Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!emory!hubcap!ncrcae!ncr-sd!se-sd!cns!dltaylor From: dltaylor@cns.SanDiego.NCR.COM (Dan Taylor) Newsgroups: comp.sys.amiga.advocacy Subject: Re: Real Time UNIX (Re: NeXT software size) Message-ID: <947@cns.SanDiego.NCR.COM> Date: 8 May 91 20:49:17 GMT References: <1421@saltillo.cs.utexas.edu> <1991May6.112709.8280@sugar.hackercorp.com> <361@ncmicro.lonestar.org> Organization: NCR Corp. SE-San Diego Lines: 42 In <361@ncmicro.lonestar.org> ltf@ncmicro.lonestar.org (Lance Franklin) writes: >OS/9 is a Unix? I was under the impression that OS/9 was another real- >time OS with some Unix-like features (in the same way that the Amiga OS >is a real-time OS with some Unix-like features). While OS-9 is NOT a real-time UNIX, bsd sources DO seem to compile with little, if any modification (and run). Longer ago than I care to admit, I put umodem on an OS-9/68K, since kermit wasn't out, yet. OS-9 does use volumes, like AmigaDOS (and VMS.... just about everybody but UNIX, I think), but at least "/" is the root of the volume (I HATE the person who made that the same as UNIX ".." under AmigaDOS ";-)"). Almost no one needs a real-time UNIX, although some applications would be a bit more robust, under it. Snappy, reliable I/O is a MUST, though. It is inexcusable to drop characters, even at 38400, on any baud rate supported by the driver, for instance. What are nice about OS-9 and AmigaDOS are the rapid user response, IMHO, and the small code sizes for common applications. AmigaDOS has almost no features in common with any UNIX that I have used. There are some utilities with similar names, and functions. Most compiler vendors have included UNIX-style library routines (over and above the C standard library functions), but the OS, itself, is not terribly like UNIX, for good, or ill. The file system is different, and for a personal computer, better with FFS. The IPC mechanisms are not quite same where they do overlap, and there are different sets. Scheduling is similar, in that both have prioritized round-robin, but the aging mech- anisms are different. The AmigaDOS, and OS-9, kernels are robust enough, and rich enough in features that UNIX-like functionality is supportable. AmigaDOS had shared libraries before UNIX, for instance. Given the grief that many of us suffered under 1.0 and 1.1, I wonder if we wouldn't have been better off with C= buying OS-9/68K, which was reasonably stable, at the time, then adding the part of AmigaDOS that really shines, Intuition, and the support for the graphics chips, as Microware has added graphics support to OS-9, finally. Please, no flames, it's just an idle thought. Dan Taylor