Saturday, January 28, 2012

Evolution of MS-DOS "Deal of the Century"

IBM & Microsoft History


In 1980, IBM first approached Bill Gates of Microsoft, to discuss the state of home computers and what Microsoft products could do for IBM. Gates gave IBM a few ideas on what would make a great home computer, among them to have Basic written into the ROM chip. Microsoft had already produced several versions of Basic for different computer system beginning with the Altair, so Gates was more than happy to write a version for IBM.

Gary Kildall


As for an operating system (OS) for an IBM computer, since Microsoft had never written an operating system before, Gates had suggested that IBM investigate an OS called CP/M (Control Program for Microcomputers), written by Gary Kildall of Digital Research. Kindall had his Ph.D. in computers and had written the most successful operating system of the time, selling over 600,000 copies of CP/M, his operating system set the standard at that time.

The Secret Birth of MS-DOS


IBM tried to contact Gary Kildall for a meeting, executives met with Mrs Kildall who refused to sign a non-disclosure agreement. IBM soon returned to Bill Gates and gave Microsoft the contract to write a new operating system, one that would eventually wipe Gary Kildall's CP/M out of common use.

The "Microsoft Disk Operating System" or MS-DOS was based on Microsoft's purchase of QDOS, the "Quick and Dirty Operating System" written by Tim Paterson of Seattle Computer Products, for their prototype Intel 8086 based computer.

However, ironically QDOS was based (or copied from as some historians feel) on Gary Kildall's CP/M. Tim Paterson had bought a CP/M manual and used it as the basis to write his operating system in six weeks. QDOS was different enough from CP/M to be considered legally a different product. IBM had deep enough pockets in any case to probably have won an infringement case, if they had needed to protect their product. Microsoft bought the rights to QDOS for $50,000, keeping the IBM & Microsoft deal a secret from Tim Paterson and his company, Seattle Computer Products.

Deal of the Century


Bill Gates then talked IBM into letting Microsoft retain the rights, to market MS-DOS separate from the IBM PC project, Gates and Microsoft proceeded to make a fortune from the licensing of MS-DOS. In 1981, Tim Paterson quit Seattle Computer Products and found employment at Microsoft.

Sources:www.about.com

Saturday, January 7, 2012

How to Set Up an Amazon EC2 Instance

To start with Amazon Cloud we are going use the AWS Management Console. Login to the Management Console (If registered Else create an account with your credit card details and then login). On the home screen, make sure the tab EC2 is selected. then follow these steps as in images...


Now We need to select an ami so here i am going with ubuntu AMI. Here we can choose ami from amazon also in Quick start tab. But we are going with ubuntu so we will get it in community AMIs and search for your Amazon ami using AMI-ID. we can choose with or without EBS.



 Now select Instance Type, here i am going with micro instance


Now if we need to go for specific settings then we can customize but here we are going with default settings as first time.


Now Keep a name for your server as


Now We need to create a key pair & download .pem file which can be use to connect to server usingh ssh.


Now select security group which will allow us to connect/Access cloud AMI based on rules.


Now the summary of instance we have configure & chosen for Click launch to start the AMI.


Now After this step in few minute our AMI will start. Now we need to enable SSH in security group. then only we can connect to our AWS AMI as


ssh -i keypairfilename.pem ubuntu@public_address of AMI

if it ask for password provide as ubuntu further we can change it.

Friday, January 6, 2012

How to install Mac OS X Lion on Windows using VMware

Requirements
A laptop or desktop computer that supports virtualization (most newer computers do).
At least 3 GB of RAM (the more, the better. OS X Lion requires 2GB to Proceed installation).
VMWare Workstation.
VMWare Hard Drive (vmx files, it is in a self-extracting .exe file just search for Mac_OS_X_Lion_VMware_Files.exe in Google).
OS X Lion (VMDK File)

Before we start, make sure that you have enabled Virtualization in the BIOS of your computer. This is usually disabled by default by computer manufacturers.

Now follow These steps.

  1. From the file downloaded, double click on Mac OS X Lion VMware Files.exe. Click Run then Yes. This will decompress the files.

  2. Once done, a folder named Mac OS X Lion VMware Files will appear, double click it.

  3. You will need to unlock VMWare. for this As the Administrator user, run the "windows.bat" program (located in the Workstation - Windows directory) from the command line (Command Prompt). follow readme.txt for help.

  4. From Step 1, there should be a folder named Mac OS X Lion inside Mac OS X Lion VMware Files. Copy the OS X Lion (VMDK File) to this locationOpen that up and open the file named Mac OS X Lion.vmx. Double-click this file. It will open in VMWare Workstation.

  5. On the left column, click on Edit Virtual Machine Settings. In the Memory tab, you can edit how much RAM OS X will get (Minimum 2 GB). At the bottom of the box is an Add button, click it. Select Hard Disk from the left, click Next. Choose Use and existing virtual disk.

  6. Browse for the Mac OS X Lion Installer.vmdk that was downloaded from the torrent. Click Finish. Click OK to close the box.

  7. On the left column, click Power on this virtual machine.

  8. If a box asks to repair the image, click Repair. Once the box comes up, click I copied it, click OK. A message about the CD Drive may come up, just click OK.

  9. You should now have a Install Mac OS X screen. At the top, click Utilities then Disk Utility. Select the 42.45 GB Hard Disk. Click on the Erase tab. Now you can name your hard drive what you want. Then click on Erase. Click Erase again.

  10. Once the process is done, close out of the Disk Utility box, the Install screen will come back up. Click Continue, Agree. Select the 40GB Hard Disk to install Lion. Click Install. The process will take about 30 minutes. Once it's done, the account setup will start. Once that's done, Lion will start.

Now Every thing is done Just go through your settings & its all done.

Wednesday, January 4, 2012

How to delete files older than certain time in linux

The find utility on linux allows us to pass in a bunch of interesting arguments, including one to execute another command on each file. We’ll use this in order to figure out what files are older than a certain time/days, and then use the rm or delete command to delete them.

Using rm command


find /path/to/files* -mtime +5 -exec rm {} \;



Note that there are spaces between rm, {}, and \;

Explanation

  • The first argument is the path to the files. This can be a path, a directory, or a wildcard as in the example above. I would recommend using the full path, and make sure that you run the command without the exec rm to make sure you are getting the right results.

  • The second argument, -mtime, is used to specify the number of days old that the file is. If you enter +5, it will find files older than 5 days.

  • The third argument, -exec, allows you to pass in a command such as rm. The {} \; at the end is required to end the command.


Using delete command

First goto the Directory where we have to delete the files older than certain time/day.
CD /directory/path

Now Suppose we have to delete files older than 2 hour so we will use -mmin +120 which will list out all files older than 2 hours(120 min) & then delete to delete them as

Find . -mmin +120 -delete

Now Suppose we have to delete files older than 2 day so we will use -mtime +2 which will list out all files older than 2 days  & then delete to delete them as

Find . -mtime +2 -delete

here i am using  '.' after find which is showing current directory.