Hi! I would like to post my C1001 Computers and Information Processing module’s assignment, this was my assignment in Term 1 2008. Well, basically this module is the most basic module in IDIC (International Diploma in Computing) course. The assignment also just consist of simple questions and answer, not much research or self study need to be done.

So, here is my assignment:

1. Three Types of Scanners:

a) Optical Scanner

Optical Scanner is an input device that works using bright light that moves across paper or the document. After that, the image reflected through series of mirror and converted to digital signal by the software.

The image is stored as rows and columns of dots called bitmap.

b) Optical Reader (e.g. Optical Mark Reader)

Optical Reader is a device that able to read characters, marks, or codes from a paper, document, or any physical medium. Then convert it to digital signal that can be processed by the computer.

Kinds of Optical Reader are:

• Optical Character Recognition (OCR)

ü  Scan printed text and convert it to a text document in computer.

• Optical Mark Reader (OMR)

ü  Scan and read hand-drawn mark (e.g. Exam paper)

• Bar Code Scanner

ü  Read bar codes

ü  UPC (Universal Product Code)

c) Magnetic Ink Character Recognition (MICR)

MICR is a device used to scan and read text or code printed with magnetized ink.

Generally, MICR is used in banking environment. For example, a bank use MICR to read the code printed with magnetized ink on a cheque paper.

2. Check digit for student-id 336137 with mod 11 check digit system

Appending check digit:

Ø  Assign weight to true data:

True data	3	3	6	1	3	7
Weightage	7	6	5	4	3	2

7*2      = 14

3*3      =   9

1*4      =   4

6*5      = 30

3*6      = 18

3*7      = 21 ₊

96

Ø  The sum = 96, then we divide it by modulus 11

96 mod 11, gives quotient 8 and remainder 8

Ø  Modulus 11 is subtracted by remainder 8 to get the check digit

Check digit = 11-8 = 3

Ø  The check digit “3″ is  appended to the right of the original student id 336137, which result to be 3361373.

Ø  To verify whether 3361373 is correct, we multiply it with the weight and then see if the sum is divisible by 11.

	3		3		6		1		3		7		3
Weight	7		6		5		4		3		2		1
	(3*7)	+	(3*6)	+	(6*5)	+	(1*4)	+	(3*3)	+	(7*2)	+	(3*1)	=	99

The sum is 99 which is divisible by 11, that mean the check digit is correct.

3. Comparison Table

	PC	Minicomputer	Mainframe	Supercomputer
Physical Size	Small	Big	Bigger	Very Big
Number of Simultaneously connected users	1-10	4000	>4000	Biggest number of users support

4.

a) Basic Network Topologies

i)   Bus Topology

In a network with bus topology, each computer is connected to a central cable called as the backbone cable. There is a terminator attached at both ends of the backbone cable that terminate transmission signal and prevents ringing. Bus topology is a passive topology where each computer in the network just listens to the signal from backbone cable and not responsible to move the data signal to other computer in the network. If there is a data being transmitted, all computers in the network will actually receive the data signal but only the computer with the right address will accept the transmission signal, the rest will just disregard it. Bus topology relies on the main cable (backbone). It’s easy to implement in small network but not suitable for a big network.

ii)  Star Topology

In a network with star topology, each computer is connected to a central controller called as the hub. The hub manages the communication between computers that connected to it. It provides switching service for computers in the network, so a computer who wants to do a data transmission to another computer will send the data to the hub first, and then the hub will relay the data to the intended recipient computer. It is easy to add or remove a computer in star topology. Additionally, this topology support large number of computers in the network. The down side of this topology is when the hub is broken, the entire network will also fail to work.

iii) Ring Topology

In a ring topology, all the computers in the network is connected by a main cable that form a circular ring from first computer to the next computer and so on until it connects back to the first computer. Ring topology is an active network topology where in this topology each computer is responsible of moving data signal to the next computer in the ring. This topology uses a token passing mechanism, a token that moves from one computer to another. Only a computer with a token can use the main cable to start data transmission for a limited amount of time before it has to pass the token to the next computer. So, each computer in ring topology has equal access to the communication medium. This topology is good to handle network with heavy traffic and time sensitive transaction, but it is difficult to modify this network and also if one computer failed to work, the entire network will be fail also.

iv) Mesh Topology

In mesh topology, each computer has a dedicated connection to every computer in the network. This network will guarantee privacy and also fast data transfer between computers in the network because there is no network traffic. But this topology has a downside because it needs a massive amount of cable which is very expensive when applied to a big network with a lot of computers.

4. b) Physical communication media

i) Types of physical communication media:

Ø  Twisted pair cable

o   Un-shielded twisted pair (UTP)

o   Shielded twisted pair (STP)

Ø  Coaxial cable

Ø  Fiber Optic Cable

ii) Comparison of different types of physical communication media:

Factor	UTP	STP	Coaxial	Fiber Optic
Cost	Cheapest	Moderate	Moderate	Most Expensive
Installation	Easy	Fairly Easy	Fairly Easy	Difficult
Bandwidth	10 Mbps	16 Mbps	10 Mbps	100 Mbps - 1 Gbps
Node Capacity for 1 cable segment	2	2	30 (10Base2) 100 (10Base5)	2
Affected by Attenuation	High	High	Low	Lowest
Vulnerability to EMI (Electromagnetic Interference)	Most Vulnerable	Less Vulnerable than UTP	Less Vulnerable than UTP	Not Affected by EMI

5. Difference between serial printer and line printer

a)      Serial Printer

A serial printer is a kind of printer that prints one character at a time. The speed of this kind of printer is measured in characters per second (cps), for example is the dot-matrix printer.

b)      Line Printer

Different from serial printer that prints a character at a time, a Line Printer is a printer that able to print an entire line at a time. The speed of Line Printer is measured in Lines per minute (lpm). Shuttle-matrix printer is an example of line printer.

Do you have any comment on this? maybe you have something to ask me or want to discuss with me about this?Or maybe you are IDIC student and taking this module also?
Feel free to use the comment box below (click here if you cannot see the comment box).

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