Monday, June 10th, 2024 British operating systems, part two =================================== Besides RISC OS, there is another family of operating systems from Great Britain that is even closer to me: Sinclair QDOS and its successors. In 1984, Sinclair released the QL computer, which was intended for business use. It had a more powerful processor (68008 instead of Z80), a higher screen resolution (512x256, 4 colors), and a multitasking operating system. The QL was deliberately introduced a couple of weeks before the Macintosh, making it the first on the market among the Macintosh 128k /Atari ST /Amiga 1000 /Sinclair QL quartet. This, along with the effort to keep the price as low as possible, significantly influenced how the computer looked, not only in terms of hardware but especially in terms of the user interface. Mac and Atari ST prioritized mouse-controlled GUI over multitasking. Amiga 1000, which was the last of the four to arrive, had a mouse, windows, icons, and multitasking. The Sinclair QL had neither a mouse nor a nice GUI, but it had full preemptive multitasking, even though the entire QDOS operating system fits into a 48kB ROM. Compare this with single-task Atari TOS, which needed 192kB ROM, single-task Macintosh System Software, which had 64 kB ROM and still booted from a disk, or multi-task Amiga OS, which started with 256 kB ROM and also had its desktop on a disk. Tony Tebby, the main developer of the system, had previous experience with Unix workstations, and his goal was to create a machine with similar capabilities but without the need to work with a Unix shell and C programming language. He chose BASIC as the user interface, which was a de facto standard on 8-bit computers, but here it was significantly more capable and could be extended with new commands by simply loading their definitions into the system. QDOS starts with three "windows": at the bottom is the command line, where commands are entered and executed immediately, or if they start with a number, they are stored to be executed later using the RUN command. Above this are two other windows: the white one contains the listing of the currently entered program, and the red one contains the output from the running program. Everything is handled by I/O channels so everything can be redirected (to disk, tape, network, serial port), the size and border of windows can be changed from BASIC, new windows can be opened, their colors set, fonts changed, etc. Although QDOS is a multitasking OS, due to the limited memory of the original QL, the BASIC interpreter can only run once. Machine code tasks, however, can run as many as the memory can hold. The computer was shipped with an office suite from Psion, which included a word processor, spreadsheet, business graphics editor, and database. Users typically loaded all these programs into memory after turning on the computer, sometimes even multiple times depending on the number of documents they needed to work with, and then just switched between running tasks. Unfortunately Sinclair Research begun facing problems around the time the QL was released. The computer was announced with a promise of early sale long before it was ready, so deliveries began with delays, and the shipped units were not always fully functional. The company was also working on the C5 electric vehicle, which was a flop, and before the QL could consolidate and establish itself, the entire company was bought by the rival Amstrad, which immediately halted QL production to avoid competition with its own line of budget business computers, the PCW, much simpler (Z80, CP/M), albeit more expensive machines than the QL. Rights to the QDOS system and the QL computer were never transferred to anyone, so further development was in the hands of unofficial hardware producers and system reimplementations based on available documentation. One of these reimplementations was called Minerva ROM, which fixed a large number of bugs that weren't dealt with by Sinclair Research, significantly sped up most functions, and added some new functionality; for example, the OS can use two independent screens, that the QL had from the beginning, but the original QDOS could only use one of them. Minerva ROM runs both on clones that emerged after the QL, or it can be installed in the QL itself. To this day, in its latest version, it is the best system for the original, unmodified computer. The best QDOS reimplementation, if you are not limited by the original hardware, is SMSQ/E, developed independently by Tony Tebby for more modern hardware than the original QL (Atari ST, Q40, Q60, Q68, or at least QL with a turbo card). While it runs the QL software without any modifications and the interface looks fundamentally the same, it's a significantly enhanced system. SMSQ/E offers full multitasking, including the BASIC interpreter, dozens of new BASIC commands, command line history, support for multiple graphics modes (depending on the computer on which the system runs), etc. It also integrates the Pointer Environment, a mouse-controlled graphical interface with a desktop, windows, and other elements common on modern computers. Pointer Environment also exists as an extension for Minerva and QDOS, but here it is already included in the system[1]. Due to the small user community and the development being led by a few individuals for a long time, systems like SMSQ/E, Minerva, and even the original QDOS have many unique features. It took me quite a long time to learn to use this system, perhaps even longer than with Plan9. But once I understood the basic principles, I couldn't resist getting a couple of QLs, and I'm currently waiting for the completion of a new batch of the modern FPGA computer Q68 running SMSQ/E, in which I have one unit pre-ordered. What a shame that British operating systems do not rule the world! [1] gopher://i-logout.cz/I/phlog/posts/2024-06-10_smsqe_screenshot.png