Editing Apple Attachment Unit Interface (section)

==FriendlyNet==
AAUI is part of a system of Ethernet peripherals intended to make connecting over Ethernet easier. At the time of the introduction of AAUI, Ethernet systems usually were [[10BASE2]], also known as thinnet. Apple's system is called FriendlyNet. A FriendlyNet 10BASE2 system does not use BNC T-connectors or separate {{val|50|ul=Ω}} [[Electrical termination|terminators]]. Instead of a single [[BNC connector]] that is inserted into a T-connector placed inline, the FriendlyNet transceiver has two BNC connectors, one on each side, to which the cables are attached. The transceiver automatically terminates the [[Computer network|network]] if a cable is missing from either side. Additionally, Apple 10BASE2 cables terminate the network when no device is attached to them. Thus the number of mistakes that could be made hooking up a thinnet network is reduced considerably. Since any of these mistakes can disable the network segment, this presents a significant improvement.

FriendlyNet equipment was expensive. Because of this, Apple's computers, billed as having built-in Ethernet, were expensive to connect to Ethernet, perhaps adding as much as a tenth to the total price of the computer system. Additionally, AAUI held no advantage for any system other than 10BASE2, and thus as 10BASE-T became ubiquitous it became impossible to justify the cost of an external transceiver. Apple eventually abandoned the system and sold off the name.

[[Macintosh Quadra]], [[Macintosh Centris|Centris]], [[PowerBook 500]], [[PowerBook Duo|Duo Dock II (for PowerBook Duo)]] and early [[Power Macintosh]]es have AAUI ports, which require external transceivers. By the time AAUI was nearing the end of its life, the cost of an AAUI transceiver became a burden for consumers. Later models include both AAUI and [[8P8C|modular connector]] ports for directly connecting 10BASE-T; either can be used, but not both at the same time. AAUI connectors are also present on some [[Processor Direct Slot]] Ethernet adapter cards used in [[Macintosh LC family|Macintosh LC]] and [[Performa]] machines. AAUI had disappeared by the late 1990s, when new Apple machines, starting with the beige [[Power Macintosh G3]] series, include only the modular connector ports.