40 years of Arm celebrated in Cambridge
In April 1985, a nimble team at Acorn Computers in Cambridge – the company which had successfully developed and marketed the BBC Micro – set out to rethink what a processor could do.
Two highly ambitious Arm engineers – Sophie Wilson and Steve Furber – were tasked with designing a 32-bit processor.
Why? It started in 1978, when Chris Curry and Hermann Hauser co-founded Acorn , a startup with roots in Cambridge and a knack for spotting opportunity. In 1981 the company was awarded the contract to build the BBC Micro as part of a UK government initiative to place a computer in every classroom. This was a pivotal moment – not just for Acorn, but for the future of computing.
To power the BBC Micro, Acorn initially relied on the 6502 microprocessor. But as Acorn began dreaming of more powerful machines, the company decided to build its own processor – an outrageous move for a small firm at the time.
The result? The ARM1, where ‘ARM’ stood for ‘Acorn RISC Machine’, with RISC being a ‘reduced instruction set computer’. This was initially an unassuming chip with just 25,000 transistors, defined by simplicity, speed, and extreme efficiency. For comparison, Arm’s chip for Apple’s M3 Ultra SoC – currently on sale – is home to a record 184 billion transistors.
But Sophie (born Roger) and Steve were nothing if not ingenious. Single-cycle execution – where instructions are carried out within one clock cycle – resulted in faster processing. RISC processing had simpler instructions, but could process many more of them, which speeded up operations. RISC architectures also introduced pipelining, which breaks down instructions into smaller steps that can be processed concurrently, further enhancing performance.
For sure, some of these innovations emerged from necessity – the need to short-cut processing time, reduce memory use, to do more with less. It was the same sort of necessity born of ingenuity that allowed the Apollo Guidance Computer on Apollo 11 – with 32kb of RAM and 72kb of ROM – to land on the Moon.
The outcome of the Swaffham Bulbeck team’s nous laid the foundation for what modern computing would become. And, under inaugural CEO Sir Robin Saxby’s leadership, it also laid the foundation of a company that now turns over more than $3.3bn a year and employs 7,000 people, four-fifths of whom are engineers.
Today, as the original Arm architecture turns 40, that same DNA lives in over 250 billion chips, powering billions of devices from sensors to datacentres and beyond – a testament to the scalability and versatility of Arm’s architecture.
This historic milestone was celebrated with a visit to Arm’s Swaffham Bulbeck HQ at the time, with all its reminders of past times revisited by those who worked there in the early years.
The birth pangs of the digital era took place in the huge barn.
After Arm was officially founded as a company in 1990, the ARM architecture continued to evolve with the introduction of ARM6 in 1991. The ARM6 architecture – which fully supported 32-bit processing and included features like a memory management unit (MMU) – was the computing foundation for the ARM7 processor which then became the flagship design for GSM mobile phones in the mid to late 1990s – this started with the Nokia 6110 which was a huge commercial success.
If you want to find out more you can visit the Centre for Computing History, which is hosting an anniversary exhibition until the end of May. The celebrations began at 3pm on Saturday (26 April), the moment the chip that led to the world’s first commercial RISC processor powered up 40 years ago – and changed the world.
Sophie Wilson, Steve Furber and others were there to talk about that iconic moment, and visitors will be able to try out some coding and explore the new exhibition which celebrates the origins of Arm Holdings.
But if you can’t make it don’t worry, you’re still part of the Arm success story every day of your life: every time you pull your smartphone out of your pocket, you’re paying tribute to some of the greatest heroes in the history of humanity’s technological success story on this planet.
So now you know!
