IT Technology

The Best University Education At the Bentley University

2013-12-08T03:58:00.002-08:00

The Best University Education At the Bentley University

http://www.youtube.com/watch?v=KqUryRLrDio&feature=youtu.be

University of Surrey UK The best for University Educations

2013-11-17T07:33:00.001-08:00

University of Surrey UK The best for University Educations

The Liberty University is the best for university educations

2013-11-15T06:42:00.001-08:00

The Liberty University is the best for university educations

The Business Education Life Style At The Babson College

2013-07-21T02:57:00.001-07:00

The Best Business Education Life Style At The Babson College

iPhone Funny Messages

2012-12-15T02:16:00.001-08:00

LG New Glasses Free 3D Display released in 2012

2012-01-31T21:56:00.000-08:00

LG announced their glasses free 3D technology display to be available to customer next year year. This new LG DX2500 glasses free 3D display monitor has been released in

South Korea

. It is available in 20 inch and 24 inch models. The best features of the LG DX2502 is the parallax barrier 3D technology and an integrated camerafor enhanced 3D experience based on your position (head-tracking). What’s more, the LG DX2500 comes equipped with the “TUV Rheinland” certification. This glasses free 3D monitor is expected to be released internationally in 2012.

iPhone 4S Battery Issue after Update iOS 5.01

2012-01-31T21:54:00.000-08:00

It seems like iOS 5.01 update did not help much in solving iPhone 4S battery issue. Although more than 40% said that iOS update fix their battery problem but for some the situation is even worse. Apple who is seriously concerned about the issue, release the iOS update iOS 5.01, but they are working hard to give a proper solution to the iPhone users.

Some analyst reported different views on this iOS update.

Michael Gartenberg said, “I’m not seeing an issue myself, except there are more features I use on a regular basis which do affect battery life. As with all devices, what features you use extensively will affect battery life.”

Michael Morgan, an ABI Research mobile device expert said. “iOS 5 may simply be using more data transmission or running more background processes to support its new features. There is also some potential impact of iCloud services.”

The analyst are of the view that it takes time for the apple to bring out better solution for the drainage of iPhone 4S battery. While users can minimize this problem by turning off Siri “raise to talk” feature, non-critical notifications, reducing data-sync services

New Model OF Sony VAIO VPCEL22FX/B Laptop

2012-01-31T21:49:00.000-08:00

Best Buy is selling the Sony VAIO VPCEL22FX/B laptop is avaialbe for $349.99 on Best Buy. Sony VAIO VPCEL22FX/B laptop features an AMD Dual-Core Processor E-450 with AMD Mobility Radeon HD 6310 graphics.

The Sony VAIO VPCEL22FX/B laptop is equipped with 4GB of memory, a 320GB hard disk, a DVD writer, a 15.6-inch LED-backlight 1366×768 screen panel, webcam, HDMI, four USB 2.0 ports, a media card reader, as well as Wi-Fi and Gigabit LAN connections. It runs Windows 7 Home Premium OS.

Source

New iPad Mini will release in March 2012

2011-12-21T22:56:00.000-08:00

There are some latest news on the release date of iPad mini. Forbes reports that iPad Mini will probably release in March 2012.

The possible delay in iPad mini is because Apple is trying to fix all loop holes before delivering the best product for its customers.

Apple is currently working on the retina display foriPad 3 and want to give their customer the tablet with great resolution – for both of their products iPad Mini and iPad 3, but definitely iPad mini is going to make this easier before the final launch of iPad 3.

latest New 3D Transistors now in IT World Coming Soon In 2012

2011-12-21T22:52:00.000-08:00

Researchers from Purdue and Harvard universities have created a new type of transistor made from a material that could replace silicon and have a 3-D structure instead of conventional flat computer chips. These new 3d transistors promising future chips, lighter laptops.

The approach could enable engineers to build faster, more compact and efficient integrated circuits and lighter laptops that generate less heat than today’s. The transistors contain tiny nanowires made not of silicon, like conventional transistors, but from a material called indium-gallium-arsenide.

The device was created using a so-called “top-down” method, which is akin to industrial processes to precisely etch and position components in transistors. Because the approach is compatible with conventional manufacturing processes, it is promising for adoption by industry, said Peide “Peter” Ye, a professor of electrical and computer engineering at Purdue.

A new generation of silicon computer chips, due to debut in 2012, will contain transistors having a vertical structure instead of a conventional flat design. However, because silicon has a limited “electron mobility” — how fast electrons flow — other materials will likely be needed soon to continue advancing transistors with this 3-D approach, Ye said.

Indium-gallium-arsenide is among several promising semiconductors being studied to replace silicon. Such semiconductors are called III-V materials because they combine elements from the third and fifth groups of the periodic table.

New Technology "Cool iPad Case with Portable Speakers"

2011-12-21T22:45:00.000-08:00

If you want a cool iPad case along with portable speaker system, then iMainGo XP can be a great buy. iMainGo XP case not only covers your precious iPad but also gives you stereo sound with 4-speaker system.

Securely fit your iPad with iMainGo XP case to ensure protection. The iMainGo XP case is great for music lovers. iMainGo XP comes with a wall charger, foldable stand, and two 3.5 mm jacks.

New Nokia X2-02 with Specifications

2011-12-21T22:26:00.000-08:00

Nokia X2-02 Features:

Nokia has announced the Nokia X2-02 mobile phone this month. It is a dual SIM mobile phone that comes with a 2.2 inch QVGA TFT display with a resolution of 240 x 320 pixels, a built in FM radio and an MP3 player.

Nokia X2-02 Specifications:

General 2G Network GSM 900 / 1800 – SIM 1 & SIM 2
Announced 2011, December
Status Coming soon
Size Dimensions 113 x 50 x 15 mm, 125.5 cc
Weight 71 g
Display Type TFT
Size 240 x 320 pixels, 2.2 inches (~182 ppi pixel density)
Sound Alert types Vibration, MP3 ringtones
Loudspeaker Yes
3.5mm jack Yes
Memory Phonebook Yes, Photocall
Call records Yes
Card slot microSD, up to 32GB
Data GPRS Class 12 (4+1/3+2/2+3/1+4 slots), 32 – 48 kbps
EDGE Class 12
3G No
WLAN No
Bluetooth Yes, v2.1 with A2DP
USB Yes, v2.0 microUSB
Camera Primary 2 MP, 1600×1200 pixels
Video Yes
Secondary No
Features Messaging SMS, MMS, Email, IM
Browser WAP 2.0/xHTML
Radio Stereo FM radio with RDS; built-in antenna, FM
Games Yes
Colors Bright Red, Dark Silver, Orange, Violet, Ocean Blue
GPS No
Java Yes, MIDP 2.1
Dual SIM
SNS applications
MP4/H.263 player
MP3/AAC+ player
Organizer
Voice memo
Predictive text input
Battery Standard battery, Li-Ion 1020mAh (BL-5C)
Stand-by Up to 443 h
Talk time Up to 9 h 50 min

What is DTE & DCE and its Definition?

2011-11-30T22:22:00.001-08:00

Definition: DTE & DCE

DTE

DTE is acronym for Data Terminal Equipment.

Examples of DTE is computers, printers & terminals.

DCE

DCE is acronym for Data Communication Equipment.

Examples of DCE is modems.

Wiring

Wiring a cable for DTE to DCE communication is easy. All wires goes straight from pin x to pin x.

But wiring a cable for DTE to DTE (null modem) or DCE to DCE requires that some wires are crossed. A signal should be wire from pin x to the opposite signal at the other end. With opposite signals I mean for example Transmit & Send.

Contributor

Source: ?

Please send any comments to

DCE equipment is typically a modem or other type of communication device. The DCE sits between the DTE (data terminal equipment) and a transmission circuit such as a phone line. Originally, the DTE was a dumb terminal or printer, but today it is a computer, or a bridge or router that interconnects local area networks. In an IBM mainframe environment, a communication controller and a link-attached cluster controller are examples of DTEs.

A DCE provides a connection for the DTE into a communication network and back again. In addition, it terminates and provides clocking for a circuit. When analog telephone lines are the communication media, the DCE is a modem. When the lines are digital, the DCE is a CSU/DSU (channel service unit/data service unit).

DTE and DCE interfaces are defined by the physical layer in the OSI (Open Systems Interconnection) model. The most common standards for DTE/DCE devices are EIA (Electronic Industries Association) RS-232-C and RS-232-D. Outside the

United States

, these standards are the same as the V.24 standard of the CCITT (Consultative Committee for International Telegraphy and Telephony). Other DTE/DCE standards include the EIA RS-366-A, as well as the CCITT X.20, X.21, and V.35 standards. The later standards are used for high-speed communication over telephone lines.

DTE and DCE devices send and receive data on separate wires that terminate at a 25-pin connector. It is useful to know that DTE devices transmit on pin connector 2 and receive on pin 3. DCE devices are just the opposite-pin 3 transmits and pin 2 receives.

Computer Hardware Tutorials

2011-11-30T22:09:00.000-08:00

Computer Hardware Tutorials

PC Computer Notes has been designed as a free introductory level, online computer training course, providing tutorials on computer hardware, software, operating systems, and basic troubleshooting.

If you just want to learn more about your computer's hardware, software and the overall system, here's a good place to start! Read the tutorials, then try the exercises provided. If you have trouble with the review questions, go over the tutorials again. You'll be surprised at how much you learn!

The computer hardware tutorials, labs and review questions may also be helpful for those preparing for Comp TIA A+ A plus Certification exams If you're looking for study material for your Comp TIA A+ A plus computer technicians exam, PC Computer notes' tutorials can be used as a source for pre-exam study.

Although the review questions may not be exactly what's on the test, they are designed to cover the information provided in the tutorials and emulate the type of questions that you'll find on the A plus exam. I do still have companies offering software for evaluation. I also have some interest from former subscribers that are interested in writing articles. So, I may make an attempt to get the News Letter back up, with perhaps a different format, if there is enough interest. Check back this summer! New subscriptions will not be accepted before that. Until then, a few of the old are still available.

My Computer

Aside from a little information on binary and hexadecimal numbers, this section deals mainly with the parts of your computer you can see at your desk.

Starting with the computer case, we'll discuss it's role concerning the actual expandability, protection, and lifetime of your system. We'll go on to include the different types, sizes, and form factors available and what you need to know before you purchase.

Next, you'll learn about some of the peripherals such as monitors, keyboards and the mouse. Different kinds, how they work, care and maintenance and possibly some simple troubleshooting methods are covered.

Before learning a little about binary and hexadecimal numbering systems, we'll look at the different ports and connectors on the back of your computer. What's a DB-9 connector? What's a Parallel Port connector? What's it used for? It's not that difficult! It just seems a little intimidating at first. Just click on the link below to start your tutorial.

Inside the computer case

Some people get a little excited when they look inside a computer and see all the different electrical components and circuit boards. All the wires, connectors and data cables inside tend to be a little intimidating. Yet, all of today's computer repairs, replacements, upgrades and installations are getting easier and easier.

A technician could spend hours (at outrageous prices) to search for a specific chip or failed solder connection that's causing a particular problem. Repairs aren't done at the chip level anymore. Everything is very modular. It's quicker, easier, and much more economical to have the technician pop in a whole new video card or motherboard.

It's still important to know some of the different components and what they do. It can give you an insight as to which particular module may need replacement, and aids in the troubleshooting process.

It may only take 5 minutes to replace a particular FRU (Field Replaceable Unit), but it might require a lot more time to troubleshoot the problem and discover which module needs replacement.

Even if you don't plan on becoming A+ (A Plus) Certified, if you've come this far you must have an interest in computers. This is a great place to learn about what's inside that case.

Start this section with ESD (Electrostatic Discharge) precautions and work your way through in order. Once you understand ESD and the precautions you should take, go ahead and open the case. See if you can find the different components, connectors, and devices discussed. When you do, try and discover everything you can about it. What kind of chip is it? What does it do? What kind of socket does it fit into? How much data can it move at once? How fast is it?

If you have room on your desk, you can run your computer with the cover off * so you can look inside as you read (keep your hands out).

*Note: Only run your system with the cover off for a short period of time. Contrary to popular belief, leaving the cover off can interrupt the airflow, actually contributing to overheating in some cases. For short periods of time it should be OK. In fact, its often necessary when troubleshooting hardware. Its also a good time to make sure the CPU fan is working properly!

By the time you're done, you'll be removing and reinstalling some of the devices inside.

Look around for an old 286 or 386 computer. They can be picked up for less than 50 dollars, in working condition. Whether it's working, or not, you can learn an awful lot by taking it apart and putting it back together

Operating System

The Operating System (OS) is an integral part of your computer. It acts as an interpreter between the different application software programs and your computer. The OS can understand the data, information and commands used by different programs because those programs are written or coded specifically for that Operating System's interface, using it's standard rules, commands and protocols. It then translates the many commands and information into procedures the computer can understand. Computers are not of much use without an operating system.

Just a quick note on Operating Systems. As I said before, your computer will not work without one. The accepted practice in most stores is to sell computers with operating systems.

Recently, I was buying a computer for a customer and one particular store had prices considerably lower than others. Of course, there were the usual price cutting features, smaller hard drive, cheaper video card, less RAM, etc..., but it would serve the purpose. They offered the choice of Windows98 or 2000, which was really nice of them... considering the fact that you had to buy it off the shelf!

If you wanted an Operating System with your computer, it was going to cost you extra!
Make sure of what you're getting

Tips & Tricks

Tips & Tricks can often be an interesting, fun and fast way of learning a particular software. As far as understanding the computer and its operating system, everybody is at a different level. And everyone is always learning. There's so many different ways of performing the same function in a single operating system that its impossible to know them all. The OS has become so huge and intricate that even a person considered an expert couldn't possibly be aware of all the capabilities of today's Operating Systems (let alone the thousands of applications out there).

Many of the Tips & Tricks presented on this Site may be fairly basic, but as I said before, everyone is at a different level. Other tips may not be so common. I'll continue to add them when I have time or as they come up.

The Tips & Tricks found on this site are gathered from experience, magazine articles, e-zincs, other websites and reader submission. If you have a favorite that you'd like to share with other readers, please send it to us.

Network Services

In this lecture we study computer networks.

We use a top-down approach, starting with applications. We present an overall picture, which will enable you to understand the layered model of networking software. Then in the following chapters, we will study the various components (called “layers”), one by one.

What are computer networks used for ?

Computer networks allow people and machines to communicate, using a number of services. The slide shows a small subset of services.

Network Infrastructure

A computer network is made of two distinct subsets of components- distributed applications are programs running on interconnected computers; a web server, a remote login server, an e-mail exchanger are examples. This is the visible part of what people call “the Internet”. In this lecture we will study the simplest aspects of distributed applications. More sophisticated aspects are the object of lectures called “Distributed Systems” and

“Information Systems” the network infrastructure is the collection of systems which are required for the interconnection of computers running the distributed applications. It is the main focus of this lecture.

The network infrastructure problem has itself two aspects distance: interconnect remote systems that are too far apart for a direct cable connection meshing: interconnect systems together; even in the case of systems close to each other, it is not possible in non-trivial cases to put cables from all systems to all systems (combinatorial explosion, cable salad management problems etc.).The distance problem is solved by using a network, such as the telephone network with modems (see later). The meshing problem was originally solved easily because the terminals were not able to communicate with each other, but always has to go through a main computer. The mesh in such cases is reduced to a star network. Today this is solved by a complex set of bridges and routers.

(Physical Layer & Data Link Layer)

The objective of this and the following slides is to introduce the concept of layers. Like any complex computer system, a network is made of components. This decomposition is, to a large extent, stable: computer networking people have agreed on a reasonable way to divide the set of functions into what is called “layers”.

We use the term layer because the decomposition always assumes that different components can be ordered such that one component interfaces only with two adjacent components. We call “layers” the components. We start with the simplest, and the oldest network example: it is a mainframe connected to terminals. In this case, there are mainly two functions

• physical layer: translates bits into electromagnetic waves;

• data link layer: translates frames into bits.

These two functions are implemented on cables or on radio links. The physical layer has to do with signal processing and coding; it is the object of the lecture called “Telecommunications”. The data link layer has to do with bits and bytes; we will study the data link layer in this lecture.

What is a Network

Modern networks have more than the physical and the data link layers. The network layer is a set of mechanisms that can be used to send packets from one computer to another in the world. There are two types of networks: With packet switching, data packets can be carried together on the same link. They are differentiated by addressing information. Packet switching is the basis for all data networks today, including the Internet, public data networks such as Frame Relay or X.25, and even ATM. Packet switches have queues. Circuit switching is the way telephone networks operate. A circuit emulates the physical signals of a direct end-to-end cable. When computers are connected by a circuit switched network, they establish a direct data link over the circuit. This is used today for modem access to a data network. Modern circuit switches are based on byte multiplexing and are thus similar to packet switches, with the main difference that they perform non-statistical multiplexing.

A network has intermediate systems (ISs): those are systems that send data to next ISs or to the destination. Using interconnected ISs saves cable and bandwidth. Intermediate systems are known under various terms depending on the context: routers (TCP/IP, AppleTalk,…), switches (X.25, Frame Relay, ATM, telephone), communication controllers (SNA), network nodes (APPN)

Rommon recovery for cisco 3620 router?

2011-11-30T22:03:00.000-08:00

Best Answer - In 10 Steps

I'm assuming that you're looking for password recovery instructions. On just about every modern Cisco router, the process goes something like:

1. Reboot router.
2. When ROMMON is loading, send break signal on console port.
3. confreg 0x2142
4. reset
5. enable, copy start run
6. ***interfaces will be shut down!! make sure you 'no shut' them***
7. conf t, change enable secret, line con/vty/aux passwords, usernames, etc.
8. config-register 0x2102
9. ^Z, write / copy run start
10. reload, and make sure it's happy

How to setup the VEONIC CCTV Network DVR online remote viewing

2011-11-30T21:56:00.000-08:00

How to setup Modem Router ?

1) After streamyx is on

2) install modem DLINK DSL-504T router c/w dynamic DNS

3) Standard Router modem ip address : 192.168.1.1

4) username : admin / password : admin

5) WAN : Account name : veonic1@streamyx.com Password : tm2006

Connection Type : PPPoe LLC

6) make sure router is online

7) Port forwarding : to the cctv computer ip address ( 192.168.1.5)

8) Customized Rules for port forwarding.

8) DMZ : 192.168.1.5

VPON NETWORK DVR SETUP :

1 Connecting to the network

Connect an Ethernet-capable computer to the DVR LAN port using an RJ-45 crossed UTP cable or connect both of the PC and DVR to a same hub :

1. The default IP address for the DVR is 192.168.10.10. Set your PC IP address to 192.168.10.xxx (where xxx is a value between 0 ~ 254). Set the subnet mask to 255.255.255.0.

2. Reboot the PC.

3. Use IE Web browser version 6.0 SP2 up to access http://192.168.10.10. The login dialog box will appear. If you have previously changed the administration login or password, enter the login name and password you previously set. Otherwise, enter the default login name “webmonitor” and the password “oyo” then click OK.

4. For first time accessing DVR , you will be prompted to install Live Video ActiveX. Download and run the file to install ActiveX. Then restart IE browser, you will be able to see the videos. If you choose not to install Active X, you can view videos from the DVR by clicking on the View Video without Plugins link at the bottom of the page. At the prompt, enter the same administrator login name and password as before. This uses a Java applet to display the video.

In The IT World " The Necessity and Applications of Cloud Computing"

2011-10-28T23:23:00.000-07:00

The Necessity and Applications of Cloud Computing

Cloud computing owes its success to two very important factors, viz. money and convenience. The network makes it very easy to store, access and even edit every bit of your data. You won’t need to install anything on your device and best of all; every program you use will be automatically updated. You are also free from having to go through any protocol when accessing your data. This is one of the biggest reasons for the popularity of cloud computing among individual and corporate users alike. The amount of money saved with cloud computing is enormous. You only pay the service provider for the storage and access to your data, thus saving money that goes into maintaining your own storage, backup and power bills. Cloud computing also helps corporates cut down on their carbon footprint while giving them high speed access to their data at affordable prices.

Cloud computing has several applications. You must have heard of private cloud computing, which is nothing but a cloud computing network that can be accessed by only a private group of computers. Amazon and Google have both set-ups their own cloud computing services for use by individuals. Cloud computing is finding resonance with more and more users as the network can be used to share not just information but also many services.

Advantages And Disadvantages of Cloud Computing

2011-10-28T23:16:00.000-07:00

Advantages of Cloud Computing

· Cost Reduction: A cloud does away with the need for each user to put money in softwares or stand-alone servers that need a large start-up capital but are usually inadequately-utilized most of the time. With fast-paced technological innovations the norm today, these resources become outdated soon and need to be replaced for the best working efficiency. Cloud computing dispenses with the need for such repeated investments.

· Speed and Scalability: Companies no longer need to invest time and money in buying and installing the hardware, software and other applications necessary for the operation. Instead, they can simply scale-up or scale-down their usage of the network’s services as per their needs.

· Innovation: With the burden of managing resources off their backs, companies can concentrate on innovations that will make them more competitive. This helps in faster development, evaluation and final validation of their products and services.

· Location Freedom: Providers of the service can build their infrastructure in places with lower overhead costs and pass on the savings to their customers.

· Convenience: The only thing needed by a company to use this service is high-speed internet connectivity. The need for specialised equipment or personnel is completely eliminated. Billing is on actual consumption basis only while it’s also itemised to help the customer check costs.

· Flexibility: Users can withdraw their subscription at their will which gives a fair degree of operational flexibility. The services are provided under level agreements which ensure that the service provider is penalised for any lapse in service. The cloud network can also be accessed from any device with internet connectivity.

Disadvantages of Cloud Computing

· Dependence on Network Connectivity: This is the most glaring disadvantage as access to the network can be completely frozen if network connectivity is hampered. A slow network will also bottleneck the work output of cloud users.

· Legal Ownership of Information: Every service provider will have its own terms and conditions regarding the data stored on its server farms. Proper reading and understanding of the fine print is necessary as this often contains information on issues like data theft, server and backup failure, distribution rights and rules which if breached might prevent data access to a user.

· Cost: Cloud computing is financially quite viable in the long term. However, its cost is nowhere near cheap or affordable if you are setting it up on a smaller scale. There’s still a long way to go before cloud computing becomes a good and affordable solution for small-scale users.

Latest New Technology 2011 "Motorola’s Xoom"

2011-10-28T23:10:00.000-07:00

One of these being Motorola Mobility’s XOOM, which is the first tablet to operate on Google’s hotly anticipated Android 3.0 Honeycomb system. Released in February of this year the tablet boasts a two mega pixel front-facing camera for video chatting over the internet, as well as a back facing five mega pixel camera. It also has a 10.1 inch HD display screen, meaning you can enjoy watching HD movies and programs on this thin, light, and very sleek looking tablet. The main advantage the Motorola XOOM has over its competitors is that it offers a much higher resolution and larger display then most.

Of course tablets cannot be mentioned without speaking of the Apple iPad 2. Apple have updated their first version of the tablet to create a thinner design with faster specs. It features the new dual core A5 processor, this means that the iPad2 has graphics on par with a full laptop. It also boasts a front and rear facing camera as well as a longer lasting battery which can last up to ten hours.

Despite the dominance of the tablet in new technology 2011 thus far other gadgets have also shone a bright light. 3D has been a hit for a while now but Toshiba scored massive points by developing huge 3D televisions that don’t need specific glasses to view. 3D TV’s without the need of glasses were invented at the end of last year however only on small scale sets, not 65 inch televisions like Toshiba offer.

Password Recovery Procedure for the Cisco 3600 and 3800 Series Routers

2011-09-05T22:20:00.000-07:00

Introduction

This document describes how to recover the enable password and the enable secret passwords. These passwords protect access to privileged EXEC and configuration modes. The enable password password can be recovered, but the enable secret password is encrypted and must be replaced with a new password. Use the procedure described in this document in order to replace the enable secret password.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

The information in this document is based on these hardware versions:

Cisco 3600 Series Router
Cisco 3800 Series Router

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Related Products

Refer to Password Recovery Procedures for information on how to recover passwords for related products.

Conventions

Refer to Cisco Technical Tips Conventions for information on document conventions.

Step-by-Step Procedure

Follow these steps in order to recover your password:

Attach a terminal or PC with terminal emulation to the console port of the router.

Use these terminal settings:

9600 baud rate
No parity
8 data bits
1 stop bit
No flow control

Refer to these documents for information on how to cable and connect a terminal to the console port or the AUX port:

Cabling Guide for Console and AUX Ports
Connecting a Terminal to the Console Port on Catalyst Switches
Connect a Terminal to Catalyst 2948G-L3, 4908G-L3, and 4840G Series Switches

If you can access the router, type show version at the prompt, and record the configuration register setting.

Note: The configuration register is usually set to 0x2102 or 0x102. If you can no longer access the router (because of a lost login or TACACS password), you can safely assume that your configuration register is set to 0x2102.

Use the power switch in order to turn off the router, and then turn the router back on.

Important Notes:

In order to simulate this step on a Cisco 6400, pull out and then plug in the Node Route Processor (NRP) or Node Switch Processor (NSP) card.
In order to simulate this step on a Cisco 6x00 with NI-2, pull out and then plug in the NI-2 card.

Press Break on the terminal keyboard within 60 seconds of power up in order to put the router into ROMMON.

If the break sequence does not work, refer to Standard Break Key Sequence Combinations During Password Recovery for other key combinations.

Type confreg 0x2142 at the rommon 1> prompt in order to boot from Flash.

This step bypasses the startup configuration where the passwords are stored.

Type reset at the rommon 2> prompt.

The router reboots, but ignores the saved configuration.

Type no after each setup question, or press Ctrl-C in order to skip the initial setup procedure.
Type enable at the Router> prompt.

You are in enable mode and should see the Router# prompt.

Type configure memory or copy startup-config running-config in order to copy the nonvolatile RAM (NVRAM) into memory.

Important: Do not type copy running-config startup-config or write. These commands erase your startup configuration.

Type show running-config.

The show running-config command shows the configuration of the router. In this configuration, the shutdown command appears under all interfaces, which indicates all interfaces are currently shut down. In addition, the passwords (enable password, enable secret, vty, console passwords) are in either an encrypted or unencrypted format. You can reuse unencrypted passwords. You must change encrypted passwords to a new password.

Type configure terminal.

The hostname(config)# prompt appears.

Type enable secret <password> in order to change the enable secret password. For example:

13. hostname(config)#enable secret cisco

14.

Issue the no shutdown command on every interface that you use.

If you issue a show ip interface brief command, every interface that you want to use should display up up.

Type config-register <configuration_register_setting>. Where configuration_register_setting is either the value you recorded in step 2 or 0x2102 . For example:

17. hostname(config)#config-register 0x2102

18.

Press Ctrl-z or end in order to leave the configuration mode.

The hostname# prompt appears.

Type write memory or copy running-config startup-config in order to commit the changes.

Example of Password Recovery Procedure for the Cisco 3600 and 3800 Series Routers

2011-09-05T22:17:00.000-07:00

This section provides an example of the password recovery procedure. This example was created with a Cisco 2600 Series Router. Even if you do not use a Cisco 2600 Series Router, this output provides an example of what you should experience on your product.

Router>enable

Password:

% Bad secrets

Router>show version

Cisco Internetwork Operating System Software

IOS (tm) C2600 Software (C2600-IS-M), Version 12.0(7)T, RELEASE SOFTWARE (fc2)

Compiled Tue 07-Dec-99 02:21 by phanguye

Image text-base: 0x80008088, data-base: 0x80C524F8

ROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)

Router uptime is 3 minutes

System returned to ROM by abort at PC 0x802D0B60

System image file is "flash:c2600-is-mz.120-7.T"

cisco 2611 (MPC860) processor (revision 0x202) with 26624K/6144K bytes of memory.

Processor board ID JAB031202NK (3878188963)

M860 processor: part number 0, mask 49

Bridging software.

X.25 software, Version 3.0.0.

Basic Rate ISDN software, Version 1.1.

2 Ethernet/IEEE 802.3 interface(s)

2 Serial(sync/async) network interface(s)

1 ISDN Basic Rate interface(s)

32K bytes of non-volatile configuration memory.

8192K bytes of processor board System flash partition 1 (Read/Write)

8192K bytes of processor board System flash partition 2 (Read/Write)

Configuration register is 0x2102

Router>

!--- The router was just powercycled, and during bootup a

!--- break sequence was sent to the router.

*** System received an abort due to Break Key ***

signal= 0x3, code= 0x500, context= 0x813ac158

PC = 0x802d0b60, Vector = 0x500, SP = 0x80006030

rommon 1 > confreg 0x2142

You must reset or power cycle for new config to take effect

rommon 2 > reset

System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)

TAC:Home:SW:IOS:Specials for info

C2600 platform with 32768 Kbytes of main memory

program load complete, entry point: 0x80008000, size: 0x6fdb4c

Self decompressing the image : ###############################

##############################################################

############################### [OK]

Restricted Rights Legend

Use, duplication, or disclosure by the Government is

subject to restrictions as set forth in subparagraph

Rights clause at FAR sec. 52.227-19 and subparagraph

Software clause at DFARS sec. 252.227-7013.

cisco Systems, Inc.

170 West Tasman Drive

San Jose, California 95134-1706

Cisco Internetwork Operating System Software

IOS (tm) C2600 Software (C2600-IS-M), Version 12.0(7)T, RELEASE SOFTWARE (fc2)

Compiled Tue 07-Dec-99 02:21 by phanguye

Image text-base: 0x80008088, data-base: 0x80C524F8

cisco 2611 (MPC860) processor (revision 0x202) with 26624K/6144K bytes of memory.

Processor board ID JAB031202NK (3878188963)

M860 processor: part number 0, mask 49

Bridging software.

X.25 software, Version 3.0.0.

Basic Rate ISDN software, Version 1.1.

2 Ethernet/IEEE 802.3 interface(s)

2 Serial(sync/async) network interface(s)

1 ISDN Basic Rate interface(s)

32K bytes of non-volatile configuration memory.

8192K bytes of processor board System flash partition 1 (Read/Write)

8192K bytes of processor board System flash partition 2 (Read/Write)

--- System Configuration Dialog ---

Would you like to enter the initial configuration dialog? [yes/no]: n

Press RETURN to get started!

00:00:19: %LINK-3-UPDOWN: Interface BRI0/0, changed state to up

00:00:19: %LINK-3-UPDOWN: Interface Ethernet0/0, changed state to up

00:00:19: %LINK-3-UPDOWN: Interface Ethernet0/1, changed state to up

00:00:19: %LINK-3-UPDOWN: Interface Serial0/0, changed state to down

00:00:19: %LINK-3-UPDOWN: Interface Serial0/1, changed state to down

00:00:20: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0/0,

changed state to down

00:00:20: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0/0,

changed state to up

Router>

00:00:20: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0/1,

changed state to up

00:00:20: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0,

changed state to down

00:00:20: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/1,

changed state to down

00:00:50: %SYS-5-RESTART: System restarted --

Cisco Internetwork Operating System Software

IOS (tm) C2600 Software (C2600-IS-M), Version 12.0(7)T, RELEASE SOFTWARE (fc2)

Compiled Tue 07-Dec-99 02:21 by phanguye

00:00:50: %LINK-5-CHANGED: Interface BRI0/0,

changed state to administratively down

00:00:52: %LINK-5-CHANGED: Interface Ethernet0/0,

changed state to administratively down

00:00:52: %LINK-5-CHANGED: Interface Serial0/0,

changed state to administratively down

00:00:52: %LINK-5-CHANGED: Interface Ethernet0/1,

changed state to administratively down

00:00:52: %LINK-5-CHANGED: Interface Serial0/1,

changed state to administratively down

00:00:53: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0/0,

changed state to down

00:00:53: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0/1,

changed state to down

Router>

Router>enable

Router#copy startup-config running-config

Destination filename [running-config]?

1324 bytes copied in 2.35 secs (662 bytes/sec)

Router#

00:01:24: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0/0:1,

changed state to down

00:01:24: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0/0:2,

changed state to down

Router#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)#enable secret < password >

Router(config)#^Z

00:01:54: %SYS-5-CONFIG_I: Configured from console by console

Router#show ip interface brief

Interface IP-Address OK? Method Status Protocol

Ethernet0/0 10.200.40.37 YES TFTP administratively down down

Serial0/0 unassigned YES TFTP administratively down down

BRI0/0 193.251.121.157 YES unset administratively down down

BRI0/0:1 unassigned YES unset administratively down down

BRI0/0:2 unassigned YES unset administratively down down

Ethernet0/1 unassigned YES TFTP administratively down down

Serial0/1 unassigned YES TFTP administratively down down

Loopback0 193.251.121.157 YES TFTP up up

Router#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)#interface Ethernet0/0

Router(config-if)#no shutdown

Router(config-if)#

00:02:14: %LINK-3-UPDOWN: Interface Ethernet0/0, changed state to up

00:02:15: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0/0,

changed state to up

Router(config-if)#interface BRI0/0

Router(config-if)#no shutdown

Router(config-if)#

00:02:26: %LINK-3-UPDOWN: Interface BRI0/0:1, changed state to down

00:02:26: %LINK-3-UPDOWN: Interface BRI0/0:2, changed state to down

00:02:26: %LINK-3-UPDOWN: Interface BRI0/0, changed state to up

00:02:115964116991: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0,

TEI 68 changed to up

Router(config-if)#^Z

Router#

00:02:35: %SYS-5-CONFIG_I: Configured from console by console

Router#copy running-config startup-config

Destination filename [startup-config]?

Building configuration...

[OK]

Router#show version

Cisco Internetwork Operating System Software

IOS (tm) C2600 Software (C2600-IS-M), Version 12.0(7)T, RELEASE SOFTWARE (fc2)

Compiled Tue 07-Dec-99 02:21 by phanguye

Image text-base: 0x80008088, data-base: 0x80C524F8

ROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)

Router uptime is 3 minutes

System returned to ROM by abort at PC 0x802D0B60

System image file is "flash:c2600-is-mz.120-7.T"

cisco 2611 (MPC860) processor (revision 0x202)

with 26624K/6144K bytes of memory.

Processor board ID JAB031202NK (3878188963)

M860 processor: part number 0, mask 49

Bridging software.

X.25 software, Version 3.0.0.

Basic Rate ISDN software, Version 1.1.

2 Ethernet/IEEE 802.3 interface(s)

2 Serial(sync/async) network interface(s)

1 ISDN Basic Rate interface(s)

32K bytes of non-volatile configuration memory.

8192K bytes of processor board System flash partition 1 (Read/Write)

8192K bytes of processor board System flash partition 2 (Read/Write)

Configuration register is 0x2142

Router#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)#config-register 0x2102

Router(config)#^Z

00:03:20: %SYS-5-CONFIG_I: Configured from console by console

Router#show version

Cisco Internetwork Operating System Software

IOS (tm) C2600 Software (C2600-IS-M), Version 12.0(7)T, RELEASE SOFTWARE (fc2)

Compiled Tue 07-Dec-99 02:21 by phanguye

Image text-base: 0x80008088, data-base: 0x80C524F8

ROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)

Router uptime is 3 minutes

System returned to ROM by abort at PC 0x802D0B60

System image file is "flash:c2600-is-mz.120-7.T"

cisco 2611 (MPC860) processor (revision 0x202)

with 26624K/6144K bytes of memory.

Processor board ID JAB031202NK (3878188963)

M860 processor: part number 0, mask 49

Bridging software.

X.25 software, Version 3.0.0.

Basic Rate ISDN software, Version 1.1.

2 Ethernet/IEEE 802.3 interface(s)

2 Serial(sync/async) network interface(s)

1 ISDN Basic Rate interface(s)

32K bytes of non-volatile configuration memory.

8192K bytes of processor board System flash partition 1 (Read/Write)

8192K bytes of processor board System flash partition 2 (Read/Write)

Configuration register is 0x2142 (will be 0x2102 at next reload)

Router#

CCTV history and Assessing the impact of CCTV

2011-08-25T22:06:00.000-07:00

History of CCTV

In 1995, the then Home Secretary, Michael Howard MP, published a document “CCTV - Looking out for you”. It emphasized that CCTV should not become “a cure looking for an illness” and stated that “too often CCTV is perceived as the 'cure' before clearly identifying the problems which it is supposed to deal with”. To illustrate these issues, the document contained two scenarios – both involving local authority proposals to install a CCTV system.

The first scenario related to one (anonymous) borough where there appeared to be a high rate of vandalism to cars, and this level of crime “was believed to be driving people from using the town centre” and it was thought that “CCTV would be the best solution”. However, research showed that “the damage was concentrated on particular days of the week” and “most commonly appeared during one period of time on those days". Further investigation showed that the higher rate of damage was “caused by market traders when they set up early in the morning” and that implementation of a “town centre CCTV would have been an expensive non-solution”.

The second case study concerned the CCTV system installed at Newcastle-upon-Tyne City Centre. Here a police superintendent explained that, prior to the installation of CCTV, a “revised style of pro-active policing” was introduced. This resulted in a decrease of crime from 13,500 incidents in 1991 to 4,500 in 1993 and the introduction of CCTV reduced crime statistics further to 2,381 offences per year. The conclusion drawn was that “the true success of CCTV” was linked “to a strategy of pro-active policing and other positive initiatives which are inextricably linked to the use of CCTV”.

The Home Office guidance then outlined the basic components of a successful installation of a CCTV system; ingredients that are repeated in the Commissioner's draft Code and ACPO's Strategy. These components, which provide a useful checklist of actions to be taken prior to purchase, involve:

· a multi-agency approach to produce a CCTV system specification that involves all stakeholders likely to have an interest in the effectiveness of the system (e.g. police, local authorities, prosecutors, car park operators, residents groups, media representatives and representatives of retailers, restauranteurs and publicans). This approach will lead to the identification of the common social problems that CCTV aims to reduce (e.g. vandalism, shoplifting, drunkenness, burglary, pick pocketing, disorderly behaviour) and to an assessment of alternative solutions that don't need a CCTV system installed (e.g. better lighting, neighbourhood watch, improved communications with police, security patrols, no tolerance to graffiti, bye-laws re drinking, barrier entry car parks).

· a clear understanding of how and why the procurement of a CCTV system would be the best solution to mitigate the impact of the identified social problems (e.g. by providing a deterrence to the targeted behaviour or evidence that can be used in Court), and how CCTV will be co-ordinated with other initiatives (e.g. policing and anti-social behaviour strategies).

· the identification of the technical requirements from the system specification. This ensures that a procured CCTV system would have the functionality to deliver measurable results in relation to the identified problems (e.g. the system operates under the required lighting conditions; cameras have the correct zoom functionality; colours are reproduced accurately; evidential issues are resolved by the correct choice of monitors, cameras or storage devices).

· a business case that specifies the outcomes or deliverables to demonstrate that the CCTV system will be (or continues to be) a cost-effective solution to the identified social problems.

· careful consideration of staffing and operational issues (e.g. management, control room procedures, staff training, disclosure procedures, subject access procedures) and public relations issues (e.g. reports to Councillors, fair processing notices; press and public liaison) to maintain public confidence in the system.

Assessing the Impact of CCTV

The 1995 guidance from the Home Office appears to have been ignored in the rush to spend the £210 million the Government made available for the capital spend on CCTV systems between 1994 and 2003. This conclusion is apparent from a Home Office Research Study (“Assessing the impact of CCTV”, Report no. 292, Feb 2005) which studied 13 CCTV systems that were installed during this period.

Although the Home Office research contained a caveat not to come to “too simplistic a conclusion” about the effectiveness of CCTV in general, there is no mistaking its central message. The research report notes that: “It would be easy to conclude from the information presented in this report that CCTV is not effective: the majority of the schemes evolved did not reduce crime and even where there was a reduction, this was mostly not due to CCTV; nor did CCTV schemes make people feel safer, much less change their behaviour”.

This rather frank statement is accompanied with pithy explanations in relation to the management and procurement of CCTV systems studied by the researchers.

“Many projects did not have clear objectives” and that the general perception was that “CCTV was a good thing”. Sometimes installation of a CCTV created “demands by neighboring towns to catch up” and the “existence of funding for CCTV created pressure to bid for it”.
“Many schemes relied too heavily on technical consultants whose work was not scrutinized, largely because no one had the qualification to question what was done”. Since “a consultant was dispensed with in many cases, planners were unable to challenge the technical sales pitch of equipment suppliers”.
“Some systems failed to engage properly with end-users, most notably the police” and this resulted in “a loss of interest in the system and a reluctance to use the evidence supplied by the cameras”.

The research also noted that “there was a lack of realism about what could be expected from CCTV” and that “in short, it was oversold – by successive governments – as the answer (indeed magic bullet)”. The researchers commented that “few seeking a share of the available funding saw it necessary to demonstrate CCTV's effectiveness” and “it was rarely obvious why CCTV was the best response to crime in particular circumstances”. There was “a tendency to put up cameras and expect impressive results, ignoring the challenge of making what is quite a complex measure work, and failing to define what exactly the CCTV system was expected to do”.

The research also noted positive items about CCTV. For example, in the 13 systems evaluated, crime had decreased in 6 areas whereas the increase in 7 areas covered by CCTV could not be attributed to the CCTV system. CCTV had less effect on impulsive crime (e.g. alcohol-related) but had a measurable effect on premeditated crime (e.g. car theft) and there was evidence to suggest that CCTV could assist where specific problems had been identified (e.g. areas where drug dealing was prevalent or which were associated with “acquisitive crime” such as theft). Fixed areas with specific problems (e.g. car-parks) were generally a CCTV success story.

The research noted that technical issues such as camera coverage, lighting and location were important to the effectiveness of the CCTV system but not if camera density had reached saturation point. Members of the public worried less about crime in the areas covered by CCTV, but “knowing that cameras were installed in the area did not necessarily lead to reinforced feelings of security among respondents”. Above all, procurement of a CCTV system which had been integrated with other crime reduction policies (and which involved police, retailers, community wardens, publicans etc) worked when installation included consideration of the components identified in the 1995 guidance.

Nokia 5250 Touch screen Mobile

2011-08-25T21:53:00.000-07:00

Nokia has announced their new entry level touch screen mobile phone, The Nokia 5250

Nokia 5250 is the latest mobile announced by Nokia, It is a entry level mobile phone with full touch screen. Its feature includes 2.8" display, expandable memory up to 16 GB, 2MP Camera and much more.

Features and Overview of Nokia 5250:

· Full Touchscreen Display

· Easy access to Music and media, through widgets on the homescreen

· Listen to up to 24 hours of non-stop music after only one charge

· Easy access to Facebook and other social networks

· Easy to access and customize homescreen

Technical Specifications of Nokia 5250:

· Symbian S60 Series

· Dimensions: 105 x 50 x 14 mm and 106 gram

· 2.8" Display

· 2 MP Camera

· 1000 mAh Battery

· Talk Time up to 8 Hours

· Stand By Time up to 450 Hours

· Internal Memory is 51 MB

· Expandable Memory up to 16 GB via micro SD Card

· 3.5 mm AV connector

· High-speed USB 2.0 (micro USB connector)

· Push email with attachments

· Full web browsing of real web pages

· Adobe FlashLite 2.0 support

· Java TM MIDP 2.0 support

· Bluetooth 2.1 EDR wireless connectivity

· Stereo FM radio

Motorola Charm

2011-07-12T02:44:00.000-07:00

Motorola Charm is a Bar Phone. weighing 110g. It′s dimensions are 98.4 x 67.2 x 11.4 . The talk-time of the phone is Up to 6 hours 45 minutes (2G) / Up to 5 hours (3G). The phone operates at frequencies of GSM 850 / 900 / 1800 / 1900 / HSDPA 1700 / 2100 Mhz. Display type is 2.8 inches, TFT capacitive touchscreen, 256K colors. This model comes with Camera of , 3.2 Mega Pixels Camera with Geo-tagging and face detection with , Digital Zoom

General Information
Brand	Motorola
Model	Charm
Weight	110 G
Form Factor	Bar
Dimensions	98.4x67.2x11.4 MM
Operating Frequency	GSM 850 / 900 / 1800 / 1900 / HSDPA 1700 / 2100 Mhz
Key Pad	Yes, Qwerty Key Pad
Touch Screen	Yes, Capacitive Touchscreen

Display Details
Display Color	2.8 inches, TFT capacitive touchscreen, 256K colors
Display Size	Motorola Charm has a display size of 320 x 240 px

Camera
Camera	Yes, 3.2 Mega Pixels Camera with Geo-tagging and face detection
Camera Res.	2048 x 1536 Pixels
Zoom	Yes, Digital Zoom
Video	Yes
Video Resolution	Yes, 24 fps
Video Player	Yes, Video Formats : MP4, WMV, H.264, H.263

Software
Games	Yes
Java	Yes, Via third party application
Browser	Yes, HTML
Operating System	Android OS, v2.1 (Eclair)

Call Records
Phone Book	Practically unlimited entries and fields, Photocall
Missed Calls	Practically unlimited
Received Calls	Practically unlimited
Dialed Calls	Practically unlimited

Battery
Stand By Time	Up to 267 hours (2G) / Up to 334 hours (3G)
Talk Time	Up to 6 hours 45 minutes (2G) / Up to 5 hours (3G)
Li-ion	1170 mAH

Memory
Internal Memory	Yes, Internal Memory : 512 MB storage
External Memory	Yes, Up to 32GB, 2GB card included
Memory Slot	Yes, Micro SD Card

Message
SMS	Yes, Threaded View
MMS	Yes
Email	Yes, Push Email

Music
Ring Tone	Vibration, MP3, Polyphonic
FM	Yes, Stereo FM radio with RDS
Music	Yes, Music Formats : MP3, eAAC+, WAV, WMA with 3.5 mm audio jack
Speaker	Yes
Headset	Yes

Data
GPRS	Yes, Class 12 (4+1/3+2/2+3/1+4 slots), 32 - 48 kbps
Bluetooth	Yes, v2.0 with A2DP
Wirless Protocol	Yes, Wi-Fi 802.11 b/g/n
Port	Yes, microUSB v2.0
Edge	Yes, Class 12
Infra Red	No
3G	HSDPA 3.6 Mbps; HSUPA 2 Mbps
Salespack	Handset, Battery, Charger, Earphone, USB Cable, User Manual, Warranty Card

Others

Colours :

Golden Bronze, Cabernet

GPS :

Yes, with A-GPS support

Sensors :

Accelerometer sensor for UI auto-rotate, Proximity sensor for auto turn-off

Display Features :

Gorilla Glass display, Touch sensitive controls, BACKTRACK touch panel, Multi-touch input method, MOTOBLUR UI v1.5 with Live Widgets

Built In Services :

Facebook, MySpace, Twitter apps, Google Maps with Street View

Instant Messaging :

Yes

Special Features :

ocial networking integration with live updates, Active noise cancellation with dedicated mic., Digital compass

Basic Function of Computer

2011-05-04T04:57:00.000-07:00

Basic Function of Computer.

A general purpose computer has four main components: the arithmetic logic unit (ALU), the control unit, the memory, and the input and output devices (collectively termed I/O).

Control unit
Arithmetic/logic unit (ALU)
Memory
Input/output (I/O)
Multitasking
Multiprocessing
Networking and the Internet

Control unit.

The control unit (often called a control system or central controller) manages the computer's various components; it reads and interprets (decodes) the program instructions, transforming them into a series of control signals which activate other parts of the computer. The control system's function is as follows—note that this is a simplified description, and some of these steps may be performed concurrently or in a different order depending on the type of CPU:

Read the code for the next instruction from the cell indicated by the program counter.

Decode the numerical code for the instruction into a set of commands or signals for each of the other systems.

Increment the program counter so it points to the next instruction.

Read whatever data the instruction requires from cells in memory (or perhaps from an input device). The location of this required data is typically stored within the instruction code.

Provide the necessary data to an ALU or register.

If the instruction requires an ALU or specialized hardware to complete, instruct the hardware to perform the requested operation.

Write the result from the ALU back to a memory location or to a register or perhaps an output device.

Jump back to step (1).

Arithmetic/logic unit (ALU).

The ALU is capable of performing two classes of operations: arithmetic and logic. The set of arithmetic operations that a particular ALU supports may be limited to

· adding

· subtracting

· might include multiplying

· dividing,

· trigonometry functions (sine, cosine, etc.)

· square roots.

Some can only operate on whole numbers (integers) whilst others use floating point to represent real numbers.

Logic operations involve Boolean logic: AND, OR, XOR and NOT. These can be useful both for creating complicated conditional statements and processing boolean logic.

Memory.

Magnetic core memory was the computer memory of choice throughout the 1960s, until it was replaced by semiconductor memory. A computer's memory can be viewed as a list of cells into which numbers can be placed or read. Each cell has a numbered "address" and can store a single number. In almost all modern computers, each memory cell is set up to store binary numbers in groups of eight bits (called a byte). Each byte is able to represent 256 different numbers (2^8 = 256); either from 0 to 255 or −128 to +127.

Input/output (I/O).

Hard disk drives are common storage devices used with computers. I/O is the means by which a computer exchanges information with the outside world Devices that provide input or output to the computer are called peripherals. On a typical personal computer, peripherals include input devices like the keyboard and mouse, and output devices such as the display and printer. Hard disk drives, floppy disk drives and optical disc drives serve as both input and output devices. Computer networking is another form of I/O.

Multitasking.

While a computer may be viewed as running one gigantic program stored in its main memory, in some systems it is necessary to give the appearance of running several programs simultaneously. This is achieved by multitasking i.e. having the computer switch rapidly between running each program in turn.

Multiprocessing.

Some computers are designed to distribute their work across several CPUs in a multiprocessing configuration, a technique once employed only in large and powerful machines such as supercomputers, mainframe computers and servers. Multiprocessor and multi-core (multiple CPUs on a single integrated circuit) personal and laptop computers are now widely available, and are being increasingly used in lower-end markets as a result.

Networking and the Internet.

Computers have been used to coordinate information between multiple locations.

Basic Computer Structure.

Logical Structure of a computer includes:

BIOS (The Basic Input Output System)

CPU (The Processor)

Memory / RAM (Temporary Storage)

Hard Disk (Permanent Storage)

Input / Output Device

Communication Channel (Eg. USB)

Bus (High Speed Internal Communication)

Other Add-on Device…

Example of a Computer Structure.

BIOS.

Basic Input Output System

Store all the parameter before the OS Load

(Example are Hard Disk Size, Memory

Speed, Turn on or turn off the build in device

such as Sound Card, USB, printer etc)

Usually stored in Flash Memory

Identify the Component - CPU.

Central Processing Unit

It is the core of a computer.

Responsible for all the calculation and part of the video.

Usually in the Speed of GHz

1G around 1,000 MHz

1M = 1Million Instruction / second

Some Expensive CPU have more build in memory (Cache

Memory / RAM Memory.

RAM – Random Access Memory

Act as a temporary Storage.

EDO > SDRAM > DDR > DDR2

All data stored in memory are volatile.(Need electricity to keep the data)

Memory Size is around 256M / 512M /1G / 2G per memory module

Basic Configuration is around 512M RAM

Hard Disk (ATA / SATA / SCSI).

Used to stored data permanently.

Different Type of Hard Disk Size (3.5”, 2.5”, 1.8”, Micro Drive)

Different Interface : ATA / SATA /SCSI (Speed : ATA < SATA < SCSI)

Different Speed (Mechanical) (4,200rpm / 5,400rpm / 7,200rpm / 10,000 rpm )

Different Build in Memory Size (2M / 8M / 16M etc)

Different Capacity (80G to 500G or even 1T)

Small Size Hard Disk are more popular as they are portable size

Main Board / Mother Board (MB).

Provide a platform to connecting all the devices. (Keyboard / Mouse / Power / CPU / Memory / Hard Disk / Floppy Disk / Display Card etc)

Many Main Board has already build in Sound Card / Network Card or even display card.

I/O Device & Interface.

ATA / SATA /SCSI (For Hard Disk)

Parallel Port or LPT Port (For Printer)

COM Port (For Modem)

RJ45 Socket (For Network)

PS/2 (For Keyboard / Mouse)

D-Sub / DVI (For Monitor)

USB (All compatible device)

Power Supply.

Power Supply Convert the A.C. Voltage to Lower D.C. Voltage which is suitable for Computer.

Power Supply can be classified by their loading (Watt).

Different type of socket for different device.

Case.

Case is used to place the main board and the power supply.

Most case have external USB connection.

Layer Technology of Computer Architecture.

OS -Level.

An Operating System is the layer between the hardware and software, as in

An Operating System is responsible for the following functions.

Device management using device drivers

Process management using processes and threads

Inter-process communication

Memory management

File systems

In addition, all operating systems come with a set of standard utilities. The utilities allow common tasks to be performed such as

being able to start and stop processes .

being able to organize the set of available applications .

organize files into sets such as directories .

view files and sets of files .

edit files.

rename, copy, delete files .

communicate between processes .

Instruction set.

An instruction set, or instruction set architecture (ISA), is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O. An ISA includes a specification of the set of opcodes (machine language), and the native commands implemented by a particular processor.

Instruction types.

Some operations available in most instruction sets include.

Data handling and Memory operations.

Set a register (a temporary "scratchpad" location in the CPU itself) to a fixed constant value move data from a memory location to a register, or vice versa. This is done to obtain the data to perform a computation on it later, or to store the result of a computation. Read and write data from hardware devices

Arithmetic and Logic.

add, subtract, multiply, or divide the values of two registers, placing the result in a register perform bitwise operations, taking the conjunction and disjunction of corresponding bits in a pair of registers, or the negation of each bit in a register compare two values in registers (for example, to see if one is less, or if they are equal)

Control flow.

branch to another location in the program and execute instructions there conditionally branch to another location if a certain condition holds indirectly branch to another location, but save the location of the next instruction as a point to return to (a call)

Complex instructions.

Some examples of "complex" instructions include:

saving many registers on the stack at once

moving large blocks of memory

complex and/or floating-point arithmetic (sine, cosine, square root, etc.)

performing an atomic test-and-set instruction

instructions that combine ALU with an operand from memory rather than a register

Microarchitecture.

In computer engineering, microarchitecture (sometimes abbreviated to µarch or uarch), also called computer organization, is the way a given instruction set architecture (ISA) is implemented on a processor. A given ISA may be implemented with different microarchitectures. Implementations might vary due to different goals of a given design or due to shifts in technology. Computer architecture is the combination of microarchitecture and instruction set design.

Microarchitectural concepts.

In general, all CPUs, single-chip microprocessors or multi-chip implementations run programs by performing the following steps:

Read an instruction and decode it

Find any associated data that is needed to process the instruction

Process the instruction

Write the results out

DLD Level.

Digital electronics represent signals by discrete bands of analog levels, rather than by a continuous range. All levels within a band represent the same signal state. Relatively small changes to the analog signal levels due to manufacturing tolerance, signal attenuation or parasitic noise do not leave the discrete envelope, and as a result are ignored by signal state sensing circuitry. A digital circuit is often constructed from small electronic circuits called logic gates that can be used to create combinational logic. Each logic gate represents a function of boolean logic. A logic gate is an arrangement of electrically controlled switches, better known as transistors.

Device Level.

In computing, input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it. The term can also be used as part of an action; to "perform I/O" is to perform an input or output operation. I/O devices are used by a person (or other system) to communicate with a computer. For instance, a keyboard or a mouse may be an input device for a computer, while monitors and printers are considered output devices for a computer. Devices for communication between computers, such as modems and network cards, typically serve for both input and output.

Solid State Physics.

Solid-state physics. is the study of rigid matter, or solids, through methods such as quantum mechanics, crystallography, electromagnetism, and metallurgy. It is the largest branch of condensed matter physics. Solid-state physics studies how the large-scale properties of solid materials result from their atomic-scale properties. Thus, solid-state physics forms the theoretical basis of materials science. It also has direct applications, for example in the technology of transistors and semiconductors.