PC104 is a family of embedded computer standards which define both form factors and computer buses. PC/104 is intended for specialized environments where a small, rugged computer system is required. The standard is modular, and allows consumers to stack together boards from a variety of COTS manufacturers to produce a customized embedded system.
PC-104The original PC/104 PC motherboard IS at the size of 3.550 × 3.775 inches (90 × 96 mm). PC/104 boards are stacked on top of each other like building blocks. The PC/104 specification defines four mounting holes at the corners of each module, which allow the boards to be fastened to each other using standoffs. The stackable bus connectors and the standoffs provide a more rugged mounting than slot boards found in desktop PCs. The compact board size further contributes to the ruggedness of the form factor by reducing the possibility of PCB flexing under shock and vibration.