Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!uwvax!astroatc!prairie!dan From: dan@prairie.UUCP (Daniel M. Frank) Newsgroups: comp.misc,comp.unix.questions Subject: Re: QNX? Message-ID: <380@prairie.UUCP> Date: Thu, 1-Jan-87 23:09:19 EST Article-I.D.: prairie.380 Posted: Thu Jan 1 23:09:19 1987 Date-Received: Fri, 2-Jan-87 02:38:54 EST References: <335@csustan.UUCP> <375@xios.UUCP> Reply-To: dan@prairie.UUCP (Daniel M. Frank) Distribution: na Organization: Prairie Computing, Madison, Wisconsin Lines: 60 Keywords: UNIX system?, software, programming tools Xref: mnetor comp.misc:65 comp.unix.questions:504 In article <375@xios.UUCP> greg@xios.UUCP (Greg Franks) writes: >QNX is a real-time UNIX-LIKE system. I have no idea about its >capabilities. QNX is a descendent of Waterloo Port, which is itself a descendent of Thoth. It is a bit like Unix on the surface, but bears no real structural similarity to it. QNX has a very small kernel that handles clock interrupts and message passing. All important system functions, including device and file system handling, and even task dispatching and memory management, are dealt with by individual tasks, communicating with messages (there are some optimizations under the covers, but this is what it looks like to the user). This makes QNX unusually flexible. For example, while QNX has its own file system, based on linked extent allocation and using in-place directory information rather than inodes, the user may start up another task or tasks to manage alternate file systems. This other task sends a message to the primary administrator asking it to redirect messages about particular disks to the appropriate task. Application programs have little or no idea what kind of file system they are using; the same program may be reading files from a QNX file system and writing them to a DOS disk! Quantum added an ARCnet capability to QNX some time ago. Messages pass between nodes on the network, allowing applications to use file systems on other machines with no special setup required. The network operates almost totally transparently. Programs may be distributed across the network, communicating via messages. A name service facility helps programs find servers such as line printer spoolers or database systems. A sizable base of application software has grown up, although QNX is still found most often in use for real-time or semi-real-time dedicated systems in areas such as patient management (there is a 32-node system in beta test at a hospital), manufacturing, and robotics. The main language for the system is C, and there are tools such as lex and yacc, a full screen editor, and a symbolic debugger. Text processing, mail, and automatic telecommunications software are available, as is database and spreadsheet software. MS-DOS may be run as a task under QNX, and uses devices over the network if configured to do so. As an added advantage, QNX runs both on the 8088/8086 and the 80286. On the 286, it runs in protected mode. Programs are completely portable between the different processors. Thus, QNX is quite economical. Workstations may boot over the network. A typical configuration might include diskless 8088-based nodes with one or more 80286 or 80386 based file and boot servers. The previous poster indicated Quantum's address, I believe, so I won't duplicate that. Caveat: I am not now an employee or stockholder of Quantum, but I've done a very occasional piece of work for them, and have known them for a while. Take what I say with whatever salt you consider appropriate. -- Dan Frank uucp: ... uwvax!prairie!dan arpa: dan%caseus@spool.wisc.edu