A single-board computer (SBC) comprise a complete device possessing the functions of a computer, designed in the form of a printing board with a processor, RAM , storage, and input-output devices.
Most single-board computers differ from processor boards used in desktop (office) systems with availability of support of special input-output interfaces such as ISA, PCI, PCI-E, PCI-X, serial interfaces (RS 232, RS 422, RS 485). As a rule, many SBCs have additional interfaces for connection of discrete and analogous signals.
There exist a great deal of single-board computer form factors, which often determine their dimensions and functionality (standards — COM express, QSeven, SMARC, PC 104, EPIC, EBC, 3,5″, Pico-ITX, mini-ITX, PICMG 1.0, PICMG 1.3 etc.).
Selection by manufacturers:
ADVANTECH AICSYS ADLINK B-PLUS EUROTECH PERFECTRON StackPC X-ES WINSYSTEMS