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DOS-C started in 1988 as an experiment in writing device drivers in C for
Microsoft\'s MS-DOS. Both block and character device drivers were written,
along with special C data structures to match the MS-DOS request packet. It
was then recognized that using the same techniques, an operating system
could be written that would take advantage of the C language features and
would require much less time to develop than the traditional assembly
language techniques. Although UNIX had proven this earlier, it was not
tried with a traditional pc operating system.
At this time, a minimal operating system using the device drivers written
earlier along with a new 8086 interrupt API was developed. It was called
XDOS and proved to be a functional operating system. This new operating
system was used to develop booting techniques and a C library SDK was
developed for it.
XDOS enhancements were started in 1989 and MS-DOS was chosen as the new API.
A more advanced architecture was also developed. This included the use of
an IPL (intermediate program loader) to set up the operating environment
prior to loading the operating system itself and reentrant system calls
facilitating real-time applications. This version, know as NSS-DOS, was
completed and demonstrated in 1991. As a result of these demonstrations,
NSS was approached to supply source license for this operating system by a
major defense contractor. The only new requirement - it had to run on 68K
processors.
This presented a new challenge. Due to the MS-DOS model used for the API,
NSS-DOS relied heavily on a segmented architecture. To meet this challenge,
a major redesign of NSS-DOS was undertaken. New proprietary techniques were
developed that allowed the same source to be compiled on a variety of hosts
and with a wide range of compilers. This new version, DOS/NT, was the result o
of this new project. The kernel was redesigned as a micro kernel along with
logical separation of the filesystem, memory and task managers. A new DOS
API was designed along with a new DOS SDK to guarantee portability.
Additionally, all processor unique code was separated from the core
functions. The result is the highly portable operating system that DOS/NT
represents.
After a number of successful commercial applications, DOS/NT became part of
both dosemu and FreeDOS.
This version, DOS-C, is the subject of an upcoming book and is intended for
binary redistribution, free of any royalty. See the accompanying
license.txt file for details. If you have not received this file, contact
me at the address below and I will send a copy to you.
The DOS-C kernel is also the FreeDOS kernel. FreeDOS is a project designed
to provide an alternative to MS-DOS, PC-DOS and DR-DOS that is freely
available. See the FreeDOS manifesto for details.
MS-DOS is a trademark of Microsoft Corporation.
UNIX is a trademark of USL, Inc.
Author
------
Pat Villani (patv@iop.com)
Copyright
---------
(c) Copyright 1995 by Pasquale J. Villani
All Rights Reserved.
License
-------
See COPYING in DOS-C root directory for license.
$Header: C:/dos-c/doc/history.txv 1.3 29 Aug 1996 13:06:42 patv $
$Log: C:/dos-c/doc/history.txv $
Rev 1.3 29 Aug 1996 13:06:42 patv
Bug fixes for v0.91b
Rev 1.2 19 Feb 1996 3:08:18 patv
Updated for v0.91
Rev 1.1 01 Sep 1995 17:30:42 patv
First GPL release
Rev 1.0 05 Jul 1995 18:50:22 patv
Initial revision.
给大家学习之用
DOS操作系统源代码.rar
(420 KB, 下载次数: 4)
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