小眼睛的健康世界

To younger generations, today’s computing world began with the rise of the internet in the mid-’90s. In reality, home computing dates back to the late 1970s and early ‘80s. Built on the back of classic machines like the Commodore 64 and VIC-20, the Tandy TRS80 and the Sinclair ZX81, these small steps into the world of computing became surprisingly affordable. As newer, more sophisticated computers appeared on the market, older models were discounted, sowing in buyers the first seeds of doubts about ‘future proofing’. No- one really cared because these discounted models were cheap. Dirt cheap. I personally remember seeing Commodore Plus/4 and Texas Instruments TI99/4A computers being sold by electronics stores in Australia during that time for just $99. But it wasn’t long before the bean counters at Microsoft, IBM and Intel spoilt our fun, took the whole thing far too seriously and wanted to do serious work, of all the nerve! In a twinkling, hobby computers all but disappeared as ‘IBM-compatible’ became the buzzwords.

Over the last few years, there’s been a slow burn return to those frontier days. And it’s largely thanks to the internet and sites like Make, MakeUseOf and countless others. That slow build has turned into a stampede over the last six months, as low-cost ARM processors and Linux have grown into an irresistible combination. In fact, the next six months look set to be a full-on revolution.

Single-board computers

The return of low-cost computing scored its first goal in 2006 when the OLPC (One Laptop Per Child) project gained the support of the United Nations to build a low-cost laptop for kids in the developing world that could be built for under $100. Although it’s never quite hit that magic price point, further development of the ARM processor architecture and Linux has seen prices continue to fall.

Then word began to filter out late in 2011 that a UK group was about to stun the world with a tiny computer, featuring an HDMI output, USB and Linux. The price? An astonishing $38. A few people questioned whether a computer at that price could be of any use, but the developers needn’t have worried — since its release in March this year, worldwide demand for the Raspberry Pi has been so great that it’s almost permanently on back order. Today, they’re making 4,000 a day just to keep up.

The Raspberry Pi, available from www.element14.com for $38 plus shipping.

To be fair, the Raspberry Pi wasn’t the first single-board computer (SBC) on the market. Low-cost microcontrollers from Atmel and PIC have been around since the mid-1990s, but they’ve generally been single-task systems, used to create everything from car performance kits to stereo FM transmitters. The Pi was the first to show that ARM processors were now so cheap — yet powerful enough — to turn into low-cost full-function computers.

Since the release of the Pi, hardware developers have been launching themselves onto the bandwagon and there are now over 40 SBCs on the market. Most importantly, a dozen or so of them are crashing through the $100 barrier.

Under the bonnet

What makes these SBCs possible is the growing sophistication of ‘system on a chip’ (SoC) processors. These low-cost CPUs, based on the ever-popular ARM architecture, contain everything from memory controllers, USB ports and GPU all on the one piece of silicon. And they’re now becoming deliciously cheap. While popular chips from the likes of Nvidia, Samsung and Qualcomm drive almost every smartphone and tablet in existence, lesser-known, low-cost, high-performance parts are arriving from China.

Look at any budget tablet selling for under $150 on eBay at the moment and it’s almost guaranteed to be running an Allwinner A10 ARM chip. Rumours are this Chinese-developed CPU costs just $7 in quantity yet its single core clocks at up to 1.5GHz (much higher than the competition), features accelerated H.264 video and a 400MHz GPU for accelerated graphics. Throw in HDMI, Ethernet and USB, and you’ve got a powerhouse chip for the cost of a couple of coffees.

The Raspberry Pi itself features Broadcom’s 700MHz BCM2835 media applications processor. Not much is known about its price, but it’s rumoured to be costing the R-Pi Foundation around $11. For your money, the chip delivers full 1080p H.264 acceleration and HDMI output. It’s even designed to handle digital camera image sensors up to 20MP and a new 5MP camera module for the Pi has just been announced to sell for around $25.

SBCs like the Raspberry Pi are usually powered by USB, but require significantly more power if you start throwing in keyboards, mice and portable hard drives. Ideally, they need a 5V/2A power supply to keep them ticking over. You can pick these up from eBay for under $5 and most electronics retailers for under $20.

The block diagram of the Pi (below) shows just what the developers have managed to squeeze into this tiny system. The circuit board is multilayered like standard motherboards and in the case of the Pi, also comes with what’s called a General Purpose Input/Output (GPIO) bus to allow you to interact with the outside world, such as turning lights on and off, operating solenoids and other external electronics.

Block diagram of the Raspberry Pi circuit board.

 

What’s available?

As we said, the Raspberry Pi is really just the battering ram for this ultra-cheap computing juggernaut. We managed to pick up three, including the Raspberry Pi, for this feature, but there’s a flood of other models either just about to hit the market or in various stages of design.

The most notable models are the Rikomagic MK802, a tiny Allwinner A10-powered computer little larger than a USB flash drive selling for around $75 on eBay; and the VIA APC.

 

However, the real action is in what are called Android TV boxes. They masquerade as digital media players and there are plenty of them selling online for under US$100, yet they have everything needed to turn them into low-cost computers. In fact, there’s a growing community dedicated to hacking Allwinner A10-based TV boxes and running custom-built Linux distros on them. And don’t kid yourself that they can’t do it either — with up to 1.5GHz clock speed, the Allwinner A10 is gaining a reputation as a surprise packet that outclasses the Raspberry Pi.

The model we saw as we went to press was the new TV Cloud Stick, which offers a 1GHz Telechips TCC8925 ARMv7 processor, Android 4.0 operating system, HDMI output and twin USB ports, all in a USB stick format for just $60 on eBay.

What’s coming?

No doubt some will dismiss SBCs as just toys, but we’re getting way past that level. Korean makerHardKernel sells the ODROID-X, an open-source Android development platform, for US$129. For that price, you get a Raspberry Pi-like SBC with — wait for it — a 1.4GHz quad-core Samsung Exynos 4412 ARM processor, six USB 2.0 ports, microHDMI output and Android 4.0.4 operating system. Plug in a keyboard, mouse and HDMI monitor, load up the operating system via SD card and you’re away. You can even install Google Play or Ubuntu 12.04 Linux. It might be a bit over the $100 mark, but the level of hardware here is just extraordinary — you’re talking about the very same CPU that’s inside Samsung’s Galaxy S III smartphone. We’re definitely a long way from Commodore 64 performance here.

During the writing of this feature, we found new SBCs being launched almost weekly, so while tablets and smartphones are changing the face of consumer computing, the same components are now becoming available for hobbyists in working SBCs at much cheaper prices. Below are some of the sub-$100 SBCs available.

Serious performance

Don’t think the big end of town hasn’t noticed. SoCs are the new kid on the block in corporate servers, yet they’re gaining fans, based on their ability to deliver considerably more performance than traditional server solutions per unit of electrical power. Calxeda has developed ARM server solutions around its EnergyCore ARM SoC that are now sold by HP. Dell is using Marvell’s Armada XP 78460 SoC inside its new Copper ARM microservers and to show off how power-miserly SoCs can be, Red Hat recently demoed an ARM-based server powered by a bicycle.

single board computer The future

However, it’s the hobbyist computer reborn out of ARM processors and Linux/Android operating systems that are clearly far more fun. The team behind the Raspberry Pi had the goal to make a low-cost computer that kids could afford, have fun with and learn how to program. In reality, they’ve spawned a new industry. Sure, the Pi and others like it aren’t going to replace your PC any time soon (although the ODROID-X is getting damn close), but you can be certain they’ll only improve over time as dual and quad-core ARM chips drop down in price. Right now, the Raspberry Pi can browse the web, handle Word documents and Excel spreadsheets, and play 1080p H.264 video.

Personally, I’m just waiting for someone to build a Raspberry Pi inside a full-sized keyboard. Now that really would take us back to the Commodore 64…