Raspberry Pi a credit-card sized computerThe Raspberry Pi is a credit-card sized computer that plugs into your TV and a keyboard. It’s a capable little PC which can be used for many of the things that your desktop PC does, like spreadsheets, word-processing and games. It also plays high-definition video. The Raspberry Pi is a credit-card-sized single-board computer developed in the UK by the Raspberry Pi Foundation with the intention of promoting the teaching of basic computer science in schools.
Raspberry Pi is available in two models Model A has 256MB RAM, one USB port and no Ethernet (network connection). Model B has 512MB RAM, 2 USB port and an Ethernet port.
What is the Raspberry Pi?
Initially, the Raspberry Pi was seeded out as an early developer release, with hopes of gaining early support from the development community. However, on the night of release, all distributor sites where slammed with a glut of requests. If you were lucky enough to nab one of the first units, odds are you were either amazed or utterly disappointed by what arrived in the mail.
If you were underwhelmed by the Pi, it might be that you got it for the wrong reasons. Let's be honest: the Pi is really an educational device, meant for hobbyists and aspiring youths out there to learn about programming. It's not meant to replace that powerhouse Linux desktop you built last summer with your savings.
Sporting a meager 256MB of RAM and a 700MHz ARM-11 processor, the Pi is a modest piece of kit. Keep in mind this chip's main purpose is to power a cheap computer with a basic level of functionality, mainly geared towards education. The Model B also sports two USB ports, HDMI out and a 10/100 Ethernet port. For your audio needs, you've got a 3.5mm audio jack and that HDMI output, which also supports audio transmission. The Raspberry Pi's GPU boasts 1 Gpixel/s, 1.5 Gtexel/s or 24 GFLOPs of general purpose compute power and is OpenGL 2.0 Compliant. In other words, it's got the graphics power of the original Xbox.
The Raspberry Pi measures 85.60mm x 56mm x 21mm, with a little overlap for the SD card and connectors which project over the edges. It weighs 45g, The GPU provides Open GL ES 2.0, hardware-accelerated OpenVG, and 1080p30 H.264 high-profile decode.
The GPU is capable of 1Gpixel/s, 1.5Gtexel/s or 24 GFLOPs of general purpose compute and features a bunch of texture filtering and DMA infrastructure.
That is, graphics capabilities are roughly equivalent to Xbox 1 level of performance. Overall real world performance is something like a 300MHz Pentium 2, only with much, much swankier graphics.You have to boot from SD but a USB HD can “take over” after the initial boot. You cannot boot without an SD card. How do I connect a mouse and keyboard?
Model A has one USB port and Model B has 2. Beyond this, mice, keyboards, network adapters and external storage will all connect via a USB hub.
What operating system (OS) does it use?
Its recommended Debian as default distribution. It’s straightforward to replace the root partition on the SD card with another ARM Linux distro if you want to use something else there are several available on downloads page of Raspberry pi The OS is stored on the SD card.
know more in video.
since Operating system is stored in sd card of Raspberry Pi so to start using Raspberry Pi first time we need to Install the Raspbian image to an SD Card is little hard.
There are quite a few methods for writing the Raspbian image to your SD card, regardless of whether you're using Windows, Mac OS X or Linux.
If you're using Windows
we need to download Win32DiskImager from here.Once you've done that, grab the Raspbian image from here. Choose the latest direct download of Raspbian.Once you've downloaded both Win32DiskImager and the Raspbian image, we'll need to unzip them. To keep things simple, extract everything to the desktop, or a folder located there, in easy reach. Unzip both win32diskimager-binary.zip and 2012-08-16-wheezy-raspbian.zip.
Then insert your SD card into your reader. Make note of the drive letter. After unzipping those files and connecting your card, double-click the Win32DiskImager binary to load the program.
Once you open your image, click "Write", click "Yes" to confirm the write and go grab a cup of coffee.
Now you can boot your Raspberry pi for first time with your Newly installed operating system
Booting your Pi for the first time
The first time you boot the Raspberry Pi you'll see a configuration tool called "raspi-config." (If you ever need to revisit this configuration screen again, you can always call the "raspi-config" command from the terminal of your Pi.) While you're there, you'll need to change a few options.
Highlight that "expand_rootfs" option and press Enter. You'll then see the confirmation below, at which point pressing Enter will take you back to the main raspi-config screen.
Next up is the overscan option. If you notice, the screen is not taking up the entire real estate afforded by your monitor; it's best to disable overscan so that you can utilize your monitor or television to its entirety. If your screen looks fine, though, you can skip this step. In any case, assuming you do go through with this step, select "overscan" and press Enter.
Here you get the option to disable or enable. If you ever upgrade to a new monitor or television you may need to re-enable overscan at a later point.
After that quick step, now we want to verify our keyboard settings. If you are in America you want to change this; if you're in Great Britain these are safe to leave at the standard config.
Select "configure_keyboard" and press Enter. Then you'll be presented with a very long list of keyboard options. If you know your keyboard setup, select it in the list, otherwise you'll be fine with the default 105-key option.
After selecting your keyboard type, you'll need to specify the layout. There's a good chance you want a different layout than English (UK), so choose "Other" and select the most appropriate option.
You'll then be asked about modifier keys -- just choose the default here, as well as "No compose key" on the next screen. If later you find you need a compose key to create alternative characters, you can return to this configuration screen by running "raspi-config".
The last option you'll need to set in the Keyboard configuration is the ALT / CTRL / BACKSPACE feature to kill X11. We recommend you enable this, so that in case your GUI ever crashes you can safely kill it without rebooting.
Back at the main menu, the next step is to set a user password.
Select "change_pass" and press Enter. After a confirmation screen, you'll be prompted to choose a new UNIX user password.
Almost done now. Let's set your "locale," which is the general character set used by your native language. Again, if you don't live in Great Britain, you'll want to change this to your local character set. If you're in the good ol' US of A, you want en_US.UTF-8. Scroll down to your locale of choice, and de-select the en_GB option on your way. In our case, we'll be enabling en_US.UTF-8
The next dialogue window will ask you to choose a default locale, select the locale you just chose on the previous screen and press Enter.
Back on raspi-config's main menu, set the appropriate timezone by selecting -- you guessed it -- the "change_timezone" option. You'll be presented with a list of regions first. Back at the main setup, you can safely ignore the remaining options for now and select "Finish." You'll be prompted to reboot to make changes; do so. Once your system is back online, you'll get a login prompt enter your password.
Now that you've logged in to your freshly baked Raspberry Pi, the first thing you want to do is type "startx" to get your GUI environment loaded, which from here on out we'll refer to as your Window Manager.