X.21 {Out-dated interface}

X-Bus: {A four wire bus based on RS-485. Two wires for data, and two wires for power. Obsolete}

X-by-Wire Bus {vehicle Bus.}

XGA [Extended Graphics Array]: {IBM introduced the XGA video interface as a successor to its 8514/A display in 1990.}

XGMII (10 Gigabit Media Independent Interface. Uses SSTL_2 interface levels. provides an optional interconnection between the Media Access Control (MAC) sublayer and the Physical layer (PHY) of 10 Gigabit Ethernet.}

XSBI (10-Gb Sixteen Bit Interface}

XTX (eXtended Technology ETX) with a form factor of: 95mm x 111.6mm (5.75 x 8 inches). XTX is an Embedded computer board standard, an extension of the ETX board. XTX is a board standard, not a bus standard. XTX removes the ISA interface on the X2 connector [used on ETX] and replaces it with PCIe, SATA, USB .... interfaces}

XAUI (Ten Attachment Unit Interface}

Next Section Electronic Buses 'Y'

An alphabetic listing of released interface buses. Primarily the links point to pages that describe the physical and electrical interfaces. Interface Bus protocols are not addressed.