Communication and Network

Physical Connection
Twisted-Pair

Twisted pair is the ordinary copper wire that connects home and many business computers to the telephone company. To reduce crosstalk or electromagnetic induction between pairs of wires, two insulated

copper wires are twisted around each other. Each connection on twisted pair requires both wires. Since some telephone sets or desktop locations require multiple connections, twisted pair is sometimes installed in two or more pairs, all within a single cable.

Coaxial Cable

Coaxial cable is the kind of copper cable used by cable TV companies between the community antenna and user homes and businesses. Coaxial cable is sometimes used by telephone companies from their central office to the telephone poles near users.




Fiber-Optic Cable

A technology that uses glass (or plastic) threads (fibers) to transmit data. A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves.

Network Terms

Node

In a network, a node is a connection point, either a redistribution point or an end point for data transmissions. In general, a node has programmed or engineered capability to recognize and process or forward transmissions to other nodes.

Client

A client is the requesting program or user in a client/ server relationship. For example, the user of a Web browser is effectively making

client requests for pages from servers all over the Web. The browser itself is a client in its

relationship with the computer that is getting and returning the requested HTML file. The computer handling the request and sending back the HTML file is a server.

Server

In information technology, a server is a computer program that provides services to other computer

programs (and their users) in the same or other computers. The computer

that a server program runs in is also frequently referred to as a server (though it may be used for other purposes as well).

Hub

A common connection point for devices in a network. Hubs are commonly used to connect segments

of a LAN. A hub contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

Network Interface Card ( NIC)

Often abbreviated as NIC, an expansion board you insert into a computer so the computer can be connected to a network. Most NICs are designed for a particular type of network, protocol, and media, although some can serve multiple networks.

Network Operating System (NOS)

A network operating system (NOS) is a computer operating system system that is designed primarily to support workstation, personal computer, and, in some instances, older terminal that are connected on a local area network (LAN) Artisoft's LANtastic, Banyan VINES, Novell's Netware, and Microsoft's LAN Manager are examples of network operating systems. In addition, some multi-purpose operating systems, such as Windows NT and digital's openVMS come with capabilities that enable them to be described as a network operating system.

Host Computer

In computer networking, a network host, Internet host, host, or Internet node is a computer connected to the Internet - or more generically - to any type of data network. A network host can host information resources as well as application software for providing network services.

Network Manager

NetworkManager is a software utility aimed at simplifying the use of computer network on Linux and other Unix-Like operating systems.The project was initiated in 2004 by Red-Hat, with the goal of enabling Linux users to more easily deal with modern networking needs, particularly wireless networking. NetworkManager takes an opportunistic approach to network selection, attempting to use the best available connection as outages occur, or the user roams between wireless network. Ethernet connections are preferred over “known” wireless networks, which are preferred over wireless networks with SSIDs to which the user has never connected. The user is prompted for WEP or WPA keys as needed.

Secondary Storage

Performance Enhancement

Three ways to improve the performance of hand disks are:

Disk caching

A portion of RAM used to speed up access to data on a disk. The RAM can be part of the disk drive itself (sometimes called a hard disk (cache or buffer) or it can be general-purpose RAM in the computer that is reserved for use by the disk drive (sometimes called a soft disk cache). Hard disk caches are more effective, but they are also much more expensive, and therefore smaller. Nearly all modern disk drives include a small amount of internal cache.

Redundant arrays of inexpensive disks (RAID)

technology that allowed computer users to achieve high levels of storage reliability from low-cost and less reliable PC-class disk-drive components, via the technique of arranging the devices into arrays for redundancy.

File compression and decompression
The file compression and decompression take an existing file or files and produce a file or files that are compressed versions of the originals. The compression is also lossless, but the compression is not transparent to applications. An application can only operate on such files with the assistance of a file compression library. In addition, the only operations you can perform on such files are creating a compressed file from an original and recovering the original data from the decompressed version. Editing is typically not supported, and seeking is limited if supported at all.

Input and Output

Magnetic Ink Character Recognition (MIRC) is a character recognition technology that printed in a special typefaces with a magnetic ink or toner and used primarily by banking industry to facilitate the processing of cheque.The technology allows computers to read information (such as account numbers) off of printed documents. Unlike barcodes, however, MICR codes can be easily read by humans.

Optical-Character Recognition (OCR) is the recognition of printed or written text characters by a computer. This involves photoscanning of the text character-by-character, analysis of the scanned-in image, and then translation of the character image into character codes, such as ASCII, commonly used in data processing.





Optical Mark Recognition (OMR) also called Optical Mark Reading and OMR is the process of capturing human-marked data from document forms such as surveys and tests. In computing, a technique that enables marks made in predetermined positions on computer-input forms to be detected optically and input to a computer. An optical mark reader shines a light beam onto the input document and is able to detect the marks because less light is reflected back from them than from the paler, unmarked paper.




Dot- Matrix Printer is a type of printer that produces characters and illustrations by striking pins against an ink ribbon to print closely spaced dots in the appropriate shape. Dot-matrix printers are relatively expensive and do not produce high-quality output. However, they can print to multi-page forms (that is, carbon copies), something laser and ink-jet printers cannot do.


Plotter is a a device that draws pictures on paper based on commands from a computer. Plotters differ from printers in that they draw lines using a pen. As a result, they can produce continuous lines, whereas printers can only simulate lines by printing a closely spaced series of dots. Multicolor plotters use different-colored pens to draw different colors.





Photo Printer a photo printer is a printer (usually an inkjet printer) that is specifically designed to print high quality digital photos on photo paper. These printers usually have a very high number of nozzles and are capable of printing droplets as small as 1 picoliter.




Fax Machine is a short for facsimile machine, a device that can send or receive pictures and text over a telephone line. Fax machines work by digitizing an image, dividing it into a grid of dots. Each dot is either on or off, depending on whether it is black or white. Electronically, each dot is represented by a bit that has a value of either 0 (off) or 1 (on).




Multifunctional devices bring the worlds of copying, printing, finishing, and scanning together, all in one neat, efficient and cost-effective package. Highly efficient black-only multifunctional devices as well as a huge range of colour multifunctional devices to meet your particular requirements.




Internet telephone is a category of hardware and software that enables people to use the Internet as the transmission medium for telephone calls. For users who have free, or fixed-price Internet access, Internet telephony software essentially provides free telephone calls anywhere in the world. To date, however, Internet telephones does not offer the same quality of telephone service as direct telephone connections.

System Unit

Expansion Card

An expansion card also known as ad-on card or internal-card. An expansion card is an electronic board or card added in a desktop computer or other non-portable computer to give that computer a new ability, such as the ability to connect to another computer using a network cable.

Network Interface Card

Hardware device that handles an interface to a computer network and allows a network-capable device to access that network. Every Ethernet network card has a unique 48-bit serial number called a MAC address which is store in ROM carried on the card.

Cache Memory

Cache memory is extremely fast memory that is built into a computer's central processing unit (CPU) or located next to it on the separated chip. The CPU uses cache memory to store instructions that are repeatedly required to run programs, improving overall system speed. The advantage of cache memory is that the CPU does not have to use the motherboard's system bus for data transfer.

Plug & Play

Plug and Play (PnP) is a capability developed by Microsoft for its Windows 95 and later operating systems that gives users the ability to plug a device into a computer and have the computer recognize that the device is there.

Sockets

A socket is an endpoint for communication between two machines. Socket classes are used to represent the

connection between a client program and a server program. The java.net package provides two classes--Socket and ServerSocket--that implement the client side of the connection and the server side of the connection, respectively.

Computer Chip

A computer chip is a small electronic circuit, also known as integrated circuit which is one of the basic components of most kinds of electronic devices, especially computers.

Slots
Slots also known as expansion slots because they allow you to expand the capabilities of a computer. The boards you insert in expansion slots are called expansion board or add on board.

Buslines

The bus lines are the communicating electronic lines that connect different parts of the CPU to various other parts. In addition, the bus lines also link the CPU to different parts on the system board of your computer.

Serial Port

In computing, a serial communication physical interface through which information transfers in or out one bit at a time. Throughout most of the history of personal computer, transfer through serial ports connected the computer to devices such as terminals and various peripherals.

Parallel Port

A parallel port is a type of interface found on computer for connecting various peripherals. It also known as printer port or centronics port.

Universal Serial Bus

USB (Universal Serial Bus) is a way of setting up communication between a computer and peripheral devices. USB is intended to replace many varieties of serial and pararel ports.

Firewire Ports

Firewere ports are forms of a serial port that make use of FireWire technology to transfer data rapidly from one electronic device to another. The FireWire port has been in common use since 1995, when Apple, Inc. first began to include the port on a number of digital camcorders. Today, the FireWire port is used on a number of other devices.

The interntet , The web and electronic commerce

1. HTML

HTML (Hypertext Markup Language) authoring language used to create documents on the worldwide web. HTML related to the structure and layout of a web documentby using of a variety of tags and attributes. The correct structure for an HTML document starts with (enter here what document is about) and ends with .

2. Javascript
As known as Jscript in Microsoft . Javascript is a scripting language to enable web authors to design interactive sites. The structure is full of Java language. java can interact with HTML source code. Enabling web authors to spice up their sites with dynamic content.

3. Applets
Applets is a program designed to be excuted from within another appication. Unlike an application, applets cannot be executed directly from the operating system. With the growing popularity of OLE (object linking and embedding), applets are becoming more prevalent. A well-designed applet can be invoked from many different applications.

4. Business-to-Consumer E-Commerce
One of the most common models in E-Commerce is the Business-To-Consumer (B2C) model. In B2C transactions, online transactions are made between businesses and individual consumers. Businesses sell products and services through electronic channels directly to the consumer.

5. Consumer-to-COnsumer E-Commerce
Consumer2Consumer (C2C) or as it is sometimes referred to Peer2Peer (P2P) exchanges involve all transactions between and among consumers. These transactions can also include third party involvement, usually in the form of those who facilitate the marketplace such as E-bay.com. C2C exchanges can include clasified ads, music and file sharing, career and job websites and also personal services such as dating website .

6. File Transfer Protocol

File Transfer Protocol is a network protocol used to exchange and manipulate files over a TCP/IP based network, such as the internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server applications.

7. Filters
Filters is a program that designed for check input or output request for qualifying criteria that process or forward it accordingly. Filters also sometime used to insert header or control characters in data.

No fear : )

Hallo . kira-kira sampe hari ini pas 1 bulan gw berada di Malaysia . Tapi sampai sekarang masih gak nyangka lho kalo gw bisa sekolah di luar negeri . Flashback sedikit, gw sekolah di luar negeri itu keputusan gw ga pake mikir karena waktu itu gw lagi patah hati putus sama cowo pertama gw dan gw uda janji sama diri sendiri bakal mau pergi jauh dan sekolah di luar biar bisa lupain mantan pertama , dan it's work ! gw uda lupain dia an uda rela dia sama cewe lain . Tapi efeknya sekarang gw terdampar disini dan masih tetap gak nyangka karena hal itu gw di Malaysia, jauh dari keluarga dan teman-teman terdekat .
Well, pertama kali sampai disini gw pesimis banget dan banyak hal yang gw takutin dari mulai takut ga dapet temen, takut kesepian, takut gak bisa mandiri sampe takut tidur sendiri (padahal di Jakarta gw tidurnya juga sendiri ahahahahha konyol sekali saya )
Minggu pertama tepatnya 10 hari nyokap temenin gw disini untuk beradaptasi . Well , selama 10 hari penuh dengan shopping dan gw masih gak dapet temen di Malaysia . Nah pas nyokap uda balik ke Jakarta baru gw pusing dan lonely karena gw gak punya temen selain temen-temen gw yang berangkat bareng dari Indo . Dan yang bikin pusing lagi dari yang tadinya gw gak bisa nyuci baju , ngepel , nyapu , setrika dan akhirnya gw harus menghadapi kenyataan kalo gw musti cuci baju sendiri dan apa- apa sendiri , sampe cari makan juga harus cari sendiri . Pas di Indo gw gak perna mikirin sampe situ lho makanya gw agak shock pas ditinggal nyokap hahaha .
Pas masuk college akhirnya dengan sifat gw yang agak SKSD gw dapet la beberapa teman hahaha menyenangkan . Dan akhirnya beberapa jadi teman gw sampe sekarang .
Oh ya sebenarnya sebelum gw pergi ke Malaysia gw uda bisa ngelupain mantan pertama lho . Itu karena waktu itu gw deket sama cowo yang inisial namanya Y . Gw sempet sedih kenapa kenal dia telat sampe harus gw pergi ke Malaysia dulu baru gw sadar kalo dia bisa bikin gw lupain mantan pertama . Sesampai di Malaysia dia juga tetap kontek gw dan temenin gw lewatin hari yang menurut gw si agak susa dilewatin ahahah . Cuma sekarang gw uda gak sama dia lagi karena hubungan long distance amat sangat susah . Gw tau gw bakal nyesel lepasin orang sebaik itu cuma keadaan sini gak memungkinkan , daripada makin lama diterusin tar sama" makin sakit mending gw putusin dari sekarang . toh kalo emang jodoh gak kemana - kemana ya kan . ahahaha . gw jadi curhat di blog ini . Tapi gw harus bisa ambil keputusan lah dan harus ambil resiko dari apa yang gw putuskan karena kata koko angkat gw yang bernama Michael Tan yang biasa dipanggil ameX kata dia kalo mau jadi bos harus bisa ambil keputusan dan terima segala resiko . Itu kenapa gw berani ambil keputusan walo bener" sakit bener dah .
Well maksud gw dari blog ini selain iseng" gw buat karena gak ada kerjaan sekalian kasitau pengalaman gw di Malaysia dan sekarang gw uda kebiasa idup di negara orang . Jadi jangan takut untuk kuliah di Luar Negeri karena setiap ketakutan yang kita rasain sebenernya gak seserem yang kita bayangin kalo kita hadapin dan terus mencoba . Good luck yang bakal mau sekolah di luar . Ingat ketakutan itu cuma berasal dari kita sendiri dan kita yang ciptain .

Careers in iT

Those who really curious about computer system, how it works or want to create a game probably suggested to study iT .

There are many careers in iT such as Webmaster, Computer support specialist, Technical writer, Software engineer, Network administrator, Database administrator, System analyst, and Proggrammer. Some of us maybe didn't know about all the careers yet and i make this blog so it maybe can be more useful for those who really interested about iT and could add more knowledge for us who still didn't know about iT and all the careers.

First of all i would like to explain about Webmaster. Webmaster is a person who creating the website, making sure the hardware and software work properly, and even selling products or services. Being a Webmaster should have a high resposibility because they covered all about website so we can used it more effectively .

The second career is Computer support specialist. Being a Computer support specialist quite fun. We can enabling business and individual users to navigate increasingly complex technology, testing new software for reliability, involve searching for facts and figuring out problems mentally. And being a Computer support specialist must good at Mathematics like arithmetic, algebra, geometry, calculus, statistics, and their applications.

Next career is Technical writer. Technical writer is someone who usually write about technical documentations for technical, business, and consumer audiences. So when the webmaster make a website and the techical writer write the user guides to understand more about the website.

The fourth one is Software engineer. Software engineer is someone who usually testing new software programs, finding fault in programs, and developing existing programs by analysing and identifying areas for modification. Software engineers usually become a specialist in systems and appications. And take a hug number of empoyed.

If you like to oversees the computer networks to ensure they are function smoothly then Network administrator should be suitable for your next future career. A network administrator should be strong it math, sciences and computer sciences. We also need to have a good organizational, and logical thinking skills.

Not like Network administrator, Database administrator used to writing database documentation and managing the performance of database itself, control and securing the database. Increasing the number of hacking makes this job become and important aspect of the work.


Being a system analyst are responsible to provide system-level support of multi-user operating systems, hardware and software tools, including installation, configuration, maintenance, and support of these systems. Identify alternatives for optimizing computer resources. If we want to be a good system analyst we must good at writing, reading and arithmetic skill which we already got them since in high school.

At last , next job is proggramer . Proggramer is a job which create operating systems and another may develop computer games. Proggramer have two jobs in common : they all write code and solve problems .