December 17, 2012, 3:43 PM — Todays smartphones are pretty good computers, but weve tried out three computational powerhouses that make the slimmest phone look like ENIAC. (The worlds first electronic computer, unveiled in 1946, weighed 27 tons and consumed 1800 square feet of floor space.) The Cotton Candy, the MK802 II, and the Raspberry Pi are amazingly tiny, incredibly inexpensive, and eminently customizable. They make terrific platforms for hobbyists fond of experimentation, and theyre ideal for students interested in learning how to program, but they can also serve as ordinary productivity machines.
These miniature marvels eschew the power-hungry x86 processors found in desktop and laptop PCs in favor of mobile CPUs and GPUs, but each relies on an external monitor or HDTVconnected via HDMIto display its user interface and other video output. In fact, the Cotton Candy and the MK802 II are the same shape and size as a USB memory stick, and plug directly into a TV. Thanks to that skimpy hardware, these computers can operate on just the trickle of energy provided by the display theyre connected to. Alternatively, you can plug in the same type of USB AC power adapter that modern smartphones and tablets use.
Much of the appeal of these pint-size PCs lies in their software versatility. Each device can boot from a MicroSD card containing an operating system disc image (typically some flavor of Android or a Linux distro tailored to its hardware set). If your tinkering utterly demolishes the stability of the OS, you can just overwrite the memory card with a new image and start over.
After comprehensive testing, I found that each of these micro PCs has its upside and downside, but all three devices shine in distinctly different scenarios.
What youll need to provide
Although each of these micro PCs is incredibly inexpensive, youll need to spend a little more cash on peripherals and accessories to render them completely functional. You'll absolutely need a USB mouse and keyboard, for instance, although you could borrow the input devices from another computer you already own. Raspberry Pi buyers will want to pick up an enclosure for protection (the device arrives as a populated circuit board sans case).
Depending on the port selection on your device, you might need to grab a USB hub to connect your peripherals. Be aware, however, that not every AC adapter will provide enough juice for the computer and a passive hub. (In my situation, the charger for my Kindle Fire did, but my smartphone charger did not.) You might also need to provide some of your own cables: The MK802 II and Cotton Candy come bundled with enough cables for the typical usage scenario, for instance, but nothing is included with the Raspberry Pi.