ARM and the long tail of Acorns RISC computers

Posted on January 9, 2011


Right now, ARM is maybe one of the best, most silent and most successful challengers of Intel’s x86 dominance.

If you would ask me: “who the fuck is ARM?” I would not blame you. As they have been a very modest builder of dominance in the mobile world and do not advertise: “ARM Inside” on any device that contains one.

According to this CNET article from 2006: ARM has created the chip design that is at the center of virtually every mobile phone on the planet. About 98 percent of all mobile phones use at least one ARM-designed core on their motherboards.

Bottom line: ARM rules almost everything that is running an OS and currently is not a PC, laptop, Netbook or (web) server.

In 2011 even this will change. ARM and their partners are – (see this video from Charbax at ARMdevices regarding the new Qualcomm ARM processor series for one example) – working hard to move to the desktop as well.

Thus re-entering the market where the ARM RISC processor (as the heart of the now dead Acorn RISC Desktop Computers) started about 20 years ago.

Android, or: How ARM got on my radar again

Until I bought my first Archos tablet running Android and started reading into ways of hacking that hardware platform I thought ARM had moved slowly into obscurity. RISC had its time in 1990 and failed to break through as an alternative to CISC processors like the x86. IBM, Apple and Moterola had produced the PowerPC but the brand, Apple, that had made a bold move against Intel, finally seemed to budge and moved to Intel x86 in 2005.

Mobile phones did run some kind of processor, but I categorized them under “Whatever”, “HTC” and “Nokia”.

Intel had won the race for PC dominance and that was it.

As my interest in hardware had reduced to almost zero, I had been clueless about what was going on with ARM in the world around me.

Overview, some backgrounds and new developments

ARM is not just telephony and devices anymore. It is not just low-power, 600 MHz single core processors. Only a few days before this article was written, Microsoft announced and demoed Windows 8 on the ARM Cortex-A9 processor. Qualcomm, TI and Nvidea are developing ARM powered desktop systems. RISC seems to be coming back into view again.

In this article you will find a simplified time line and some backgrounds and new developments.

Acorn: The unknown third

At the end of the 1980’s the choice of computers in my peer group was either an Amiga or an Atari. If you had a PC you were either a geek or an idiot who had missed out on where the cool was, as they were retarded (non visual DOS and 16 colors maximum) in comparison to the sheer (gaming) power and style of both. Apple was overpriced and – like the PC – below our standards of those days.

I had an Amiga 500.

Then there was Acorn computers with their Acorn Archimedes. A very obscure brand which dominated the UK but was completely unknown in the Netherlands – unless you were a total computer geek and did not mind the lack of peers. At that point in time corn was only sold at two locations in the Netherlands. Only one guy in our class had one: Ronald. What he boasted was that it kicked ass of both the Amiga and the Atari (who kicked who’s ass in that camp was up to which machine you owned). And he was right when it came to raw processing power.

What Acorn had done was – instead of jumping on the Motorola 68000 bandwagon – which had a 32 Bit architecture instead of the 16 Bit x86 – Acorn created their own processor, based on Reduced Instruction Set Computing or RISC.


Where the 68000 and the x86 had a (very) rich Machine Language instruction set, the Acorn RISC processor reduced the instruction set to the bare minimum, which led to the following benefits:

  1. Simplification of the CPU design – as each instruction is reflected in electronic circuits, reflected in the micro-chip design, the chip itself becomes simples
  2. Reduction of the required amount of transistors – Less instructions = less transistors
  3. Reduction of power consumption – Less transistors = less power consumption
  4. Almost double the processing speed for the same price – Where the 68000 machine-code instructions could take up to 32 bits, one Word or 4 Bytes, the variables would automatically be in the next Word or the next slot of 4 Bytes. It would then take two clock-cycles to process the instruction and the variable. With a reduced instruction set below 256 op-codes you could fit the instruction of 8 bits / one Byte WITH the variable you wanted to use in the other 3 Bytes, leading to the need of only one clock-cycle for many of the instructions you wanted to perform.

Acording to this paragraph in the Wikipedia article on RISC, RISC no longer indicates “less instructions than CISC”. Other factors that made RISC stand out in the early years where either reduced due to (see info here) Intel’s almost limitless resources, faster development cycles and – according to DEC – stolen information from the architecture of the DEC Alpha CPUs which Intel produced along their own line of processors. But that is a different story.

Time line

You can find the basis of this time line in this Acorn Wikipedia Article and this milestones list from ARMs website. Also find a brief history writup by Charbax here and from the National Inquiry here.

  • 1987: Acorn Archimedes – the first ARM / RISC based computer for the consumer market.
  • 1990: ARM is created as a spin-off company – from Acorn, focusing on the ARM microprocessor core
  • 1993: Apple launches the Messagepad – with the ARM 610 RISC processor
  • 1994: Acorn Risc PC – a more PC-like system running the Windows like RISC OS, moderately successful, but could not compete against the raw market power of the Intel PC.
  • 1994: Acorn Set top boxes / Video on demand – Attempt to create a system for video on demand. Did not break through
  • 1996: Acorn starts joint venture with Apple UK, Xemplar – Attempt to get into the educational market again. Did not succeed
  • 1996: The Acorn Network Computer – A joint venture with Oracle which commercially did not work out due to – regardless the hype created in that period – lack of interest in such devices.
  • 1998: The break up of Acorn -Olivetti, as one of the major financial backers, withdraws. Acorn is broken up in parts and the desktop-devision is closed.
  • 1998: ARM goes IPO – And continues their own line of successes.

With a – from a consumer market point of view – unlucky chain of choices, including producing set-top boxes and network computers by Acorn, ARM could have gone under with the company. They did the opposite.

2011, the year of ARM

I think we can call 2011 the year of ARM. After flying for almost 15 years under my radar they emerge almost victorious with a strategy that I understand to be as follows:

  1. Work together – Instead of trying to be the one company building that one computer (the Acorn RICS line) they worked together with- and licensed their technology to- several different vendors and producers.
  2. Licence your technology – Instead of building the chips themselves ARM lincenses their technology to other Chip Manufacturers, including Nintendo, Qualcomm, Samsung, Sharp, STMicroelectronics, Texas Instruments, VIA and VLSI

This is where we are now:

  1. Leading provider of low-power-consumption CPUs – Almost – if not all – mobiles and tablet computers you know – including the iPad – runs on the licensed technology of ARM
  2. Leading provider (via license takers) of non-Intel CPU – If it is not Intel (or an Intel “clone” like AMD), it is an ARM processor.
  3. More and more ARM-powerd hardware – Whether it is eBook readers, mobile phones, tablet computers, Netbooks or the Apple A4 inside the iPad.
  4. Many tastes of operating systems: Including iOS, Debian, Fedora, OpenBSD, Windows Mobile and Android
  5. Multi core, higher clock speed and support for larger RAM – Introducing a multi-core processor and support for larger memories means the ARM processors are scaling up to Intel Regions.
  6. Games and 3D support – Archos already offered this on their Gen9 tablets and chip-manufacturers are focusing on it for the next wave. There is an Unreal engine for the ARM chipset and you can already download 3D games for the iPhone and Android (Archos).

This is what we can expect:

  1. Faster tablet computers, more choice and better user experiences – overcoming the performance issues we have seen the past years with machines running on 600 MHz and less, and with iOS and Android battling for the next waves of consumers in the years to come.
  2. Tough competition for hand held game devices – as the market will blend and phones and tablet computers will offer similar experiences as the DS and Playstation portable.
  3. Servers and Desktop Computers powered by ARM – With the built-up traction ARM has, the marketing-support from Google with ChromeOS and Android and most Linux and BSD bases operating systems able to run on ARM processors, using ARM processors for desktop-machines and servers might prove to be more successful than in 1995.
  4. Windows 8 to run on ARM – According to this release – and in this video I already linked to, with Steve Ballmer Microsoft demoed  the next version of Windows, Windows 8: “System On a Chip” on an ARM processor in systems by Texas Instruments, Qualcomm and Nvidia at CES 2011.