The Hindu : Business : Bochs: An open source virtual PC software

Online edition of India's National Newspaper
Monday, Jun 07, 2004

Business

Business

Bochs: An open source virtual PC software

THIS EDITION of NetSpeak explores the features of a hardware emulation software that lets you run a virtual PC inside your real PC.

Your PC can host more than one operating system and as several free operating systems are available on the Net, you would naturally like to try out some of them. But to install more than one OS, you have to do tasks such as hard disk shrinking, partitioning, formatting and the like.

Even if you have the necessary skills, you may be reluctant to do all those tasks. One solution is to enlist the service of a virtual PC software that creates a software-based PC inside your physical PC. A virtual PC has all the components available on the real PC. The emulation software generates a virtual PC with virtual BIOS, virtual hard disk, virtual floppy disk and so on.

Once you have a virtual PC running on your machine, you can install any OS you like on it. In fact, you can run multiple virtual PC sessions with multiple operating systems on your machine. The beauty of this concept is that it enables you to run any OS you like without your having to reboot the machine each time. When you start a virtual PC, it will start the booting process just like a real PC. With this introduction, let us see the operational details of a PC-emulation software called Bochs.

Bochs (pronounced as `box') is an open-source, free PC emulation software that emulates Intel x86 machines. It creates a software-based stand alone virtual PC, which has its own memory, hard disk, display adapter and CD drive. The program, available for multiple platforms such as Linux and Windows, can be downloaded from: http://bochs.sourceforge.net/.

Download bochs and install it on your machine. Move to the Bochs directory (normally it is `c:\progra\bochs-2.1.1.' Now create a directory (say `newos'), where you will be putting all the files related to the OS you want to run on your virtual PC. Copy the model configuration file `bochsrc-sample.txt' on to this directory as `bochsrc.txt.'

The storage devices (hard disk, floppy disks) of a bochs simulated virtual PC are nothing but files on the real hard disk. So, to create a bootable file for the floppy (this will act as your boot floppy/drive), you have to generate a disk image file of the bootable floppy. For this, you can use the program WinImage, available at: http://www.winimage.com/download.htm.

Create a bootable disk (if you do not have one already) and place it on the drive. Invoke the `WinImage' program, select the option `Read Disk' (available under the menu `Disk').

Now, save the current file (say, as `a.ima,' using the option File/'Save As') on to the directory `newos.' Now, edit the configuration file (bochsrc.txt), mentioned above, so that it reflects your requirements. Load the file in an editor (like Notepad), move towards the part labelled `FLOPPYA,' insert this line: `floppya: 1_44=a.ima, status=inserted.'

If you have a CD drive and want to connect this to the simulated machine, move to the section with `ATA..' commands and insert this command: `ata0-slave: type=cdrom, path=E:, status=inserted.'

The set up is ready for a PC with bootable floppy and a CD drive. To start the simulated machine with DOS, place the CD on your CD drive and invoke the command `..\bochs' (here, we assume that you are in the `newos' directory).

If everything went fine, you will see your virtual PC coming up. The booting process will be like a real PC booting and after a few seconds you will get the usual DOS prompt `A:{gt}'. One drawback of the virtual PC is that the simulated machine will be quite slow unless you have a powerful host PC.

If you want to attach a hard disk also on to your virtual PC, first you have to create a disk image for the hard disk. For this, you can use the program `bximage' that comes along with bochs.

Run the program `bximage' and provide the required inputs. If you want to create a HD of size 500 MB, type '500', when it asks for the size. Note down such details as `cyls,' `heads' and so on, then give a name to the image file (say, `c.img'). At this point the program will display a line that starts `ata0-master ... .' Write down this line, insert it into the configuration file and run bochs again.

So, now you have a virtual PC with CD drive and HD support. But the hard disk is just a raw one. You have to partition it with `Fdisk' command, if you want to use it. If you are familiar with `fdisk' command you may proceed further, else leave it.

If you do not want to go through any of the set-up processes explained above and still want to test the concept of an OS running on a virtual PC, run the `Linux Demo' that comes along with the Bochs pack. The configuration and other files for this demo are stored in the sub-directory `DlxLinux.' In fact this is another easy way to test the features of Linux on a Windows PC.

New Yahoo toolbar

Search services such as Yahoo and Google provide toolbars that get attached to your browser so that their services can be accessed directly from the browser. Yahoo has released the latest version of its toolbar with anti-spyware support. Spyware is a program that gets installed on your machine (without your permission) for monitoring your computing/Net habits. The toolbar's anti-spyware feature can be used to find/remove spyware and other junk programs. The beta version of this Windows tool that works with IE 5 or greater can be downloaded from: http://beta.toolbar.yahoo.com/

Net on a bike

We are familiar with the scenario of a postman cycling to our village for delivering mails. Instead of mails, one person is delivering e-mails by providing people access to the Net with his Wi-Fi enabled bicycle (http://www.magicbike.net/about.html).

Read this amusing story at: http:// news.bbc.co.uk/2/hi/technology/ 3726347.stm.

J. Murali

Email the author at:

murali27@satyam.net.in

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