Tim King, AmigaDOS royalty, dies aged 70

OBIT Dr Timothy James King, the programmer behind the 68000 version of TRIPOS that became AmigaDOS, has died aged 70. According to an AmigaNews report, King's family said he passed at the end of July. King was a superb programmer – although he accomplished rather more than that. His most widely experienced work was a key component of the original Commodore Amiga's operating system. His port of Cambridge University's TRIPOS OS to the Motorola 68000 CPU became AmigaDOS. His rapid work getting it running on prototype Amiga hardware helped Commodore launch the machine in 1985 after its in-house OS project failed to deliver. As he put it himself: "As a result I have the distinction of having written software used by over 2 million users." TRIPOS is not well known today, although its Wikipedia article provides a useful overview. King did not create TRIPOS: it was written by Cambridge boffin Dr Martin Richards. TRIPOS was written in the BCPL programming language, which Richards also created. The first recorded "hello, world" example was written in BCPL, which was also used to develop software for the Xerox Alto. Today, however, it is mostly known as the immediate ancestor of the C programming language. This page of scans from Australian Personal Computer magazine gives a good description of TRIPOS. While a researcher at the University of Bath, King ported TRIPOS from the DEC PDP-11 to the new Motorola 68000 CPU. His next job was at Bristol-based 68000 development tools specialist MetaComCo. For that company, he adapted his new 68K version of TRIPOS to the SAGE IV machines that MetaComCo used. Meanwhile, Commodore was developing the Amiga in the US, but its in-house operating system for the new hardware, known as CAOS, was badly behind schedule. Commodore went looking for outside help, and it approached MetaComCo, as this Nosher.net potted history documents. King not only ported TRIPOS to the prototype Amiga hardware, but also integrated the BCPL-based portion with Carl Sassenrath's existing Amiga Exec kernel and the Intuition windowing system. King's contribution substantially influenced the AmigaDOS command line, filesystem, and command structure, as this comparison of the TRIPOS and AmigaDOS manuals demonstrates. We highly recommend this 2022 interview, in which he praises "Exec," whose message-passing design fitted TRIPOS well. In his history of CAOS, Amiga "Wizard Extraordinaire" Andy Finkel said: "What we now call AmigaDOS was really the backup DOS, based on an already existing OS known as Tripos (developed at the University of Cambridge Computer Laboratory by the TRIPOS Research Group, and converted with amazing speed by Metacomco's Dr. Tim King and his band of programmers)." The BCPL code was rewritten in C for AmigaOS 2, but King was not worried: he had already moved on. He joined Perihelion, a startup created by the late Jack Lang. Lang would go on to co-found the Raspberry Pi Foundation with Eben Upton – whose PhD supervisor was the very same Martin Richards. At Perihelion, King worked on parallel processing systems, notably the Transputer from David May's INMOS. INMOS intended Transputer software to be written in its unique Occam programming language, which implemented the Communicating Sequential Processes model created by the late Professor Tony Hoare. This was unfamiliar to developers accustomed to Unix and C, so King drew on ideas from TRIPOS to create Helios, a parallel, cluster-scale, Unix-like OS for machines built from multiple INMOS Transputer chips. Helios-NG is still around as open source: we wrote about it in 2021, and we covered some of the history back then. Neither the Transputer nor Helios became a major commercial success, so King turned his attention elsewhere. Spotting the rapid growth of commercial internet connectivity, he founded early British ISP UK Online in 1994. He sold it to Easynet in 1996, and it continued as a brand until parent company Sky shut it down in 2011. King subsequently described himself as a "technical consultant" – first with "outsourcing colossus CSC," then through TJJ Ltd, the consulting company he ran with his wife and business partner, Jessica. There are some touching tributes in various Amiga communities around the internet, including Reddit /r/amiga and on Hacker News. Both have some contributions from former co-workers. ®