Message-ID: <000601c16147$62db5c40$027efea9@atlantis> From: "Matthias Paul" To: References: <200110290041 DOT f9T0fn1g012179 AT eos DOT arc DOT nasa DOT gov> Subject: Re: rx and free dos? Date: Tue, 30 Oct 2001 14:29:58 +0100 Organization: University of Technology, RWTH Aachen, Germany MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MIMEOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id f9UDX6a05651 Reply-To: opendos AT delorie DOT com On 2001-10-29, Jim Stevenson wrote: > What is the difference between rx and free dos? Everything - except for the fact that both are open sourced, and both are hosted at http://www.freedos.org. Api Software´s RxDOS is a DOS work-alike developed by Mike Podanoffsky (not Mark, sorry for my confusion) with some focus on real-time applications in mind and consists of a kernel and a rudimentary shell, no utilities. AFAIK, recent versions support long filenames (and FAT32???), but I have no personal experience with this DOS issue. It does not implement all DOS functions and I assume that it is by far not as DOS compatible as DR-DOS is. Most parts of FreeDOS (current version is Beta 7) are written in C to provide some form of platform independence. However, this might have made sense for a simple DOS API work-alike for specialized embedded systems applications which was the original intention for the predecessor of the FreeDOS kernel, DOS-C. But IMHO it does not make sense for a general purpose DOS, which must run /existing/ DOS applications of the last two decades. Without virtualization, these applications will only work on industry standard PC architecture machines, anyway, so programming the kernel in C has significant disadvantages. Although the FreeDOS kernel does not implement all DOS functions yet, it already consumes more memory than a kernel written in assembler and aggressively optimized for the x86 target platform (like the DR-DOS kernel). FreeDOS has made great progress during the past months, but compatibility and stability is still limited and in no way comparable with DR-DOS yet. DOS may be a seemingly trivial operating system by today standards, but for its memory size it has an impressive complexity, especially because of the existance of many undocumented aspects, which make it so difficult to develop a 100% compatible solution and add enhancements without breaking some applications. FreeDOS comes with many utilities from various origins, some few are already very powerful and mature (for example Brian E. Reifsnyder´s FDISK), but I´m afraid, most tools are still in their very early stages and don´t meet professional level software standards yet. However, if you can live with the rather inhomogene design of the various tools, and are not afraid of kernel bugs and the often different behaviour compared to MS-DOS/PC DOS or DR-DOS, then give FreeDOS a try. Some kernels already provide limited support for FAT32. Mind, that the bugs can only be squashed when people are /using/ the kernel and report the problems. Nothing for production systems, though... In my personal opinion, DR-DOS would be a much better thing to start with, but in the current situation FreeDOS has one big advantage: It is still being actively developed and supported, so it has a future, while DR-DOS has not unless Lineo would develop a new sense of responsibility and have an understanding in how the model works and publish the sources, so that we can take over development and - I´m sure - could soon provide very significantly enhanced source and binary distributions... It´s a real pity... Matthias -- Matthias Paul, Ubierstrasse 28, D-50321 Bruehl, Germany ; http://www.uni-bonn.de/~uzs180/mpdokeng.html; http://mpaul.drdos.org