"Some of these products also provide CompactFlash or PCMCIA
slots, which facilitate both memory and peripheral interface
expansion. Many now include support for operation from batteries,
making them ideal platforms for specialized handheld and portable
equipment.
"One noteworthy concern relative to this class of products, with
the exception of PC/104 form-factor SBCs (which are too numerous to
include here), is the utter lack of plug-and-play interoperability
among these tiny modular systems. Although there is the hint of a
trend toward matching the size and connector styles of DIMM or SIMM
memory modules, there is no consistency whatsoever in how their
signals are assigned to the module connectors. Also, with many of
these products taking advantage of the latest high-integration
system-on-chip processors (StrongARM, Elan, Etrax, etc.), which are
not typically x86 compatible, PC compatibility has become the
exception rather than the rule.
"However, despite their lack of plug-and-play interoperability,
the availability of embedded Linux ports for these tiny SBCs,
combined with their excellent integration/size ratios, make these
products highly appealing for applications that can't tolerate the
size of standards-compliant SBCs. The hope, of course, is that
using one of these tiny single-module-systems will eliminate the
costly, risky, and time-consuming process of developing a custom
embedded computer."