A Medium Attachment Unit is a transceiver which converts signals on an Ethernet cable to and from Attachment Unit Interface signals.
A thicknet MAU. The vampire tap is shown with a piece of yellow coaxial cable (cut off on either side of the tap) of the type used for 10BASE5 Ethernet.
A thinnet MAU, showing a single BNC and a DA15 connector
Two Medium Attachment Units (MAUs). The units shown are backwards-compatibility–oriented 10BASE-T MAUs, not older 10BASE5 or 10BASE2 MAUs.
A collection of old Ethernet equipment. At the top of the image, from left to right: A thinnet MAU with passthrough BNC connectors and a DA15 connector, a thicknet MAU with passthrough N connectors and a DA15 connector, and an AUI cable for connection of an MAU to the DA15 port.
The Attachment Unit Interface is a physical and logical interface defined in the IEEE 802.3 standard for 10BASE5 Ethernet and the earlier DIX standard. The physical interface consists of a 15-pin D-su
Medium Attachment Unit
…A Medium Attachment Unit (MAU) is a transceiver which converts signals on an Ethernet cable to and from Attachment Unit Interface (AUI) signals. On original 10BASE5 (thicknet) Ethernet equipment, the MAU was typically clamped to the Ethernet wire via a vampire tap and connected…
AUI Connectors. The male connector (left) is on the MAU, and the female connector (right) is on the DTE device (typically either a computer or an Ethernet hub). Note the sliding clip.
AUI Connector with numbered pins on the DEC EtherWorks LC (DE100) Ethernet controller. Note the jackposts (as opposed to a sliding clip).