The $5 Raspberry Pi Zero follows on from the wildly successful Raspberry Pi A, B and 2 computers, which cost $20 to $35.
But despite the staggeringly low price, it still has many of the same features, and runs about 40 percent faster than the Raspberry Pi 1.
At the heart of its 65 x 30 millimeter circuit board is a Broadcom BCM2835 application processor, the same as in the Raspberry Pi 1, with a 1GHz ARM11 core. The board holds 512MB of RAM, and the operating system is loaded from micro-SD card.
There's a mini-HDMI socket for 1080p video output, and micro-USB sockets for data and power.
The board is as expandable as its predecessors: Its 40-pin GPIO header has identical pinouts, although the pads on the circuit board are "unpopulated," meaning you'll have to solder on your own connector. The same goes for the composite video output: The connection is available, but if you need a socket, you must solder it yourself.
In comparison, the Raspberry Pi 2 Model B has additional memory, a quad-core processor, audio in/out, three additional USB ports, and direct connections for a camera and a display.