Measuring a mere 20 by 80 by 8 mm, the gumstix 400x single-board computer is powered by a 400-MHz PXA255 XScale processor. It comes complete with 64 Mbytes of SDRAM and 4 Mbytes of flash memory. The 400x consumes less than 250 mA, suiting it for battery operation. In sleep mode, it uses under 50 mA. The 4 Mbytes of flash are programmed with the u-boot-1.0.0 loader, the 2.6.4 Linux kernel, and a root file system.
The boards contain two serial ports, a USB client, and support for an MMC/SD flash memory card. The gumstix incorporates a JTAG interface and works with the usual open-source Linux tool chain.
The gumstix 400x costs $139. A 200-MHz version runs $109, and the tiny 200x kits start at $139.