Apollo/Domain was a range of workstations developed and produced by Apollo Computer from circa 1980 to 1989. The machines were built around the Motorola 68k family of processors, except for the DN10000, which had from one to four of Apollo's RISC processors, named PRISM.
The original operating system was Apollo's own product called Aegis, which was later renamed to Domain/OS. The Aegis and Domain/OS system offered advanced features for the time, for example an object oriented filesystem, network transparency, diskless booting, a graphical user interface and, in Domain/OS, interoperability with BSD, System V and POSIX.
An Apollo workstation resembled a modern PC, with base unit, keyboard, mouse, and screen. Early models were housed in short (about 2 ft high) 19" rack cabinets that would be set beside a desk or under a table. The DN300 and later DN330 were designed as integrated units with system and monitor in one unit and fit easily on a desk. Every Apollo system (even standalones) had to include at least one network interface. Originally the only option was the 12 Mbit/s Apollo Token Ring (ATR). Over time, 10 Mbit/s Ethernet was added as an option. It has been stated that the IBM Token Ring was an option - this was never available. The ATR was generally the best choice, since it was extremely scalable; whilst the Ethernet of the time suffered serious performance loss as extra machines were added to the network, this was not true of ATR, which could easily have over a hundred machines on one network. One drawback was that, unlike Ethernet, one machine failure (which could easily happen given a single faulty connector) stopped the entire network. For this reason, Apollo provided an optional (but strongly recommended) network cabling system of bypass switches and quick connect boxes which allowed machines to be disconnected and moved without problems. Apollo Token Ring networks used 75 ohm RG-6U coaxial cabling.