RISC chips have fewer transistors and simpler architectures, but they can be programmed to perform very efficiently. They also use a lot less power than more conventional processors, which makes them ideal for use in systems that either have limited power and should not overheat, like mobile phones. This explains why ARM chips are now found in phones and mobile devices from Nokia, Samsung, Sony Ericsson and of course Apple. Although ARM started within Acorn, it didn’t stay therer. In November 1990 Acorn created a joint venture with Apple and chip manufacturer VLSI, and Advanced RISC Machines Ltd was created to develop the ARM architecture, and since then it has grown into the most succcesful British company to have emerged from Silicon Fen, with offices around the world and chips in billions of devices. Part of the secret of ARM’s success is that it doesn’t actually make many processors itself. Instead it licenses its designs to other companies who then incorporate an ‘ARM core’ in their own more complex processors, which they then manufacture themselves.
Their designs now fall into three groups, or profiles. Application, for general processing, real-time, and microcontroller, for the embedded systems found in many machines. Anyone who wants to play with an ARM processor can get their hands on one very easily from mbed, an ARM research project that supplies an ARM Cortex microcontroller on a 40 PIN board with a USB interface and a variety of web-based support tools that let you write and compile programmes in C and C++ Like the open source Arduino platform, it is designed to encourage exploration, learning and prototyping, with a large and growing web-based user community who share ideas and code. And next week the mbed engineers are celebrating ARM’s twentieth anniversary in an appropriately geeky way by running a robot racing competition using an mbed-controlled robot that can be driven using an Android tablet (see http://mbed.org/cookbook/mbed-Robot-Racing for details). In the 1990’s most of us assumed that Acorn’s main impact would prove to be the generation of people who sat down in front of the startup screen of a BBC Micro and grappled with a command line to type in their own BASIC programs, but twnty years later it’s the billions of ARM processor cores in smartphones and handheld computers around the world that are shaping our world.
ARM has become into one of the most important companies propelling us into the age of electronics, and has shown remarkable skill in navigating in the new environment it has helped to create. I can’t wait to see what they will have done by their fortieth anniversary. Bill’s Links The LaserWriter http://www.mac512.com/macwebpages/lw.htm
About ARM http://en.wikipedia.org/wiki/ARM_Holdings
The ARM architecture: http://en.wikipedia.org/wiki/ARM_architecture
mbed Blog and robot racing: http://mbed.org/blog/
Why understanding computers matters: http://www.bbc.co.uk/news/technology-10999734