Introduction to Single Board Computer (SBC)

Definition of Single Board Computer

What is single board computer? It can be abbreviated as SBC, and it is a complete computer built on a single circuit board with a microprocessor, memory, input/output (I/O), and other features required by a functional computer.

Single board computers are often manufactured as demonstration or development systems, used in educational systems, or as embedded computer controllers. Many types of home computers or portable computers integrate all their functions onto a single printed circuit board.

Unlike desktop personal computers, single board computers usually do not depend on expansion slots for peripheral functions or expansion. Single board computers have been built using a variety of microprocessors. Simple designs (like those built by computer enthusiasts) usually adopt static RAM and low-cost 8-bit or 16-bit processors. Other types, such as blade servers, will only perform operations similar to server computers in a more compact format.

A computer-on-module belongs to a type of single board computer that can be inserted into a carrier board, backplane, or baseboard for system expansion.

History of Single Board Computer

The first true single board computer was called “dyna-micro”. It was based on Intel C8080A, and also used Intel’s first EPROM C1702A. The dyna-micro was renamed as “MMD-1” (Mini-Micro Designer 1) by E&L Instruments of Derby, Connecticut in 1976, and was used as an example microcomputer in the very popular 8080 “BugBook” series of the time.

SBC also played an important role in the early history of home computers, such as in the Acorn Electron and the BBC Micro. Other typical early single board computers (such as KIM-1) usually did not have an enclosure and must be added by the owner.

As the PC market became more and more common, fewer and fewer SBCs were being used in computers. The main components were assembled on the motherboard, while the peripheral components (such as serial ports, disk drive controllers, and graphics processors) were located on the daughterboard.

Advanced chipsets have recently provided most of the I/O features as embedded components, which enables motherboard manufacturers to provide motherboards with I/O traditionally provided by the daughterboard.

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Today, most PC motherboards provide onboard support for disk drives, including IDE and SATA with RAID, graphics, Ethernet, and traditional I/O, such as serial and parallel ports, USB, and keyboard/mouse support.

Applications of Single Board Computer

By increasing the density of integrated circuits, single board computers became possible. The single board configuration reduces the overall cost of the system by reducing the number of circuit boards required and eliminating connector and bus driver circuits.

By putting all the functions on one board, a smaller overall system can be obtained. Connectors are a common source of reliability problems, so the single-board system eliminates these problems. Single board computers are now usually defined in two different architectures: no slots and slot support.

The embedded SBC is a unit that provides all necessary I/O without providing a plug-in card. Applications are usually gaming (slot machines, video poker), kiosks, and machine control automation.

The embedded SBC is much smaller than the ATX type motherboard in the PC and provides an I/O combination more suitable for industrial applications, such as onboard digital and analog I/O, onboard bootable flash memory (eliminating the need for a disk drive), no video, etc.

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Single board computers are most commonly used in industrial applications, in a rack-mounted format for process control or embedded in other equipment to provide control and interfacing. They are used in deep-sea exploration on the ALICE deep sea probes and in outer space, on the Ariane and Pegasus rockets and Space Shuttle.

Due to the high degree of integration, reducing the number of components and connectors, SBC is often smaller, lighter, more energy-efficient, and more reliable than similar multi-board computers.

Compared with SBC, the main advantage of ATX motherboards is cost. Millions of motherboards are produced for the consumer and office markets, enabling huge economies of scale. Single board computers are a niche in the market, with lower manufacturing frequency and higher cost.

The motherboard and SBC now provide similar levels of feature integration, which means that motherboard failures in either standard require equivalent replacement.