Networks & Communications

In this post, we'll take a look at several common terms where networks are concerned.

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Node

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In a network, a node is a connection point that functions as a redistrubution point (to forward) or an end point (the destination) for data transmissions. A physical network node may be a data circuit-terminating equipment (DCE) that performs functions such as signal conversion and coding such as a modem. They may also be a data terminal equipment (DTE) that converts user information into signals or reconverts signals such as a printer. In a local area network (LAN) or the Internet, the nodes are ususally host computers.

A modem is an example of a physical node.
Source: http://www.computerwar.com.my/images/modem.jpg

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Client

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In computing, a client is an application or system that accesses a remove service on another computer system known as a server via a network. In the Internet, a web browser connecting to a service is a client. Similarly, instant messaging applications and online games are forms of clients that connect to a remote server.

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Server

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The HP MediaSmart Home Server.

Source: http://www.wired.com/images/productreviews/2009/01/pr_hp_mediasmart_server_350_f.jpg

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A server is a computer application that delivers a service, such as a web server delivering web pages requested by a browser or client. The data transmission between a client and a server is regulated by a protocol such as the Hyper Text Transfer Protocol (HTTP) between a web browser and a server.

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Hub

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A hub is a physical device in a wired network that connects Ethernet cables from several devices together, allowing each device to communicate with the others. Hubs are fairly simple devices requiring no manuals or configuration, but have largely been rendered obsolete because its functionality has been integrated into other devices such as routers or modems.

A Netgear hub.

Source: http://www.superwarehouse.com/images/products/netgear_ds108.jpg

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Network Interface Card (NIC)

A PCI network card.

Source: http://www.district-85.com/images/resource/devices/nic.jpg

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Network interface cards or network cards are a type of expansion card typically built for PCI slots to provide a system with the ability to connect to a network. Wireless network cards allow network connectivity wirelessly while Ethernet network cards allow a system to access a network via an Ethernet connection. Many modern motherboards usually provide an integrated network interface.

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Network Operating System (NOS)

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A network operating system is a type of OS designed to allow a computer to serve requests from other computers via its own components and programs for data and provides access to other resources and devices such as file systems and printers. Some standalone operating systems such as Mac OS X and every Windows OS since Windows 2000 contain NOS features. Examples of dedicated network operating systems include Cisco IOS and Windows NT.

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Distributed Processing

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'Distributed processing' refers to multiple computers on a network interacting with each other to achieve a common goal. Programs running on a distributed system are referred to as distributed programs. Distributed processing is commonly used in situations such as when data is produced at one location but is needed at another. Distributed processing may also involve distributing tasks to idle CPUs on the network so that the load on each CPU is smaller.

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Host Computer

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A host computer is a node on a network that can host information resources as well as application software for providing network services. Every host is a physical network node. Host computers are usually used by the network managers or administrators of the network.

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Network Manager

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A network manager or a network administrator is a person whose job is to maintain the computer hardware and software of a computer network, including managing network equipment. A network manager concentrates on the overall health of the network, server deployment, security, and manages the network connectivity within that network.

Input & Output

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Magnetic Ink Character Recognition (MICR)

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Magnetic Ink Character Recognition (abbreviated as MICR) is a technology involving the recognition of characters printed with a magnetic ink or toner, usually containing iron oxide (hence the magnetic properties of this technology). It is commonly used in the banking industry for the processing of cheques. A MICR machine first magnetises the characters before they are passed over the machine's read head, producing a unique waveform that is identified by the system.

A closer look at the characters detectable via MICR is shown in green on a cheque.
Source: http://doit.ort.org/course/input/images/287.gif

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Optical Character Recognition (OCR)
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A DILETTA TDR400 OCR machine.
Source: http://diletta.org/Graphic/TDR400%20OCR.jpg

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Optical Character Recognition (abbreviated as OCR) is the recognition of printed or written text characters by a computer, usually involving dedicated software by first photoscanning each character in the text, analysing the image and then translating it into character codes such as ASCII. It is used to digitally preserve library collections and has also been used to sort the mail.
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Optical Mark Recognition (OMR)
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Optical Mark Recognition or Optical Mark Reading (abbreviated as OMR) is the process of digitally recognising human-marked data from forms and test slips. Most conventional OMR machines use a dedicated scanner that emits a beam of light onto dedicated OMR forms. The difference in reflectivity at determined positions of the form is used to detect marked areas. One of the most familiar uses of OMR is on the answer sheets of examinations where candidates are required to use a specific grade of pencil.

An OMR answer sheet.
Source: http://iam0101.new21.net/zbxe/files/attach/images/1916/309/211/omr-form.jpg

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Dot Matrix Printer

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A dot matrix printer (also known as an impact matrix printer) is a computer printer that prints characters and illustrations with a printing head that moves back and forth in two directions along the printer by impacting pins against an ink ribbon to print closely spaced dots in the appropriate shape and formation. Dot matrix printers can print to multi-page forms and can print over a continuous sheet of paper instead of just multiple sheets of paper. However, dot matrix pritners are relatively noisy and tend to have limited printing quality.

A Panasonic dot matrix printer.

Source: http://img.alibaba.com/photo/104543319/Panasonic_Dot_Matrix_Printer_KX_P1121.jpg

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Plotters

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A plotter is a versatile vector graphics printing tool often confused with a printer, but uses line drawings instead of forming images with dots to print graphical plots. A common type of plotter is the pen plotter, which holds a drawing tool such as a pen or pencil with a mechanical arm to draw lines on paper. On the other hand, electrostatic plotters produce a raster image by charging paper with a high voltage which attracts the toner and melts it down into the paper with heat. They are comparatively fast, but are considered to be of inferior quality to pen plotters. Plotters may be connected to a computer or function independently. Plotters may be used to create layouts, diagrams and banners.

An electrostatic plotter.

Source: http://www.recycledgoods.com/zoom_s_p_12109_01.jpg.ashx

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Photo Printer

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A Canon photo printer.

Source: http://www.digitalworldtokyo.com/entryimages/251105_Canon_Printer.jpg

A photo printer is a type of printer (usually of the inkjet variety) used to print high quality digital photographs on specialised photo paper. Because of the need for high levels of detail, these printers usually have many nozzles and are able to print droplets as small as 1 picolitre. What commonly differentiates photo printer from conventional inkjet printers is the usage of additional specialised cartriges to increase the printer's colour range in order to produce more vivid and realistic images. It must be noted that a marketing ploy exists where conventional inkjet printers are marketed as photo printers because there are no official specifications of what makes an inkjet printer a photo printer.

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Portable Printer

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A Zink Polaroid PoGo Portable Printer

Source: http://gopaultech.com/files/2009/03/zink-polaroid-pogo-portable-printer.jpg

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A portable printer is, like its name implies, a printer designed for portability. They are usually compact and rely on an internal power source like a battery. This allows users to connect their digital cameras to the portable printer and supply it with paper to print their photographs on the spot without a computer.

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Fax Machine

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A Samsung fax machine.
Source: http://en.wikipedia.org/wiki/File:Samfax.jpg

A fax (short of fascimile) machine is used in telecommunications to transfer copies of documents over a telephone network. It consists of an image scanner, modem and a printer. A fax machine scans documents documents fed to it similar to the way scanners do to be sent digitally to the receiver and is able to print received documents. While most businesses currently retain some form of fax capability, they are increasingly becoming forgone for Internet-based systems.

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Multifunctional Devices

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A multifunctional device (also known as a Multi Function Product/Printer/Peripheral or an all-in-one) is a machine typically used in offices that possess the functionality of two or more devices, saving space that would otherwise be taken up by individual dedicated machines. A typical multifunctional device may have a combination of printer, scanner, photocopier, fax and e-mail capabilities.

A Canon IR2270 office multifunctional printer.

Source: http://en.wikipedia.org/wiki/Multifunction_printer

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Internet Telephone

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The term 'Internet telephone' typically refers to vocal communication over the Internet using the Voice over Internet Protocol (VoIP). This may include live calls or voice messages which are sent through the Internet as opposed to a public telephone network like conventional phones. This form of communication allows flexibility as more than one call may be transmitted simultaneously over a single connection. It also tends to have lower operational costs because of the way Internet services are billed compared to regular telephone calls. VoIP is commonly integrated with many Internet services such as instant messaging programs. However, dedicated VoIP phones also exist.

A Cisco VoIP phone.

Source: http://en.wikipedia.org/wiki/Internet_telephone

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Telephony

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'Telephony' refers to the general use of equipment to provide voice communication over distances by connection telephones together. Most modern telephones today are plugged into telephone jacks. 'Digital telephony' is the usage of digital technology in telephony. Almost all calls are provided this way, with the conversion between digital and analogue signals taking place inside the phone. IP telephony uses an Internet protocol to transmit voice data - essentially VoIP.

System Unit

This post will detail several parts of a system unit including the interfaces on a motherboard.

Expansion Card

An expansion card is a printed circuit board (often abbreviated to 'PCB') that is attached to an expansion slot of the motherboard of a computer system for additional functionality. The contacts or edge connectors on the edge of the card are designed to fit specific slots such as Peripheral Component Interconnect (PCI) or PCI-Express slots. Below are several examples of expansion cards.

The ATI Radeon HD 5870 - currently the most powerful commercially available single graphics card in the world, built for PCI-E 2.0 x16 slots.

Source: http://www.modreactor.com/images/stories/news/2009/September/10/Radeon_HD_5870_03.jpg

The Creative Sound Blaster X-Fi Xtreme Audio sound card is built for PCI slots.
Source: http://asia.creative.com/products/product.asp?category=1&subcategory=873&product=15855&nav=2&listby=usage

Network Interface Card (NIC)

Network interface cards or network cards are a type of expansion card typically built for PCI slots to provide a system with the ability to connect to a network. Wireless network cards allow network connectivity wirelessly while Ethernet network cards allow a system to access a network via an Ethernet connection. Many modern motherboards usually provide an integrated network interface.

A PCI network card.

Source: http://gizmodo.com/assets/resources/2007/08/network_card2.jpg

Plug & Play

'Plug & play' describes the functionality of which new hardware devices are automatically detected and configured by and for a system and may typically be used without the manual installation of drivers. Plug & play devices may include the mouse, keyboard and monitor. This functionality is also common on USB devices.

CPU Sockets

A CPU socket or CPU slot refers to the component on a motherboard designed to house a microprocessor. They physically support the CPU, provide support for CPU heatsinks and other CPU coolers, forming an electrical interface between the microprocessor and the motherboard and allowing interchangeability of CPUs compatible with the slot.

An AM3 socket on an AMD motherboard for AMD Phenom II, Athlon II and Sempron processors.

Source: http://en.wikipedia.org/wiki/Socket_am3

Chips

A chip is a small integrated circuit manufactured on a thin wafer of semiconductor material. On a motherboard, a chipset refers to a group of integrated circuits that manages the transportation of data from various components by a bus. Typically, motherboards are identified by their chipsets, including what processors are compatible with them. For instance, an Intel X58 chipset motherboard will support Intel Core i7 CPUs. Chipsets may also support multi-GPU technology by graphics card manufacturers Nvidia and ATI (Scalable Link Interface or SLI and CrossFire respectively) if the motherboard has two AGP or two PCI-E x16 slots.

Slots

On a motherboard, slots are similar to sockets that allow for the connectivity of additional components or devices based on the type of slot. The ubiquitous Universal Serial Bus (USB) port is also considered a slot. Other types of slots include the now-obsolete Accelerated Graphics Port (AGP) slots and Peripheral Component Interconnect-Express (PCI-E) slots.

An old AGP slot, circled in yellow.

Source: http://www.tips4pc.com/images/agp_slot.jpg

Bus Lines

In computer architecture, a bus is a subsystem that transfers data between components inside or between computers. Buses may be parallel wires which carry data parallel across multiple wires or in serial form where data is transferred one bit at a time. The bus bandwidth determines the amount of data that can be transferred at once. The bit rate of the bus is dependent on the type of the bus.

Serial Port

A serial port is a physical interface that allows the transfer of data one bit at a time. Data transfer through such ports connects a computer to terminals and peripherals. In modern computers, serial ports are mostly obsolete, being replaced with USB and FireWire, but are still used in certain industrial products and shop till systems.

A male DE-9 connector used for a serial port on a IBM PC compatible computer.

Source: http://en.wikipedia.org/wiki/Serial_port

Parallel Port

Also known as a printer port or Centronics port, a parallel part is similar to a serial port, but data is transferred via parallel communication instead, where several data signals are sent simultaneously over several parallel channels.

A DB-25 parallel printer port, as on IBM-PC style, and a few other types of computers.

Source: http://en.wikipedia.org/wiki/Parallel_port

Universal Serial Bus

The basic USB trident logo; each released variant has a specific logo variant.

Source: http://en.wikipedia.org/wiki/USB

Universal serial bus (often abbreviated to 'USB') is an external bus standard intended to replace most serial and parallel ports. USB is typically used to connect various computer peripherals such as mice, keyboards, gaming controllers, digital cameras and external storage devices.

FireWire Port

Illustrations of various forms of IEE 1394 ports.

Source: http://doctormo.files.wordpress.com/2009/07/firewire-ports.png?w=450&h=230

A FireWire port is a physical interface using the IEEE 1394 interface as a serial bus interface standard for high-speed data transfer and is commonly used in computers for digital video, digital audio, automotive and aeronautics applications. Most digital camcorders support IEEE 1394 connectivity to transfer footage to a system. The second amendment of the FireWire interface, FireWire 800 (IEEE 1394b) has been proven to be substantially faster than Hi-Speed USB. It must be noted that 'FireWire' is Apple's brand name for the interface while Sony refers to it as i.LINK.

Gaming on a Budget: My Custom-built Rig

This post is essentially a compilation and reworking of two posts, here and here, from my actual blog, The Burning Teapot. They're quite related to this blog, so I decided to dump it here. Maybe I just got bored and wanted something to do with this blog after covering careers in IT.

Pre-built desktop PCs are usually major ripoffs, period. They probably attempt to justify their prices with the service charge for assembling and delivering the system among other things, setting it up and stuffing the thing with bloatware, not to mention extended warranties you can pay for, because if you were to actually purchase the exact same (or better, even) parts yourself and assemble the PC on your own, you'll probably end up saving a lot of money.

So early this year, I actually got my very first own custom-built PC. Okay, since it's not custom-built by me since my father was paying for it and assembled it before I could even get to the hardware, but it's still custom nonetheless. I think it's for a certain exam last year, but let's not go there. I'm not exactly well-versed in the inner workings of computer hardware, but what the heck:

Pardon my crappy Nokia 2630's horrible camera quality. If you're wondering what that blue circular thing is, it's actually an air vent that lets you look inside the casing. The blue is from a fancy aftermarket blue LED fan. There's actually another air vent below it, but it's pretty hard to spot with the disgustingly bad image quality.

Here, have some shiny hardware brand stickers while we're at it:

Clockwise from top-left: "Powered by Asus www.asus.com", "Fueled by Sapphire ATI Radeon Graphics", "Intel Pentium Dual-Core inside"

It's got some cheap lame matte black plastic and aluminium casing from a Taiwanese brand, iCute.

As of the time of this post, some of the lights on that pretty blue LED fan are no more. They died.

Let's move on to what's inside it:

- Intel Pentium Dual-Core E5200: Featuring stock clocks of 2.5 GHz, a bus speed of 800 MHz and a rather sad (but not as sad as some AMD offerings) 2 MB L2 cache, the E5200 is essentially a Core 2 Duo on a budget. Some sources state that it actually shares the same Wolfdale architecture from the Core 2 Duo line, but is marketed as a Pentium Dual-Core.

- 2 GB of DDR2 667 RAM: 2048 MB, if you want to be a bit more precise. Two old 1 GB sticks of RAM found in a box somewhere around the house. I have no idea where they came from.

- Asus P5KPL-AM: A really cheap Intel G31 chipset-equipped ATX form factor motherboard. I'm not very familiar with this, but apparently it has very few expansion slots, including one rather dated PCI-E x16 slot. The sad thing here is that it doesn't even have IEEE 1394/FireWire connectivity, so for a previous assignment I had to connect the DV camcorder to another PC before transferring the footage over. What a pain.

- Sapphire ATI Radeon HD 4830: On the budget end of ATI's enthusiast-oriented HD 4800 series is the 512 MB HD 4830, which is currently being phased out in favour of the cheaper HD 4770. Stock, it clocks at 575 MHz at the core and 900 MHz on the memory.

Ignore the scary chick with the dual katanas. The card's blue PCB and dual-slot fan are so much cooler.

Source: http://www.overclockersclub.com/reviews/sapp_4830/2.htm

In order to address the common heat issue in ATI's RV770 cards, Sapphire decided to equip their HD 4830 with an aftermarket dual-slot fan. I got mine for cheaper than other brands' iterations of the HD 4830, too.

- Cooler Master eXtreme Power Plus 500W: The stock power supply that came with the crappy cheap casing just wouldn't do.

The PC also has some apparently extremely popular (probably due to its cheapness) Samsung DVD reader/writer and an old diskette drive, of all things, as well as two hard drives - an old 80 GB one from my sister's ancient Shuttle PC and a 120 GB one of unknown origins.

Also wired up to the PC is a Creative SBS A200 speaker system (2 speakers and 1 subwoofer, basically) I got from the All IT Hypermarket at The Curve during its opening. Creative really messed up with the design of the speakers. Its centre of gravity is pretty far back, so it tips over easily. I can't get an actual shot of it since my subwoofer's on the floor (if I left it on the table, everything else on it would be jumping around from the vibrations), so here:

Source: http://asia.creative.com/products/product.asp?category=4&subcategory=789&product=16973&listby=

Also, this really wasn't part of the plan, nor is it exactly a budget item, but I got an Acer H233H monitor for my birthday this year.

It measures 23" diagonally with a native resolution of 1920 x 1080 - that's full HD 1080p - and a contrast ratio of 40000:1.

I actually had a little trouble finding a wallpaper that matches my native resolution.

What I really like about it is its aesthetics - it comes in a glossy piano black finish and has backlit buttons. Well, technically it has only one button to turn it on and off - the rest are touch-sensitive.

I tend not to do performance benchmarks, but just for the record, I've managed to run EA's Need for Speed Undercover with all its settings maxxed out with anisotropic filtering and 2x anti-aliasing at a rather solid 40 frames per second, though that may drop to around 27 at the beginnings of races when there's lots of cars and smoke onscreen.

I know screenshots don't really mean anything in performance benchmarks, but here's a really nice screenie I shot some time ago.

I've also managed to run Mirror's Edge at my native resolution on its High settings - just one notch short of its maximum Very High. My framerates were mainly around the 40 to 60 fps range.

Anyone up for some over-the-top video game first-person view parkour?

Finally, we have Bethesda Softworks' most recent masterpiece, Fallout 3. The game must have a really well-optimised engine or something, because I somehow managed to max all my settings out at my native resolution of 1920 x 1080, albeit without anti-aliasing and anisotropic filtering with a rather stable average framerate of 40 fps.

Enter post-apocalyptic Washington D.C.

That about sums it up. I'm going to be called a nerd non-stop now. Have fun.

Careers in IT

IT is a relatively diverse but incredibly popular field of study and work that is quickly reaching (or has reached, according to certain sources) a saturation point in Malaysia, career-wise. This may have much to do with the general perception that IT, being a rapidly developing field is the 'in' thing to do, supposedly ensuring a stable and successful future. In certain ways the bandwagon effect may play a major role in the general state of affairs (thought admittedly, the same thing could be said about any other field, depending on its apparent popularity among a specific group of acquaintances, at least on a pre-university level).

This post will briefly explain the variety of careers in the aforementioned field (and sound like a cheap online guide in the process).


1. Webmaster

Also known as a web developer, a webmaster is tasked with the maintenance of the proper functioning of one or more websites. A webmaster's duties may also extend to ensuring the accurate operation of web servers and their software, building and designing a website and examining a website's traffic. Hence, a webmaster typically requires skills in HTML coding and scripting languages such as PHP and Javascript as well as the technical know-how to manage web servers as a server administrator. Depending on the nature of the website managed, creativity and a good sense of ergonomics are favourable traits in a webmaster.


2. Computer Support Specialist

In a nutshell, computer support specialists help people use computers. They often help solve system-related issues encountered by end users or educate them on how to perform specific tasks on their systems. Many computer support specialists work through the phone, e-mail or even offer live chat services. They may also help face-to-face. Computer support specialists may also install hardware, software and teach people how to use them verbally or through instruction manuals that they may write. Some computer support specialists may monitor the systems in a local area network or place daily to ensure that they are functioning properly. A computer support specialist is required to be well-equipped in terms of knowledge on the inner workings of computer systems. They should also be good listeners, problem solvers and are able to articulately give clear and concise instructions.


3. Technical Writer

Technical writing is a very diverse field that is not limited to IT alone. While technical writers may prepare user manuals and documentation for system software (most notably the 'Help' section) and hardware, they may also cover industrial machinery as well as design and engineering specifications for construction projects. Technical writers require the skill to prepare clear and effective written communication and a broad knowledge in the field in which they work.


4. Software Engineer

The meaning of the term 'software engineer' is still highly debated, but it is often used interchangably with the terms 'software developer' and 'programmer'. Software engineers apply the principles of software engineering - the application of a systematic, disciplined, quantifiable approach to the development, operation and maintenance of software - to the development and evaluation of software and systems that make anything containing the software work. Software engineers are generally expected to have programming skills and knowledge in programming languages such as C++. Good problem-solving and analytical skills are generally favourable in a software engineer.


5. Network Administrator

Network administrators are tasked with the responsibility over and maintenance of computer networks and are usually familiar with major networking products such as those from Cisco Systems. They are responsible for overseeing the installation and updates to any software and hardware on the network and are often consulted regarding the creation of a new network or upgrades on a current network. A network administrator usually has an account with master access credentials on a network, allowing he or she to interact with any function in the system. Like many other IT careers, good problem-solving and analytical skills are favourable in a network administrator.


6. Database Administrator

Like network administrators, database administrators have responsibility over and are tasked with the maintenance of a database environment including designing and implementing the system in addition to establishing policies and procedures involving the management, security, maintenance and use of the database system. Database administrators are expected to have good managerial skills and experience with major database management products such as Structured Query Language (SQL) and Oracle-based database management software.


7. System Analyst

A system analyst is a middleman, assessing the needs of end users and translating them into programming or forwarding the programming needs to an appropriate department. System analysts are responsible for researching, planning, coordinating and recommending software and system choices to meet an organisation's needs. Companies generally favour system analysts with programming backgrounds. Analytical, technical, managerial and interpersonal skills are also favoured.


8. Programmer

A programmer is a person that writes computer software. Similar to software engineers, programmers require a solid programming background including proficiency in a programming language. A programmer's primary programming language is often prefixed to their title. There is much debate over the usage of the term 'programmer' being used interchangably with 'software engineer', but the general consensus is that 'software engineer' sounds more credible. One (not necessarily accurate) way to view it is that while programmers may code any kind of program in general, software engineers are more specialised and/or take on some roles of a systems analyst.

Sources & Further Reading:

http://en.wikipedia.org/wiki/Webmaster

http://www.bls.gov/k12/computers02.htm

http://www.wisegeek.com/what-does-a-technical-writer-do.htm

http://en.wikipedia.org/wiki/Software_engineer

http://www.wisegeek.com/what-is-a-network-administrator.htm

http://searchsqlserver.techtarget.com/sDefinition/0,,sid87_gci214169,00.html

http://www.princetonreview.com/careers.aspx?cid=210

http://en.wikipedia.org/wiki/Systems_analyst

http://en.wikipedia.org/wiki/Programmer

http://www.inter-sections.net/2007/11/13/how-to-recognise-a-good-programmer/

http://answers.yahoo.com/question/index?qid=20071020191123AA0UHz8