkk) |
llllllllll) |
mmmmmmmmmm) |
nnnnnnnnnn) |
oooooooooo) |
pppppppppp) |
qqqqqqqqqq) |
rrrrrrrrrr) |
ssssssssss) |
tttttttttt) |
uuuuuuuuuu) |
Proof-reading where the person reads the data that has been entered onto the system and compares it with the original document. Any incorrectly entered data will be edited.
Membership code is unique and can be used as reference for searching.
a. By using the modulus eleven methods the final digit of a number is determined by a formula that uses all the previous digits. So if the number’s been entered incorrectly, the check digit will be wrong.
b. When the membership code is inputted the computer will calculate the check digit and then compared the results with the check digit in the code. If the two are the same the input will be accepted else it is rejected.
Question 7
Data logging means using a computer to automatically record data as it is produced over a period of time.
i. Temperature sensor
ii. Analogue to digital converter
iii. The maxima and minima temperature can be calculated
iv. The temperature data can be displayed in tables displaying the mean and range.
v. The temperature can be displayed in the form of graphs such as bar charts and line charts.
Question 8
Buttons
Date
Time
Question 9
1) Temperature sensor
2) Water level sensor
3) Input valve to control the flow of water in the tank
4) Heater to regulate the temperature of the water
The temperature and water level sensors are connected to the analogue to digital converter which transmits the digital signals to the computer for analysis. If the computer detect the water level in the tank is below the low water level mark then open the water valve. If the water level in the tank is above the high water level mark then close the water valve. If the temperature is too low, turn on the heater. If the temperature is too high, turn off the heater.
Question 10
Transaction files are used to hold temporary data such as latest examination results which is needed to update the master file.
The master file is the most complete and up-to-date file that stores the details of all the students.
i. Codes are shorter therefore faster to input and easier to validate.
ii. Using codes help to save storage spaces.
iii. Backup files can be kept in another building in a fireproof and waterproof safe to protect against fire, flood or theft.
iv. Issue user identity and password to those users who are allowed to access the files.
v. Install anti-virus software to protect the data files from viruses attack.
Students have the right to check for errors and also ask for the errors to be corrected.
Question 11
{Initialisation}
READ mark
lowest = mark
highest = mark
total = mark
{Process rest of marks for class}
{Loop to read next 29 marks}
FOR i = 2 to 30 DO
READ mark
IF mark is less than lowest THEN
lowest = mark
ENDIF
IF mark is greater than highest THEN
highest = mark
ENDIF
total = total + mark
NEXT i
{Calculate result}
range = highest – lowest
average = total/30
{Display results}
PRINT lowest, highest, range, average
i. A team of programmers can work on different modules of the program at the same time.
ii. Individual modules can be tested and therefore it is easier to detect and correct errors.
