What are some good reasons for designing  operating system as a layered OS? Why isn’t MS-DOS an example?
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ms dos does not support multi tasking........in the case of layered os u can have mutlty task envoirment
1017724
I would assume the top level is the computer system's operating system. There is nothing higher. It did cross my mind that a network of systems is higher, but then a network is considered a structure within the system. When designing a top-down model, the highest and top-most design is always the whole system, paper, computer or whatever. However, as concepts and operating systems develop, I'd assume the application is the highest, with accessible operating system objects a structure withing the application. The reason being the operating system treats each application as a stand-alone program with its own memory space and so on. Should anything crash, it is this protected enclosure of a sandbox land that is effected, not the system as a whole.
98158
OOP languages have extra language features - e.g. encapsulation, polymorphism, and inheritance are object behaviours that don't have a direct procedural equivalent.\n\nFor making setup files, there are commercial solutions like InstallShield, but for free, consider NSIS: http://nsis.sourceforge.net/Main_Page
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Most computer users use the Windows operating system. But in today’s scenario where open source software has started playing a major role in bringing out Linux based distributions, many experienced computer users are either moving to Linux or would like the option.\n\nFor years, Linux supporters have touted the open-source operating system as a less-expensive, more reliable alternative to Unix and Windows running on x86 based, or industry-standard servers.\n\nA thorough change is taking place, resulting in more and more usage of Open source software.  Most importantly, this beneficial change is happening in significant numbers through out the world.\n\nWHY SWITCH OVER? \n\nThe switch over is mainly because of the following two reasons:\nCost savings\nFreedom from licensing dominance\n\nDue to these reasons, more and more companies today are migrating to Linux from other Operating Systems than ever before.\n\nPROS:\nLinux Is Free\nLinux Is Portable To Any Hardware Platform\nLinux Was Made To Keep On Running\nLinux Is Scalable\n\nMAJOR DIFFERENCES:\n\nLinux: Linux is free\nWindows: MS Windows costs money\n\nLinux: In this case people are unlikely to violate any License agreement, all the software is happily yours\nWindows: In this case people likely already violate all kinds of licenses\n\nLinux: Linux is built for more sophisticated, feature hungry computer users\nWindows: MS Windows tries to be the "lowest-common-denominator" operating system\n\nLinux: Linux is based on UNIX \nWindows: Windows is based on DOS\n\nLinux: Linux GUI is based on industry-standard X Windows\nWindows: Windows Graphical User Interface (GUI) is based on Microsoft-own specifications\n\nLinux: Linux beats Windows hands down on network features, and as a development platform\nWindows: MS Windows desktop has a more polished appearance
353009
Why? I run Linux. If I'm going to get a free OS I'll get the superior one, thanks.
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Actually any program that could do this would be considered to have an embedded operating system. Many antivirus and system recovery programs use a minimized o/s in order to access the hard drive.
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One can only functionally position the internet model to the ISO OSI model because basic differences exist such as: \n\nIn the internet protocol suite, a layer represents a reasonable packaging of function. \nThe ISO view, on the other hand, treats layers as rather narrow functional groups, attempting to force modularity by requiring additional layers for additional functions. \n\nIn the TCP/IP protocols, a given protocol can be used by other protocols within the same layer, whereas in the OSI model two separate layers would be defined in such circumstances. Examples of such "horizontal dependencies" are FTP, which uses the same common representation as TELNET on the "application layer," and ICMP, which uses IP for sending its datagrams on the "internetwork" layer. \n\nIn practice, what we are discussing here is the difference between a de jure standard, OSI, and a de facto standard, TCP/IP. The focus in the TCP/IP world is on agreeing on a protocol standard which can be made to work in diverse heterogeneous networks. The focus in the OSI world has always been more on the standard than the implementation of the standard. \n\nEfficiency and feasibility. The OSI norms tend to be prescriptive (for instance the "layer N" must go through "all layers below it"), whereas the TCP/IP protocols are descriptive, and leave a maximum of freedom for the implementers. One of the advantages of the TCP/IP approach is that each particular implementation can use operating system-dependent features, generally resulting in a greater efficiency (fewer CPU cycles, more throughput for similar functions), while still ensuring "interoperability" with other implementations. \nAnother way to see this is that most of the internet protocols have first been developed (coded and tested), before being "described" in an RFC (usually by the implementer) which clearly shows the feasibility of the protocols. \n\n2.14.2 The Internet World and OSI \nThe Department of Defense (DoD), funder of the original ARPANET research, made a statement on OSI in January '88, based on the Government OSI Profile (GOSIP) of April 22, 1987. \n\nThe following is an excerpt from the statement, which is published in RFC 1039 - A DoD Statement on OSI: "... It is intended to adopt the OSI protocols as a full co-standard with the DoD protocols when GOSIP is formally approved as a Federal Information Processing Standard. Two years thereafter, the OSI protocols would become the sole mandatory interoperable protocol suite; however, a capability for interoperation with DoD protocols would be provided for the expected life of systems supporting the DoD protocols. ..." \n\nA lot of study has already been done by the internet world on possible transitions and coexistence of the protocols. The following list is a series of RFCs already issued for that purpose: \n\nRFC 983 - ISO Transport Services on Top of the TCP. \nRFC 1006 - ISO Transport Services on Top of the TCP - Version 3. \nRFC 1039 - A DoD Statement on Open Systems Interconnection Protocols. \nRFC 1069 - Guidelines for the Use of Internet IP Addresses in the ISO Connectionless-Mode Network Protocol. \nRFC 1085 - ISO Presentation Services on Top of the TCP/IP-based Internets. \nRFC 1086 - ISO-TP0 Bridge between TCP and X.25. \nRFC 1090 - SMTP on X.25. \nRFC 1161 - SNMP over OSI. \nRFC 1195 - Use of OSI IS-IS for Routing in TCP/IP and Dual Environments. \nRFC 1238 - CLNS MIB for Use with Connectionless Network Protocol (ISO 8473) and End System to Intermediate System (ISO 9542). \nRFC 1240 - OSI Connectionless Transport Services on top of UDP: Version 1. \nRFC 1308 - Executive Introduction to Directory Services using the X.500 Protocol. \nRFC 1309 - Technical Overview of Directory Services using the X.500 Protocol. \nRFC 1327 - Mapping between X.400 (1988)/ISO 10021 and RFC 822. \nRFC 1328 - X.400 1988 to 1984 Downgrading. \nRFC 1330 - ESCC X.500/X.400 Tas
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much with care\nANN compliments DSS. make things more easy ya but sophsicated. nanotachnology and enhanced processor desuigning make possible. Things resolves faster using less system resources.TAT is less
482191
Both are operating systems, but owned and priced differntly. Windows is a Dos based, Microsoft owned platform. It is most widely used, and it's source code is owned by Microsoft, who keeps upgrading it over time. This is not a free software, and comes on licence to use basis. MS also provides regular support and upgrades. Most developers develop new software to be first compatible with Windows.\nLinux, is a Unix based OS. Unlike Windows, it is not owned by anyone. The source code is free, and freelancers develop it to make it better. Some companies sell a version to cover the support cost, but mostly it is available free to download and install. It has limited product support and upgrade support, but being on Unix, is more safer when it comes to virus attacks etc. More companies are switching to Linux now, for these reasons.
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In traditional Dos based systems it is a simple matter of including relevant assembly code in C language. May not be so easy if you are in applicaton mode on other operating systems. Not very difficult, need to know assembly language if you want to directly manipulate, other you can use operating system routines to access it (if your program resides within the kernel).
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i think you be asking about the new operating system ubuntu. I install and use this OS on my PC and i find it to be a user friendly and a good combination of many embedded software.i still dont use it for networks i find it to be a good OS for a home user.
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operating system\n\nAn operating system (OS) is a computer program that manages the hardware and software resources of a computer. At the foundation of all system software, the OS performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating networking, and managing files. It also may provide a graphical user interface for higher level functions.
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you're kidding right?\n\nSoftware.\n\nHardware is everything tangible. An OS is a medium for hardware and application to communicate.
1042015
MS-DOS was an early MicroSoft operating system used before Windows came along.  Limited grapics, mainly manual commands.\n\nThe Command Line is a DOS Emulator used in the Windows Operating System.  Many of the commands are the same, but some are not.
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Because it's impossible without Microsoft releasing its source code. You can't run a program compiled for one kernel on another.
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There's a history here to help you with your research:\n\nhttp://en.wikipedia.org/wiki/Operating_system
1082008
MS-DOS was way better than windows. Everything was easy to do and easy to find. And the old computers of the time running DOS ran faster than todays computers running XP