Using Client/Server Architecture

Client/Server Architecture it is an arrangement used on local area networks that makes use of “distributed intelligence” to treat both the server and the individual workstations as intelligent, programmable devices, thus exploiting the full computing power of each. This is done by splitting the processing of an application between two distinct components: a “front-end” client and a “back-end” server. The client component, itself a complete, stand-alone personal computer (versus the “dumb” terminal found in older architectures such as the time-sharing used on a mainframe) offers the user its full range of power and features for running applications. The server component, which can be another personal computer, minicomputer, or a mainframe, enhances the client component by providing the traditional strengths offered by minicomputers and mainframes in a time-sharing environment: data management, information sharing between clients, and sophisticated network administration and security features. The advantage of the client/server architecture over older architectures is that the client and server machines work together to accomplish the processing of the application being used. Not only does this increase the processing power available, but it also uses that power more efficiently. The client portion of the application is typically optimized for user interaction, whereas the server portion provides the centralized, multi-user functionality.

What is a Computer Program?

Computer Program is a set of instructions that directs a computer to perform some processing function or combination of functions. For the instructions to be carried out, a computer must execute a program, that is, the computer reads the program, and then follows the steps encoded in the program in a precise order until completion. A program can be executed many different times, with each execution yielding a potentially different result depending upon the options and data that the user gives the computer. Programs fall into two major classes: application programs and operating systems. An application program is one that carries out some function directly for a user, such as word processing or game-playing. An operating system is a program that manages the computer and the various resources and devices connected to it, such as RAM (random access memory), hard drives, monitors, keyboards, printers, and modems, so that they may be used by other programs. Examples of operating systems are DOS, Windows 95, OS/2, and UNIX. Software designers create new programs by using special applications programs, often called utility programs or development programs. A programmer uses another type of program called a text editor to write the new program in a special notation called a programming language. With the text editor, the programmer creates a text file, which is an ordered list of instructions, also called the program source file. The individual instructions that make up the computer program source file are called source code. At this point, a special applications program translates the source code into machine language, or object code—a format that the operating system will recognize as a proper program and be able to execute. Three types of applications programs translate from source code to object code: compilers, interpreters, and assemblers. The three operate differently and on different types of programming languages, but they serve the same purpose of translating from a programming language into machine language.

I Phone 3G S: What's new?

The iPhone 3G S sports a faster processor than its predecessor and that its operating system has access to more RAM. There could be changes to the display circuitry, too, which would account for Apple's claims that the iPhone 3G S offers a better gaming experience. According to T-Mobile in the Netherlands, which appears to have accidentally posted the specs for the iPhone 3G S, the latest version of the phone includes 256MB RAM, up from 128MB on the iPhone 3G, and a 600MHz processor. That would be an improvement from the 412MHz version found in the iPhone 3G.Just looking at the surface, not all that much. In fact, we're wiling to bet that if we set an iPhone 3G S next to an iPhone 3G, you'd be hard-pressed to tell which is which--at least until you flipped the phones over. Then, you might notice that the "fine-print" writing on the back of the phone--you know, the part that lists the phone's capacity and tells you that it's designed in California and assembled in China--is now color-matched to the silver Apple logo. The screen is covered with a new oil-resistant, or oleophobic, coating, making it easier to wipe off fingerprints. We watched an Apple executive take an iPhone 3G S and wipe it off with his shirt sleeve, something that wasn't too effective in removing smudges with earlier models. Then again, physical changes usually aren't the focus of these iPhone updates. Apple puts its effort into upgrading the software features offered in new phones. The iPhone 3G S features a compass app that knows which direction you're facing.) The iPhone 3G S has a few features that you won't find in previous models. Just as the iPhone 3G added the ability to figure out your location via GPS (Global Positioning System) satellites, the iPhone 3G S lets you know which direction you're pointing in via a built-in compass. In addition, you can ask your iPhone 3G S to play music--specific songs or playlists.

Computer Memory

Expanded Memory, in computer science, on IBM PCs and compatible computers, a type of physical memory, up to 8 megabytes (MB), that can be added to machines based on the Intel 8086/8088 microprocessor or to machines with 80286/80386/80486 microprocessors running MS-DOS in real (8086-emulation) mode. The use of expanded memory is defined by the Expanded Memory Specification (EMS). Because it represents memory that is not normally accessible to programs running under MS-DOS, expanded memory requires an interface called the Expanded Memory Manager (EMM), which maps pages (blocks) of bytes from expanded memory onto reserved areas called “page frames” in an accessible memory area. Only EMS-compatible software can make use of expanded memory.

Extended Memory, in computer science, system memory beyond 1 megabyte (MB) in computers based on the Intel 80286/386/486 microprocessors. This memory is accessible only when the processor is operating in protected mode or in virtual real mode on the 386/486. Extended memory is not typically available to MS-DOS programs. However, it is available to OS/2 programs and can be made available to MS-DOS programs by the use of software that temporarily places the processor into protected mode or by the use of 386/486 features to remap portions of extended memory into conventional memory based on the EMS conventions.

Digital Movie Formats

With movies selling for P200-P400 each (and pirated, film-transfer versions selling for as low as P50 per movie) and cheap knockoff players (many with clearly fake Sony logo) going for just P2,000-P3,000, Video CD’s (VCDs) are currently all the rage in Manila and elsewhere in Asia. Movies digitally encoded on VCD at least the genuine variety – feature better audio and video quality than older movies on VHS-format videotape. But no mistake, VCD is merely a transitional format. Translation: VCD is on the way out. Movies on VCD are even now being phased out in favor of movies on DVD (Digital Versatile Disc or Digital Video Disc). The reason are simple: DVDs use superior technology, offer better picture and sound, and have roughly 14 times the storage capacity of a VCD. A standard-length movie doesn’t even fit on one VCD, it has to be chopped up and placed on two discs. A DVD-video disc holds not only your average 90-minute feature film, it also usually contains two versions of the same movie: a panned-and-scanned (full screen) version that has been modified to fit the dimensions of your TV set, and a letterboxed (widescreen) version that preserves the screen dimensions of the original cinematic release. Aside from multiple versions of the movie, DVDs often have several different soundtracks: Dolby stereo which yields great stereo sound on standard TVs, and digital soundtracks with up to 6.1 channels of specially remixed and enhanced audio for that total home theater experience. Aside from all these, DVD-Video uses MPEG-2 video quality to MPEG-1 compression used in VCDs. It’s no wonder that serious movie fans consider DVD the ultimate format for collecting movies. DVD is taking the world by storm. Since its lunch in 1997, it has become the most successful consumer product ever, becoming an established format faster than videotape, laser disc or CD.

How to choose a Motherboard

Motherboards (alternatively, Mainboards, mobo, or planar boards) are the backbone of any computer system. Without a working or properly installed motherboard, the computer is just an inert junk of plastic. The latest motherboard technology right now is called PCIe or PCI Express. In PCIe, the shared bus is replaced with a shared switch. Each device in the system will have exclusive access to the switch, and the switch will be able to create point-to-point exclusive communications between devices.

When choosing a motherboard, it is important to carefully consider the following concepts.
Non-Integrated System Board – each major component are installed in computer as an expansion card, like video card, sound card, LAN card, etc.
Integrated System Board – most of the component that would otherwise be installed as expansion card are integrated into the motherboard circuitry and were designed for simplicity.

Selection of motherboards
Consider the following when selecting a new or replacing a motherboard:

1. The footprint, or size requirements, form factor of the computer case. Such as ATX (Advanced Technology Extended), Micro ATX, NLX (New Low Profile Extended), and BTX (Balanced Technology Extended).
2. Compatibility with other devices such as CPU/processor, power supply, memory modules, and storage devices.
3. Compatibility or type of BIOS (Binary Input Output System).
4. Memory needs of the system. The type of memory, is it DDR2 or DDR3? How much memory can the motherboard handle? How many modules can the motherboard physically hold?
5. Number of expansion slots. How many regular PCI (Peripheral Component Interconnect)? How many PCIe? Availability of an AGP (Accelerated graphics Port) if there is?
6. Number and types of ports. How many USB (Universal Serial Bus) ports at the back of the motherboard? Are there USB slots integrate on the motherboard? Availability of a Firewire, serial port, parallel port, and keyboard and mouse port?
7. What integrated peripherals are included on the motherboard? Such as Network card (LAN card), video card, or sound card.
8. Disk controllers. IDE (Integrated Device Electronics), RAID (Redundant Array of Independent Discs), or SATA (Serial Advanced Technology Attachment).
9. Are there drivers available for all the on-board components that match the operating system you want to use?
10. Is the motherboard going to be used in a media center PC? If so, are the television/cable connections available?

How to add memory to a Laptop Computer

This article walks you through adding memory to your laptop computer. Adding memory to your laptop is a very simple process and it takes about 10-15 minutes. See also How to choose the right memory for your system.

First steps:
Discharge your self to avoid any electro static charges in your body. Locate the memory cover located on the bottom of the laptop. The first thing we need to do is turn off your laptop. Once it is completely off you will need to locate the cover for the memory compartment on the bottom of your laptop. The memory cover will be a square area with one or more screws to attach a cover to the bottom of your laptop. There are usually several compartments located on the bottom of laptop computers, some labeled and some not. Generally the cover for memory is square and 3 or 4 inches long/wide.

Second steps:
Once you have located the cover of the laptop memory you will need to remove it by using a small Phillips screwdriver. After the screws are removed the cover generally pops off or swings upward depending on the model of laptop. Once you have removed the cover you will see one or more memory chips. Laptops generally have two slots for memory chips.

Third steps:
Memory retaining lever now that we have located the laptop memory and removed the cover it is time to add the memory. If both memory slots are full you may need to remove one or both memory chips to put in your new memory depending on how much memory you purchased and the size. To remove the memory from the computer you will need to locate the release levers generally located on each side of memory. You will need to gently pull the lever away from the side of the memory to release it. Once the levers are release you will be able to gently pull the memory out of the socket.

Fourth Steps:
Now that we have removed the memory we can now add the new memory to your laptop computer. To do this you will want to slide the new memory into the socket where the old memory was removed or the socket that was empty. You will need to be careful during this process as the memory only fits one way. Never force the memory into the slot. Once you have the memory in the socket you will need to gently press down toward the bottom of the laptop in order to secure the holding levers around the sides of the new memory. Now attach the memory compartment cover and start your computer.

The Different Internal DOS Command

If you are a DOS (Disk Operating System) novice just learning these commands I would recommend just scrolling down the screen and reading about them all. Just remember the important ones like: DIR, COPY, CD, RD and DEL. In programs that respond to commands through a command-line interface, the user must enter an exact command, usually in the form of a keyword, into the computer. They will get you started. Internal DOS commands are a part of the operating system and are loaded together with it. Running internal DOS commands doesn't require the presence of a system disk in a drive.

BREAK - Sets or clears extended CTRL+C checking.
CD - Displays the name of or changes the current directory.
CHDIR - Displays the name of or changes the current directory.
CLS - Clears the screen.
CMD - Starts a new instance of the Windows command interpreter.
COPY - Copies one or more files to another location.
DATE - Displays or sets the date.
DEL - Deletes one or more files.
DIR - Displays a list of files and subdirectories in a directory.
ERASE - Deletes one or more files.
EXIT - Quits the CMD.EXE program (command interpreter).
MD - Creates a directory.
MKDIR - Creates a directory.
PATH - Displays or sets a search path for executable files.
PROMPT - Changes the Windows command prompt.
RD - Removes a directory.
REN - Renames a file or files.
RENAME - Renames a file or files.
RMDIR - Removes a directory.
SET - Displays, sets, or removes Windows environment variables.
TIME - Displays or sets the system time.
TYPE - Displays the contents of a text file.
VER - Displays the Windows version.
VERIFY - Tells Windows whether to verify that your files are written correctly to a disk.
VOL - Displays a disk volume label and serial number.
LOCK - It 'locks' a disk so DOS programs can have direct access to it.
UNLOCK - This unlocks a drive from direct disk access.

That’s it guys! I hope the following internal DOS commands were helpful to you. I know there are a lot of internal DOS commands available in DOS but those commands are the only thing I remembered just notify me if some are missing in you’re lists.

What are the different parts of the Keyboard

The keyboard is the common data entry device in a computer system. It is also called the Standard Input Device. You should also note that it is the slowest of all the input devices to use. It works with the very low current to send electrical impulses to the CPU when you press a key. Because the low current there is very little risk of electric shock from a keyboard and safety precautions are not necessary when using one.

A typical keyboard is divided into 5 regions:

1. The Qwerty keyboard – This is the part of the keyboard that is used the most and gets its name from the first six letters of the top rows of the keys i.e. “Q, W, E, R, T, Y”. Note that this is only the case in the UK – other countries such as France have different key combinations reflecting their different use of letters. The layout of the keys was originally devised to actually slow typist down as the early typewriters were prone to getting jammed if the keys were hit too quickly. The average speed of a trained typist on a qwerty keyboard. Such as the shown above is up to six character per second.
2. The Function keys – this part of the keyboard is situated above the qwerty keyboard. These keys are given the symbols F1 to F12 and are really shortcut keys to operate actions in programs or in the computer’s memory system. For example, pressing the F4 key might be a shortcut to saving a document to disk in a common word processing package.
3. Editing keys – this part of the keyboard is situated to the right of the qwerty keyboard and is used to edit text or data in common programs. The edit keys are also used to move around the document (Page up or Page down) or go to the start (by depressing the Home key) or end (by depressing the end key).
4. The Cursor Control Keys – These keys represent a quick way to move the cursor (in. for example, a word processing program) and are often quicker to use than the mouse. They are not recommended for moving the cursor over large distances. Here the home, end or page up and page down keys should be used.
5. The Numeric Keyboard – this part of the keyboard is used mainly by the people in the financial services to enter large amounts of numerical data. The keys are duplicates of those above the Qwerty keyboard but are the positioned on the extreme right of the keyboard for ease of use with one hand.