The Evolution of Single Board Computers

Single Board Computers (SBCs) have changed dramatically over the years. Initially the selection factor was based primarily on the CPU and its associated peripheral chips. Twenty years ago that meant Intel, Zilog, or Motorola were the silicon vendors for microprocessor systems. As the density, complexity and capability of the silicon improved, so did the choice and selection methodology for SBCs. Today software, board size, and time-to-market are the key decision factors in addition to just the power and speed of the CPU. Because of expansion options, there still remains a misunderstanding and perhaps mislabeling of an SBC. Historically, an SBC-based system has not necessarily been a single board. An SBC may have served as an initial building block, but expanding system options often dictated a mezzanine or backplane bus. Regardless of the form factor of an SBC, they all provide expansion options. Support for expansion is needed because of risk and uncertainty factors faced both by customers and vendors. Customers are driven by their sales and marketing departments from their customer inputs for more features, capabilities or options. Vendors want expansion options since they