CUHK FAA Thomas Cheung Secondary School
S.6 AS Level Computer Applications
Module 1: Computer Systems
Ch2 Computer Systems
Suggested Answer
1.
The computer system consists of both hardware and software. Hardware refers to the actual
machinery, for example, the keyboard, mouse and monitors. Software refers to program or
data.
2.
Keyboard, mouse (or any reasonable answers)
3.
Word processing software, Spreadsheet software (or any reasonable answers)
4.
A CPU consists of two major components: the control unit(CU) and arithmetic and logic unit
(ALU).
The CU controls the overall operations of the computer and controls the operations of the
peripheral devices. It interprets an instruction from a program.
The ALU performs arithmetic operations, such as addition and subtraction of integers. It also
performs logical operations such as comparing two numbers.
5.
The functions of RAM and ROM are different. The function of RAM is a temporary holding
area for data, application programs and operating system, as long as the computer is running.
RAM is volatile. But the functions of the ROM is a permanently holding area for system
program, such as BIOS. ROM is non-volatile.
6.
Data transfer between the CPU and main memory is slow. Very often, the CPU has to wait
for memory access and become idle. Cache memory is a high-speed memory that holds data
which duplicate some data stored in the main memory. When the data needed by the CPU
are stored in the cache memory, the access time will be much smaller than fetching the same
data from the main memory.
When cache is full and the CPU calls for a new instruction, the system overwrites the data in
cache that hasn't been used for the longest period of time. This way, the high priority
information that's used continuously stays in cache, while the less frequently used
information drops out.
7.
CMOS is a type of memory on the motherboard that stores the configuration information
about a computer. It includes information like current time and date, capacity of hard disk,
types of existing port, keyboard and monitor. However, CMOS doesn’t store program.
CMOS memory is powered by a small battery. The contents in CMOS memory are retained
even the main memory power supply is turned off.
8.
The CPU gets data from and stores data onto the memory. Therefore, a channel that links
between the CPU and the memory is needed for data transfer. Similar channels exist between
the memory and the peripheral devices. Each channel, called a bus, allows a series of
electronic bits to transmit at the same time.
A bus consists of three parts: address bus, data bus and control bus. When a control signal in
control bus is read, a piece of data is fetched from the memory, the address is sent over the
address bus to the data bus., which passes the data to the destination.
9.
The expansion slot is built on the motherboard to increase the functionality of the computer
system.
10. Interface buses:
USB
Parallel port
Keyboard port
11.
As the main memory is limited in size, will a computer run out of memory. The solution to
this problem is virtual memory. Virtual memory is an area of a hard disk that extends the
RAM.
If the free space of RAM is less than the size of a new data from a file, data in RAM not
recently used and not frequently used will be put to the virtual memory to make room for the
new data. This process is called swapping. When the data on virtual memory are needed
afterwards, they would be swapped back to the RAM again.
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CUHK FAA Thomas Cheung Secondary School
S.6 AS Level Computer Applications
Module 1: Computer Systems
Ch3 Peripheral Devices
Suggested Answer
1. (a) Advantages: no cluttering of wire at a larger distance.
Disadvantage: require battery
1. (b) Advantage: it is suitable for users who don’t know input Chinese methods
Disadvantage: not suitable for input larger amount of data
1. (c) Advantage: Less hand movement
Disadvantage: not 100% correct because it depends on the users’ pronunciation
2.
Kiosk
Handheld computer
Tablet PC
3.
Touch pad
Point stick
4. (a) In case the bar code reader fails to read the code
4. (b) Speed fast, more accurate and error free
5.
OCR reader, scanner with OCR system, voice input, keyboard, touch screen with handwriting
recognition
6. (a) It means that the contents on the medium can be overwritten.
6. (b) 1. no film cost
2. can be transmitted in electronic form easily and at low cost
3. result can be viewed instantly
4. allow choice of photo before printing
5. easy and unified management using computer
7. (a) Microphone, speaker, DV camera, monitor
7. (b) The computer needs to be able to access the Internet network. Since video involves a lot of
data, the computer must have large enough memory and fast enough CPU to handle the video
as well as sound.
8. (a) It has a processing unit and a memory.
8. (b) It can change the stored content, for example, deducting the deposit. It can programmed to
self-destruct.
9. (a) Authenticating system that detects fingerprint, face geometry, voice, iris pattern.
9. (b) Eliminate fraud using stolen cards.
10. (a) Hardcopies are printed document that can be carried independent of machine.
Softcopies are output in electronic forms. Hardcopies are more permanent.
10. (b) Hardcopies: printer
Softcopies: monitor, speaker
11. (a) An impact printer consists of a hammer that strikes an inked ribbon to produce output on
paper. An impact printer is noisy and slow.
11. (b) Impact printer: dot-matrix;
Non-impact printer: inkjet, laser and thermal printer
12. (a) Quality is measured by dpi
12. (b) Independent
12. (c) Inkjet printer will be blurred by water / the ink on the paper from inkjet printer needs time to
dry.
12. (d) Thermal printer
CUHK FAA Thomas Cheung Secondary School
S.6 AS Level Computer Applications
Module 1: Computer Systems
Ch4 System software and Application software
Suggested Answer
1. (a) (i)
Examples of application program:
Word processing software
Power Point software
Web browser
1. (a) (ii)
Example of utility program:
Disk defragmenter
Diagnostic utility
Uninstaller
1. (a) (iii) Examples of driver program:
Printer driver
Scanner driver
Web cam driver
1. (b)
An operating system is a set of programs that controls the operations of a computer
system, manage resources and provides an environment for users to access various parts
of the computer system easily.
2. (a)
Graphical user interface
2. (b)
3 common features”
Icons: a small picture that represents a command
Menu: a set of user commands displayed in text
buttons and graphic objects: represents a command
2. (c)
Pointing devices, like mouse, graphic tablet
2. (d)
GUI: windows
Command line interface: DOS
2. (e)
Advantages:
GUI: 1) intuitive to use so that it is easy to use
2) user need not learn a set of instructions to operate the system
CLI: 1) fast for experienced user
2) less resource demanding
3. (a)
a) applications
b)
c)
d)
e)
utility
applications
application
application
4. (a)
Word processing software, presentation software, drawing program, photo-editing
program software
4. (b)
He can open both word processing software. Copy text from the word document and
paste onto the presentation.
4. (c)
Multi-tasking
5. (a)
A screen saver causes a monitor to display a moving image or blank screen if no
keyboard or mouse activity occurs for a specified time. Screen savers were developed
images could be permanently etched on a monitor’s screen.
5. (b)
The screen saver will lock the computer if it is idle for a certain period for security. This
is based on the assumption that the user has left his/her seat already.
6. (a)
Utility program allows user to manage a computer, including its devices and programs,
while application program help user to finish a task.
6. (b)
Utility program
6. (c)
Frequently download virus definition file from the Internet.
7. (a)
1. hard disk free space too low
2. Files are fragmented
7. (b)
1. delete unnecessary files
2. use defrayments utility program to rearrange the files on the hard disk
8. (a)
The storage size of a floppy disk is only 1.44MB.
8. (b)
She should compress the file using the file compression utility.
8. (c)
Peter must have the corresponding file decompressed utility program in order to open
the file.
9. (a)
The program is a disk scanner utility which detects and corrects problems on the hard
disk.
9. (b)
System software
9. (c)
Yes. She should regularly use this program to make sure that her computer is in good
health condition.