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Raspberry Pi: Cheat Sheet

Get to grips with one of the world's cheapest computers...
Written by Nick Heath, Contributor

Get to grips with one of the world's cheapest computers...

Mmm, Raspberry Pie
Mmm indeed. However we're not talking about drool-inducing baked goods here. When it goes on sale, the Raspberry Pi will be one of the cheapest computers ever sold.

How cheap is cheap exactly?
Roughly $25. At least that's the sort of price the Raspberry Pi's makers say they are aiming for when the Linux-based machine is released later this year.

So what is Raspberry Pi?
Raspberry Pi is about as basic as a computer gets. The device is nothing more than a circuit board with ports to connect it to a TV or monitor, a port for a power adapter and a USB 2.0 hub to hook up a keyboard or another peripheral. That's it. All told, the device is small enough to fit into the palm of your hand.

Raspberry Pi computer

A Raspberry Pi prototype attached to a 12-megapixel camera modulePhoto: Raspberry Pi Foundation

It can't be much cop if it's the same price as a taxi ride home
Well it's not a quad-core beast of a machine but it's not necessarily a slouch either. Raspberry Pi's makers estimate it's about as powerful as the average home PC of 2002 - putting it on a par with a Pentium II 266 machine. The machine has already been demoed pulling off some pretty muscular feats of computing, such as streaming high-definition video without a hitch and playing the lightning-fast first-person shooter Quake III at 1080p.

If you want to get technical, the Raspberry Pi is based around the Broadcom BCM2835 system-on-a-chip, which includes a 700MHz ARM11 chip and a graphics processing unit. The Raspberry Pi runs various distributions of the open-source operating system Linux - namely ArchLinux, Debian and Fedora. There will be two models of the Raspberry Pi, model A and model B. Model A will cost about $25 and model B $35. Model A will ship with 128MB of SDRAM, while model B will have 256MB of SDRAM. A USB wi-fi dongle can be added to support wireless networking and model B will include an Ethernet controller. Raspberry Pi connects to TVs and monitors via a composite or HDMI.

So what can I do with Raspberry Pi?
That's up to you. You could hook it up to a TV and use it as an ultra-low-cost PC for browsing the web and word processing - taking advantage of the host of free software available for Linux.

If you were feeling more ambitious, the Raspberry Pi could also make a very affordable media streamer - allowing you to stream video and music from the internet or from your other computers to your TV. Using the Raspberry Pi as a media streamer could be very easy, as developers of the popular open-source media centre software XBMC are already playing with a Raspberry Pi board.

What about something a bit more adventurous?
Controlling robots good enough for you? Robot builders are already discussing online how the device could be used to control robots by adding peripherals such as a servo controller and camera to the device, with the Raspberry Pi expected to be particularly strong at carrying out machine vision tasks. Ham radio and aerospace operators have also expressed an interest in using the Raspberry Pi.

The Raspberry Pi should be suited to a wide range of uses thanks to the hackability of its Linux OS and the board itself, which should allow users to tinker to get Raspberry Pi to work with many different external devices. The device makers, the Cambridge-based Raspberry Pi Foundation, is even planning to release the schematics and board designs for the Raspberry Pi, although the foundation's director Eben Upton has cautioned that the architecture of the device will make it very difficult for people to build the devices themselves.

How did the idea for the Raspberry Pi come about?
The Raspberry Pi is all about...

...getting children excited about computer programming. The thinking is that in a world of Apple iPads where there's an app for every occasion, people have become disconnected from the idea of getting their hands dirty and getting stuck into code. Raspberry Pi is designed to be a throwback to the 1980s PCs, the BBC Micros and Commodore 64s, that gave a generation of children their first taste of programming.

The idea is that these early machines made it simple to get started on programming. Turn one of these computers on and two minutes later you could have written your first program. That program might only have consisted of 10 Print "Hello", 20 Goto 10 but hey, it was a start. In contrast, computers today are geared around being simple to use and consequentially have OSes that hide away command-line interfaces, and shield the user from having to get to grips with anything as off-putting as actual computer code.

So what, keeping things simple is a good thing, right?
Not if you want to cultivate the next generation of computer scientists. The makers of the Raspberry Pi came up with the idea for the device after noticing a decline in the quality and number of students opting to study computer science at Cambridge University.

Raspberry Pi Foundation director Upton said he and his colleagues at Cambridge University had noticed that prospective comp-sci students had gone from arriving with a knowledge of several assembly languages to only having a working knowledge of HTML. He has said that trustees want to reignite students' passion for IT by making a machine that inspires children to tinker and hack into it, just like the PCs in the 80s.

Keeping the cost down was vital for the foundation. Upton said they wanted it to cost broadly the same as a high school textbook so kids can afford to get their own and start programming and hacking it at home.

So just how easy will it be to start programming the Raspberry Pi?
The device is designed to help users learn the Python and C programming languages, and will provide easy access to their programming environments, but will support a number of other languages such as Basic, Perl and KidsRuby, an easy-to-learn programming language aimed at children.

When can I get my hands on one?
The foundation estimates that the board will be available from November 2011. It plans to issue "significant" numbers by the end of the year and "substantial" numbers by the beginning of next year. At present, some 50 Alpha versions of Raspberry Pi have been made and are being tested by developers and the foundation staff.

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