Happy birthday, ARM1. It is 35 years since Britain's Acorn RISC Machine chip sipped power for the first time

Somewhere in your phone, something is blowing out candles on a cake

45 Reg comments Got Tips?

Video Did the reminder on your smartphone go off over the weekend? It's been 35 years since the first Arm processor was powered up.

"At 1pm on April 26th 1985," recalled Prof Steve Furber, "the first ARM microprocessors arrived back from the manufacturer – VTI [VLSI Technology, Inc]. They were put straight into the development system which was fired up with a tweak or two and, at 3 pm, the screen displayed: 'Hello World, I am ARM'."

Furber and fellow engineer Sophie Wilson had enjoyed considerable success back in the 1980s at Acorn Computers – Britain's answer to Apple – thanks to the BBC Micro, based on the ageing MOS 6502 processor. Famously, the duo had managed to put together a prototype microcomputer in a week or so to satisfy the BBC, leading to the launch of the eponymous Acorn-built home computer in 1981.

By 1983, recognising that the 6502 was coming to the end of the road, the Acorn RISC Machine project was kicked off. Wilson had created a simulation of the 32-bit microprocessor's instruction set in 808 lines of BBC BASIC while Furber focused on the hardware architecture, which featured a three-stage pipeline and barrel shifter. They assembled a small team, and turned to chip fabricator VLSI to churn out the first samples of the silicon. The first chips worked as expected, 35 years ago.

Acorn co-founder Hermann Hauser recalled: "While IBM spent months simulating their instruction sets on large mainframes, Sophie did it all in her brain."

Incidentally, the first ARM1 chips required so little power, when the first one from the factory was plugged into the development system to test it, the microprocessor immediately sprung to life by drawing current from the IO interface – before its own power supply could be properly connected.

The early chips, which executed roughly three to eight million instructions per second, outperformed Intel's 80286 while sipping less current. Performance would continue to be improved over subsequent years, though the chip was not enough to save the fortunes of Acorn, which had been snapped up by Olivetti as the first Arm silicon arrived.

The first-generation Arm chip found use as a co-processor for the BBC Micro and a follow-up, the ARM2, and subsequent iterations, found their way into Acorn's Archimedes, and later the RiscPC, lines of computers.

Famously, despite the lack of wild commercial success enjoyed by Acorn's personal computers, Apple began sniffing around the technology as something that could be used to power its Newton computing platform. The result was the spinning off of the bits of Acorn's Research and Development team responsible for the RISC microprocessor into a new company, Advanced RISC Machines, in November 1990. Wilson stayed on to consult (and would later turn up in an architectural role at Broadcom in Cambridge.)

You can watch a fascinating video of Arm's pitch to Apple engineers in 1992 here, courtesy of The Centre for Computing History:

Youtube Video

The Newton, which eventually used the ARM610 and shipped in 1993, was infamously not Apple's most successful product, and the PDA was axed in 1998.

However, the experience taught Arm a person cannot live on Apples alone (at least, not then), and under then CEO Robin Saxby, the design house pursued its unusual (for the time) IP business model with gusto. That model served the company well and Arm's CPU and GPU blueprints have been licensed to many semiconductor companies in return for an upfront fee and per-chip royalties thereafter.

For example, even as the Newton fiasco was sputtering to a halt, Arm's designs were creeping into other devices, most notably everyone's favourite Snake game console: 1998's Nokia 6110, which was the first GSM phone powered by Arm's technology.

Arm went public on April 17, 1998, at a share price of 575p. The dotcom boom inflated things briefly before Arm (and much of the tech industry) returned to Earth. However, Arm's march to dominance was well underway thanks to its licensing model that permitted its tech to be integrated into more and more system-on-chips.

The addition of the Cortex line of processors saw Arm's designs dominate the portable device arena by the time Japan's SoftBank acquired the company in 2016. SoftBank went on to sell off part of Arm to a China-led investment group in 2018.

The low-powered chip designs have also found their way into more traditional laptops and computers, as well as servers. After his stint at Acorn, Furber went on become a professor at the University of Manchester in England, and most recently used hundreds of thousands of ARM9 CPU cores in 19-inch server racks to build a computer to mimic the workings of the human brain.

Arm, now with offices all over the world, has seen off much of its competition over the years – particularly its arch-nemesis MIPS – and licensed its technology, from CPUs to GPUs and accelerators, to a broad spectrum of manufacturers. It now has to fend off the fledgling upstart open-source RISC-V architecture, which poses a threat to its business model.

For this hack, however, the "A" in arm will forever be "Acorn". Thirty-five years on, please join us in raising a glass to the boffins behind that first bit of silicon. ®

SUBSCRIBE TO OUR WEEKLY TECH NEWSLETTER


Biting the hand that feeds IT © 1998–2020