"Macintosh Quadra, Centris, PowerBook 500, Duo Dock II (for PowerBook Duo) and early Power Macintoshes have AAUI ports, which require external transceivers. By the time AAUI was nearing the end of its life, an AAUI transceiver could cost even more than an inexpensive Ethernet card on a PC—a disproportionate amount—as network cards for PCs did not become commodity items until the spread of high-speed access to the Internet in the early 21st century. Later models include both AAUI and 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 and Performa machines. AAUI had disappeared by the late 1990s, when new Apple machines, starting with the beige Power Macintosh G3 series, include RJ-45 jacks instead of both"