Raspberry Pi Model B

Overview of the Raspberry Pi Model B

An entire computer printed on a single circuit board; the Raspberry Pi Model B is no bigger than a credit card, even though it possesses all the components needed for running an operating system, including Windows, Mac and Linux. The operating system of choice must first be installed by the user onto the Raspberry Pi circuit board.

The principal aim of the Raspberry Pi, as developed by the UK charity The Raspberry Pi Foundation, was to function as an educational tool to promote interest in basic computer science amongst school pupils. A growing army of hobbyists has also taken it up, since its official launch in 2012.

The device includes a “system-on-chip” or SoC: a BCM2835 processor manufactured by Broadcom which possesses all computer components in a single integrated circuit. Also on its Printed Circuit Board (PCB) are two connectors, one for input and the other for output.

The Raspberry Pi Model B is actually the higher-priced of the two models devised by the Foundation and is currently priced at £26.00 (the Foundation began taking orders for the lower cost Model A on 4th February 2013 while Model B was launched earlier, on 29th February 2012).


History of the Raspberry Pi Model B

The idea behind the Raspberry Pi was hatched in the mind of computer expert Eben Upton as he was completing his PhD in computer science at Cambridge University in 2006. As a child, he had been an enthusiast of the BBC Micro computer built by Acorn and installed in most UK schools during the 1980s. He especially liked the fact that the computer was robust and inexpensive, and could be expanded – characteristics that went into the making of his Raspberry Pi concept.

In 2006, as a trustee and founder of the Raspberry Pi Foundation, he brought together a group of computer aficionados, teachers and academics to bring the Raspberry Pi concept to life – a computer to excite the interests of a new generation of children in software programming and hardware engineering.

The first prototype device the group developed consisted of a 32-bit Reduced Instruction Set Computer (RISC) from the technology company ARM (Advanced RISC Manufacturers). The whole package was roughly equivalent in size to a USB memory stick and included, at either end, one HMDI port and one USB port.

By 2011, the device had evolved to resemble a slightly larger version of the proposed Model B (the size was necessary to house debug headers). It was capable of running the open-source LXDE desktop environment on Debian, the video game Quake 3 at 1080p and, with its HDMI capability, full high-definition MPEG-4 videos. In October, the RISC component was updated to OS5 and, after twelve months of development, the port was released for public consumption the following month.

The finished Model B product was launched on 29th February 2012 and sales were phenomenal. Within the UK, the two manufacturers licensed to sell the Raspberry Pi – Premier Farnell and RS Components – both found their online store websites paralysed by heavy traffic directly after the launch. By September 2012, sales of the boards tipped the 500,000 mark. Model B was revised in September 2012 and the Foundation announced that, henceforth, manufacture of the device would move from China and Taiwan to the UK, at Sony’s plant in Pencoed, Wales.

By the close of October 2013, 2 million Raspberry Pi’s had been shipped.


Technical aspects of the Raspberry B Model B

Raspberry Pi Model B features a 10/100 Ethernet controller and two USB ports. Debian and Arch Linux ARM distributions can be downloaded from the Foundation’s online one-stop shop, the “Pi Store.” The device’s main programming language is Python and novices to computer language can find tools to help them use it from the Pi Store.

The device also includes a General Prose I/O (GPIO) expansion board connector, a slot for the SD card, an a 3.5mm headphone jack for analogue audio output.

The SoC includes a 32-bit ARM1176JZFS CPU designed to run at a clock speed of 700MHz, although the firmware features several “Turbo” options allowing users to try speeding up (overclocking) the CPU without invalidating the warranty. Also on the SoC is a Videocore IV graphics processing unit (GPU). The device is powered by either 4 AA batteries or via a 5V micro USB AC charger.

The original RAM was 256 MB, but this was expanded to 512 MB in October 2012, and booting and long-term storage is via an SD card rather than an integral solid-state drive or hard disk.


Things you do with the Raspberry Pi Model B – any famous instances?

Because the Raspberry Pi Model B with its two USM ports is compatible with generic USB keyboards and mice, it can be used as small, low power desktop computer. The device’s ARM CPU delivers a performance equivalent to a 300MHz Pentium 2 processor, and its Broadcom GPU is an exceptionally capable graphics component able to decode a range of HD video formats, which enables it to be used as an inexpensive home theatre personal computer (HTPC).

The chief appeal is to schools, largely because even when purchased in bulk, the Raspberry Pi Model B is a fraction of the cost of a fleet of desktop PCs and will introduce children to computer programming in a highly practical and engaging way.


How the Raspberry Pi Model B differs from the Raspberry Pi Model A

Unlike Model B, the Raspberry Pi Model A has only one (instead of two) USB ports and no Ethernet controller.