PC/104 is a family of embedded computer standards which define both form factors and computer buses by the PC/104 Consortium. Its name derives from the 104 pins on the interboard connector (ISA) in the original PC/104 specification and has been retained in subsequent revisions, despite changes to connectors. 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.

Specification Bus Communication
PC/104 ISA (AT and XT)
PC/104-Plus ISA and PCI
PCI/104-Express and PCIe/104    PCI and PCI Express