other at a central point), and "active" star with "PhoneNet Star Controller" hub hardware. Apple's LocalTalk connectors didn't have a locking feature, so connectors could easily come loose, and the bus configuration resulted in any loose connector bringing down the whole network, and being hard to track down. PhoneNet RJ-11 connectors, on the other hand, snapped into place, and in a star configuration any wiring issue only affected one device, and problems were easy to pinpoint. PhoneNet's low cost, flexibility, and easy troubleshooting resulted in it being the dominant choice for Mac networks into the early 1990s. AppleTalk protocols also came to run over Ethernet (first coaxial and then twisted pair) and Token Ring physical layers, labeled by Apple as EtherTalk and TokenTalk, respectively. EtherTalk gradually became the dominant implementation method for AppleTalk as Ethernet became generally popular in the PC industry throughout the 1990s. Besides AppleTalk and TCP/IP, any Ethernet network could also simultaneously carry other protocols such as DECnet and IPX. Networking model Versions Cross-platform solutions When AppleTalk was first introduced, the dominant office computing platform was the PC compatible running MS-DOS. Apple introduced the AppleTalk PC Card in early 1987, allowing PCs to join AppleTalk networks and print to LaserWriter printers. A year later AppleShare PC was released, allowing PCs to access AppleShare file servers. The "TOPS Teleconnector" MS-DOS networking system over AppleTalk system enabled MS-DOS PCs to communicate over AppleTalk network hardware; it comprised an AppleTalk interface card for the PC and a suite of networking software allowing such functions as file, drive and printer sharing. As well as allowing the construction of a PC-only AppleTalk network, it allowed communication between PCs and Macs with TOPS software installed. (Macs without TOPS installed could use the same network but only to communicate with other Apple machines.) The Mac TOPS software did not match the quality of Apple's own either in ease of use or in robustness and freedom from crashes, but the DOS software was relatively simple to use in DOS terms, and was robust. The BSD and Linux operating systems support AppleTalk through an open source project called Netatalk, which implements the complete protocol suite and allows them to both act as native file or print servers for Macintosh computers, and print to LocalTalk printers over the network. The Windows Server operating systems supported AppleTalk starting with Windows NT and ending after Windows Server 2003. Miramar