The Raspberry Pi is a miniature marvel that shows just how small and cheap you can make a working computer. However, the device could benefit from having more memory at the risk of bumping the price up a bit.
Low cost, small size, built-in GPU supports 1080p video output
Restricted memory size, needs additional hardware and software to function
£21.60 + VAT and delivery
Processor: Broadcom BCM2835 SoC with 700MHz ARM1176JZF-S core
Display: Videocore 4 GPU supports resolutions up to 1920×1200
Storage: Slot for SD Card
I/O: 10/100 Ethernet, 2 x USB, HDMI, RCA phono, audio jack, GPIO header, microUSB power, DSI and CSI
Operating system: Images available to download from Raspberry Pi site
Dimensions: 85.6mm x 54mm
The Raspberry Pi is one of the most eagerly anticipated devices of the year, promising to deliver a low-cost platform for students to get to grips with programming. It has also sparked a huge amount of interest from tech enthusiasts.
Announced last year but with early production devices only starting to trickle out to buyers since April, the Raspberry Pi is a single-board computer based on an ARM processor and designed to boot from an SD Card flash storage device.
Buyers need to order a device from either RS Components or Farnell in the UK, but there is currently a long waiting list.
The model currently available is basically a developer tool intended to help build up an ecosystem of expertise around the Raspberry Pi ahead of the launch into the education market planned for later this year.
As such, the device is not for everyone; it is literally just a system board, delivered without a protective casing, power supply, or even any operating system included.
The buyer is expected to source all of the extra parts needed to turn it into a working computer, which means that it is not a particularly good choice for the average user.
That said, getting the Raspberry Pi working is hardly rocket science, and anyone who has ever rooted their smartphone or built their own PC from scratch will have little difficulty in building a functioning system.
At just £22, the Raspberry Pi is an easy purchase for anyone who just wants to play around with the device, although the extras needed to make it work can add up.
For example, we were unable to locate any display that could connect directly to the Raspberry Pi's HDMI output, so we had to fork out for an adapter that converts this to a DVI monitor input, which cost £21 from Maplin Electronics - pretty much the same as the Raspberry Pi itself.
To get started, users also need a flash SD Card at least 4GB in capacity; a mobile phone mains charger with a microUSB plug capable of providing at least 700mA of current; a USB keyboard and mouse; and a display with either an HDMI or composite video input.
Users also need a PC or other computer capable of writing the operating system image to the SD Card. Fortunately, we had access to a laptop with an SD Card slot, but many buyers may have to purchase another adapter for this purpose.
The Raspberry Pi is physically about the size of a credit card, and its functionality is largely provided through a Broadcom BCM2835 system-on-a-chip (SoC) which includes the 700MHz ARM processor, an integrated Videocore 4 GPU for graphics functions and 256MB of memory.
While this choice of processor makes for a compact design, it also limits the software that can be run on the Raspberry Pi, since there is no practical way to expand the memory beyond the built-in 256MB.
But the GPU is clearly quite capable, managing to drive a monitor at 1824x984 resolution in our tests, and is said to be capable of delivering full 1080p video.
Other hardware available on the Raspberry Pi includes an Ethernet chip providing 10/100Mbit/s network functionality, an SD Card socket, HDMI and phono video outputs, audio jack socket, two USB ports and a dual-in-line (DIL) header connector that exposes some general-purpose I/O connections from the processor.
The Raspberry Pi Foundation makes available three SD Card boot images that users can download to get up and running with their device. While the more tech-savvy users might want to try and compile their own Linux build for the Raspberry Pi's ARM chip and peripherals, a good start for most users is the recommended Debian build.