text: Market ARCNET remained proprietary until the early-to-mid 1980s. This did not cause concern at the time, as most network architectures were proprietary. The move to non-proprietary, open systems began as a response to the dominance of International Business Machines (IBM) and its Systems Network Architecture (SNA). In 1979, the Open Systems Interconnection Reference Model (OSI model) was published. Then, in 1980, Digital, Intel and Xerox (the DIX consortium) published an open standard for Ethernet that was soon adopted as the basis of standardization by the IEEE and the ISO. IBM responded by proposing Token Ring as an alternative to Ethernet but kept such tight control over standardization that competitors were wary of using it. ARCNET was less expensive than either, more reliable, more flexible, and by the late 1980s it had a market share about equal to that of Ethernet.  Tandy/Radio Shack offered ARCNET as an application and file sharing medium for their TRS-80 Model II, Model 12, Model 16, Tandy 6000, Tandy 2000, Tandy 1000 and Tandy 1200 computer models. There were also hooks in the Model 4P's ROM to boot from an ARCNET network.
  When Ethernet moved from co-axial cable to twisted pair and an "interconnected stars" cabling topology based on active hubs, it became much more attractive. Easier cabling, combined with the greater raw speed of Ethernet (, as compared with  for ARCnet) helped to increase Ethernet demand, and as more companies entered the market the price of Ethernet started to fall—and ARCNET (and Token Ring) volumes tapered off.
  ARCnet Plus and decline
  In response to greater bandwidth needs, and the challenge of Ethernet, a new standard called ARCnet Plus was developed by Datapoint, and introduced in 1992. ARCnet Plus ran at , and was backward compatible with original ARCnet equipment. However, by the time ARCnet Plus products were ready for the market, Ethernet had captured the majority of the network market, and there was little incentive for users to move back to ARCnet. As a result, very few ARCnet Plus products were ever produced. Those that were built, mainly by Datapoint, were expensive, and hard to find.