ETCT Notes (DCE,SNA,ten future web trends)

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SNA Server


Ten Future Web Trends


Distributed Computing Enviornment

How to enable the Security Tab in Properties window

Windows XP and other new operating systems support NTFS. NTFS provides a great security level upto files. you may protect your files, directories and drives by making them private or unaccessible for other users. for this you need a security option in properties of any folder/directory/drive which is not enab;ed by default. to enable it use following simple steps:

For security settings you need drive with NTFS support. if it is FAT then convert it by using "Convert" Command. Convert Command can be used as:




1. Open My Computer
2. Select Tools>>Folder Options.
3. Select View Tab
4. In View Tab Select Advanced (If given), otherwise uncheck the "simple file sharing(Recommended)" option from the options given below in dialog box or advanced dialog box(if it is available).
5. Click OK.

Security Tab is available now and you can appy security settings.

How to make the Drive/Folder/File Private in Windows XP

Windows XP or the operating systems supporting NTFS may provide a file level security. you can make the drives, folders and files unaccessible in other accounts. For this here are some very simple steps:
1. Right Click on the Folder/Drive/File , that you want to make private.
2. Select the Properties.
3. Select the Security Tab from the dialog Box opened. (If there is no such tab then enable it by using steps given other blog entry)
4. In the security tab remove the users that you dont want to permit to see those files(Do not Remove Administrators and system Users).
5. Remove the Authenticated users also (this group contain all users(limited and simple)).
Now your folder/file/drive is private and no other user can access it.

Difference in 568A and 568B (Method to make Cross & Straight Cable)

If both the ends will have same standard then cable is "Straight Cable" otherwise it is a "Cross Cable"

Different Hardware Components

A typical personal computer consists of a case or chassis in a tower shape (desktop) and the following parts:

Motherboard

• Motherboard - It is the "body" or mainframe of the computer, through which all other components interface.
• Central processing unit (CPU) - Performs most of the calculations which enable a computer to function, sometimes referred to as the "backbone or brain" of the computer.
• Computer fan - Used to lower the temperature of the computer; a fan is almost always attached to the CPU, and to the back of the case, also known as the 'muffin fan'.
• Firmware is system specific read only memory.
• Internal Buses - Connections to various internal components.
• Current/ Available
• PCI (being phased out for graphic cards but still used for other uses)
• PCI Express (PCI-E)
• USB
• FireWire
• HyperTransport
• Intel QuickPath (expected in 2008)
• Obsolete
• AGP (Obsolete graphic card bus)
• ISA (obsolete in PCs, but still used in industrial computers)
• VLB VESA Local Bus (outdated)
• External Bus Controllers - used to connect to external peripherals, such as printers and input devices. These ports may also be based upon expansion cards, attached to the internal buses.

Power supply

A case control, and (usually) a cooling fan, and supplies power to run the rest of the computer, the most common types of power supplies are mechanic shed (old) but the standard for PCs actually are ATX and Micro ATX.

Video display controller

Produces the output for the visual display unit. This will either be built into the motherboard or attached in its own separate slot (PCI, PCI-E, PCI-E 2.0, or AGP), in the form of a graphics card.

Removable media devices

• CD (compact disc) - the most common type of removable media, inexpensive but has a short life-span.
• CD-ROM Drive - a device used for reading data from a CD.
• CD Writer - a device used for both reading and writing data to and from a CD.
• DVD (digital versatile disc) - a popular type of removable media that is the same dimensions as a CD but stores up to 6 times as much information. It is the most common way of transferring digital video.
• DVD-ROM Drive - a device used for reading data from a DVD.
• DVD Writer - a device used for both reading and writing data to and from a DVD.
• DVD-RAM Drive - a device used for rapid writing and reading of data from a special type of DVD.
• Blu-ray - a high-density optical disc format for the storage of digital information, including high-definition video.
• BD-ROM Drive - a device used for reading data from a Blu-ray disc.
• BD Writer - a device used for both reading and writing data to and from a Blu-ray disc.
• HD DVD - a high-density optical disc format and successor to the standard DVD. It was a discontinued competitor to the Blu-ray format.
• Floppy disk - an outdated storage device consisting of a thin disk of a flexible magnetic storage medium. Used today mainly for loading RAID drivers.
• Zip drive - an outdated medium-capacity removable disk storage system, first introduced by Iomega in 1994.
• USB flash drive - a flash memory data storage device integrated with a USB interface, typically small, lightweight, removable, and rewritable.
• Tape drive - a device that reads and writes data on a magnetic tape, used for long term storage.

Internal storage

Hardware that keeps data inside the computer for later use and remains persistent even when the computer has no power.

• Hard disk - for medium-term storage of data.
• Solid-state drive - a device similar to hard disk, but containing no moving parts and stores data in a digital format.
• RAID array controller - a device to manage several hard disks, to achieve performance or reliability improvement in what is called a RAID array.

Sound card

Enables the computer to output sound to audio devices, as well as accept input from a microphone. Most modern computers have sound cards built-in to the motherboard, though it is common for a user to install a separate sound card as an upgrade. Most sound cards, either built-in or added, have surround sound capabilities.

Networking

Connects the computer to the Internet and/or other computers.

• Modem - for dial-up connections or sending digital faxes. (outdated)
• Network card - for DSL/Cable internet, and/or connecting to other computers, using the Ethernet cord.
• Direct Cable Connection - Use of a null modem, connecting two computers together using their serial ports or a Laplink Cable, connecting two computers together with their parallel ports.

Other peripherals

In addition, hardware devices can include external components of a computer system. The following are either standard or very common.

Includes various input and output devices, usually external to the computer system

Input

• Text input devices
• Keyboard - a device to input text and characters by depressing buttons (referred to as keys), similar to a typewriter. The most common English-language key layout is the QWERTY layout.
• Pointing devices
• Mouse - a pointing device that detects two dimensional motion relative to its supporting surface.
• Optical Mouse - a newer technology that uses lasers, or more commonly LEDs to track the surface under the mouse to determine motion of the mouse, to be translated into mouse movements on the screen.
• Trackball - a pointing device consisting of an exposed protruding ball housed in a socket that detects rotation about two axes.

• Gaming devices
• Joystick - a general control device that consists of a handheld stick that pivots around one end, to detect angles in two or three dimensions.
• Gamepad - a general handheld game controller that relies on the digits (especially thumbs) to provide input.
• Game controller - a specific type of controller specialized for certain gaming purposes.
• Image, Video input devices
• Image scanner - a device that provides input by analyzing images, printed text, handwriting, or an object.
• Webcam - a low resolution video camera used to provide visual input that can be easily transferred over the internet.
• Audio input devices
• Microphone - an acoustic sensor that provides input by converting sound into electrical signals

Output

• Image, Video output devices
• Printer: A Device to take Print of a file on Paper. It may be categorize as:
• Impact Printer: These Printer Uses a striking head to print characters.
• Dot Matrix
• Daisy Wheel
• Non Impact Printer: In place of striking head, some ink firing are toner technique is used:
• Ink Jet Printers
• Laser Printers
• Monitor
• Cathode Ray Tube Monitors (CRT)
• Thin Film Transistor Display (TFT)
• Liquid Crystal Display (LCD)
• Audio output devices
• Speakers
• Headset