was running. An RS-232C interface was provided to which a terminal could be attached. Extensive diagnostics could then be run in conjunction with special microcode to perform fault analysis in the event of a system failure. Problems could usually be isolated to one or two integrated circuits. One or more intelligent I/O channels controlled peripheral activity. Each of these included a full function microcomputer based around the Z80 which performed control functions and housekeeping. Data transfers to and from peripheral devices took place via a direct memory access (DMA) path itself constructed using Am2901 bit-slice microprocessors. This allowed the full performance of the Orion memory system and of the peripheral device to be exploited, with the microcomputer able to take corrective action on soft I/O errors. Software on the Orion communicated with the microcomputer using a high level message passing protocol. Operating system The operating system for the microcodable Orion was OTS (Orion Time Sharing) version 1.x, a port of the 4.1BSD UNIX operating system. The Clipper-powered Orions ran OTS version 2.x, a port of the 4.2BSD UNIX with some additions. This was not notably reliable or secure, and had a tendency to 'forget' process user IDs, randomly leaving user processes running as root. HLH also produced a graphics terminal for the Orion called the StarPoint, to which they ported the X Window System. The Orion series was moderately popular with the computer science departments of British universities, including Westfield College, London, Bath, Edinburgh, Heriot-Watt, Kent, Southampton, Warwick, York, King's College, London. A typical multi-user Orion configuration would have had 8 MB of RAM, an SMD hard disk (e.g. a 168 MB Kennedy or a 434 MB Fujitsu Eagle), a 60 MB QIC-24 tape drive and 8 to 32 RS-232 terminal ports. References Bibliography Orion, A High Performance Personal Computer - Sales brochure produced by High Level Hardware Limited. Orion 1/05 - Sales brochure produced by High Level Hardware Limited. Orion Configuration Guide - Product information produced by High Level Hardware Limited. Fiedler, S. "Hunting for High Performance with Orion." Unique, The UNIX System Information Source. 7.9 (1989): 11-12. Print. External links Photo of an HLH Orion at Bath University An original Orion upgraded to an Orion 1/05 in the Jim Austin Computer Collection Minicomputers 32-bit computers Computers using bit-slice designs