Archimedes principle
The ARM DS was followed, in 1987, by the first complete ARM-based computer, the Acorn Archimedes, costing a hair under £900. The various Archimedes machines that followed were among the most powerful home computers available, and by the time the last one arrived, in 1992, the processor had evolved to include a crucially important new feature. It was this that would prepare the chip for its triumphant role as the dominant mobile powerhouse.
The ARM had become a system-on-a-chip (SoC).
The key was the relatively small real estate on the die required by the processor proper, leaving plenty of room on the surrounding silicon for whatever else might take the designer’s fancy.
Says Furber: “You could just think about the four chips you needed to build the Archimedes system, and putting them onto one chip.”
A large, ailing computer company across the Atlantic had seen the potential for this early on in the game. In 1986, Apple began using ARM processors for backroom prototypes of what was to become the first ever tablet computer, the Newton. Five years later, Apple ploughed a reported $1.5m into the newly-founded ARM company, taking a 43 per cent share of the joint ownership along with Acorn and the processor fabricator VLSI.
The Newton, launched in 1993, was a flop. But by the turn of the millennium, Steve Jobs was back in the saddle and Apple’s investment in ARM went on to pay huge dividends as the Cupertino company branched out into portable devices like the iPod, the iPhone and the iPad.
Acorn Computers, meanwhile, had unravelled. An escape vessel from the wreck was a company focusing on Digital Signal Processor (DSP) design called Element 14. Sophie Wilson was a key crew member, and when Element 14 was bought by Broadcom in 2000, Wilson went with it, to become, as she is today, chief architect of Broadcom’s DSL business.
ARM-powered but not Apple's saviour: the MessagePad 100
Source: Wikimedia
Herman Hauser was once asked why a great British success story like Acorn finally failed. He queried the last word: “There are over 100 companies in the Cambridge area that can trace their beginnings back to Acorn, and have been founded by Acorn alumni. ARM has now sold over ten billion processors, ten times more than Intel.”
Since 2008 when Hauser made that statement, ARM-based processors not only monopolise our smartphones, but also appear in 90 per cent of our hard drives, 80 per cent of our digital cameras, and have also found their way into printers and digital TVs. They are currently selling at a rate of over five billion per year. ®
ARM creators Sophie Wilson and Steve Furber
COMMENTS
Superb
Almost brought a tear to my eye. A beautiful article about a beautiful piece of technology. My jaw dropped when I read the ARM worked without applying Vcc :)
IBM ROMP vs. ARM
The IBM ROMP chip (aka the 801) was never intended to be a general purpose RISC processor. It was intended to power an office automation product (think of a hardware word-processor like WANG used to sell).
As a result, although it could function as a General Purpose CPU, it was not really that suited for it. It was never a success because at the time, IBM could not see justification for entering the pre-Open Systems UNIX world. RT 6150 and the 6151 were intended as niche systems mainly for education, although they did surface as channel attached display front ends for CADAM and CATIA run on mainframes (and could actually run at least CATIA themselves). This changed completely with the RIOS RISC System/6000 architecture, where IBM was determined to have a creditable product, and invested heavily.
In comparison, the ARM was designed from the ground up as a general purpose CPU. Roger Wilson (as he was then) greatly admired the simplicity and orthogonality of the 6502 instruction set (it is rather elegant IMHO), and designed the instruction set for the ARM in a similar manner. Because the instruction set was orthogonal (like the 6502, the PDP11, and the NS320XX family), it makes the instruction decoding almost trivial. It also made modelling the ARM on an econet of BBC micro's (in BBC Basic, no less) much easier, which allowed them to debug the instruction set before committing anything to silicon.
They had to make some concessions on what they wanted. There was no multiply-add instruction, which appeared to be a hot item in RISC design at the time, and to keep it simple and within the transistor budget, all they could do was a shift-add, (the barrel shifter), which although useful, was a barrier to ultimate performance, but great for multi-byte graphics operations.
It was also simple enough so that they could design the interface and the support chips (MEMC, VIDC and IOC) themselves, achieving early machines with low chip counts.
This is all from memory of articles in Acorn User, PC World, Byte and other publications. Feel free to correct me if my recollections are wrong.
Fantastic article
This is why I come to the Reg, so much nicer to read a well informed structured article as opposed to the usual "my dads bigger than your dad" fanboy rantings on other sites
A*
Brilliant!
I would just like to congratulate the author of this article. Beautifully written. A real credit to yourself, and The Register, sir. Thank you very much.
It struck me that Hauser, despite not being the technical guy, is as bright as they come. He clearly recognised the talent he had with Wilson and Furber.
I completely riviting read. Actually, the story of Acorn & ARM would make a very good book. Ditto Inmos IMHO.
Have a good day all.
Re: Great article
I agree, it wasn't Acorn and the ARM which failed.
But there is something about the British industrial and financial environment which seems to let the winnings from these works of genius drift away out of reach.
Its not just globalisation, and some factory that is so expensive to build that there can only be one on the entire planet. And we can't expect to spot the right investment choice every time. But what is it about this country which turns a successful entrepreneur into somebody fronting a TV show that tests how people can run a market stall in Essex?
