MULTIPROGRAMMING AND TIME-SHARING ENVIRONMENT

In a multiprogramming and time sharing environment, several users share the system simultaneously. In this environment, the users have a chance to see the files or the program made by other user. But having this kind of environment also has a disadvantages or it may result in various security problems.

One of the security problems that may occurred is stealing or copying one’s programs or data. In time sharing environment we can’t avoid this kind of problem because as stated above users share the system at the same time. This kind of environment also is free and open to all. So everyone really have a time and a chance to browse and open it. That’s why stealing or copying of data really happened. There are many ways in order to steal or to copy of other’s program. One is using system resources such as Central Processing Unit (CPU), memory, disk space, peripherals and using also Universal Serial Bus (USB). Another, writing over another program’s (belonging to another user or to the operating system) area in memory. The same with stealing or copying, using   system resources (CPU, disk space) without proper accounting. Writing over program’s can cause damage to the printer to mix output by sending data while some other user’s file is printing. After that, the user who did stealing and writing other’s program he/she can now modify the data. It means he/she can reduce the data and shorten the program in which it is more understandable and readable or he/ she may add the program.

Another security problem that might happened is some viruses may enter or attack since multiprogramming and time sharing environment share the system simultaneously. Most probably virus may occur because of its free and open environment. The virus will block the data especially in time of processing and sharing. Virus might be a cause of file’s or data’s damage. Using of resources might be also the reason why viruses is being entered or attacked in your data or files.

Those several security problems that the users encountered are just a part of having a multiprogramming and time sharing environment. In order to avoid those problems probably we should be watchful, careful, etc so that everything will not turn into nothing. 

Time shared machines are those machines that perform multiple tasks and sharing simultaneously. The users can do multiprogramming and shared it to others simultaneously while dedicated machine is a system that accepts one primary task at a time. When we talked about the security of the two, I say that a dedicated machine is more secured than time shared machine. Time shared machine is prone with different problems such as virus vulnerability and etc. compared to dedicated machine.

Can we ensure the same degree of security in a time shared machine as we have in dedicated machine? Probably not, since any protection scheme devised by a man can inevitably be broken by him, and more complex the scheme, the more difficult it is to feel confident of its correct implementation. Therefore, time shared and dedicated machine are not equal or they don’t have the same degree of security because both of them performs different tasks as well as the environment.

USEFULNESS OF HANDHELD COMPUTER IN THE FIELD OF WORK

A mobile device (also known as a handheld device, handheld computer or simply handheld) is a pocket sized computing device, typically having a display screen with touch input and/or a miniature keyboard. This device is being used in the field of work in different profession.

 One of them is the news reporters. In the field of reporting, using handheld computer is very important especially for writing stories and news for the newspaper. Handheld computer are very useful for them and has the advantage of working in any places. He/she can formulate ideas and story because he/she can bring this device anywhere. He/she can also do some editing anywhere and anytime so that his/her job will be finished in a short period of time. Handheld computer consumed a little space, it is small and yet a very effective workspace in which you can make your job almost anywhere. He/she may also use a handheld computer for sharing files to other reporter, making team works easy and have a better performance. Though some team members separated but still they may do the job as one because of this device. A reporter with a handheld computer has a big difference compared to other reporter who don’t have one because they can make their job easy and anywhere and they can make it in a short period of time. Another thing that handheld computer is helpful because you can use these for storing your work or stories as a part of the collection. Therefore, handheld computer brings big changes for the news reporter in order to serve the people and disseminates the right information in a fastest way.

Another is a doctor. Nowadays, computers are very essential in the field of medicine. Doctor has now using handheld computer like Personal Digital Assistant (PDA’s) for some purposes. They use this device for drug information and prescribing medicines or drugs. Using this device can improve the health-related safety, quality and efficiency of care. They also used for identifying patients in the hospital and access to patient specific medical information for used in diagnosis and care decisions. Using handheld computer can also lighter the works of the doctor because they can do their job in just a short period of time. They can prescribe medicines or drugs in a fastest way. Handheld computer is helpful for the patients because in just a couple of seconds or minutes you will get all the information you need. Doctor can now easily share information to other doctor. There’s also a possibility that they can cater more patients and their transaction become faster. Even the doctor is not in the hospital or in the clinic still they can entertained their patients through this device. Therefore, handheld computer contributes a lot for the doctor, it will increase their performance and they can do the job in a fastest way particularly in prescribing medicines or drugs and giving the rig

TYPES OF OPERATING SYSTEM AND THEIR EXAMPLE

BATCH SYSTEM – Open VMS Operating System

Open Virtual Memory System (Open VMS) is a high-end computer server operating system that runs on Virtual Address Extension (VAX), Alpha, Itanium-based families of computers. Open VMS is a multi-user, multi-processing virtual memory based system. It is a multi-user because more than one user can use the machine at a time. It was designed and developed to use in time-sharing, batch processing, real-time, and transaction processing. It has a high system availability that can distribute the system over multiple physical machines. Open VMS is not free or not open source software but the source listings are available on purchase. It has a graphical user interface with complete graphics support. It also includes a process priority system that allows for real-time processes to run smoothly. It has also a 32 bit, multi-tasking or more than one program can be run at a time. Because it has a high-end server OS, open VMS commercialized many features such as integrated computer networking, symmetrical, asymmetrical and NUMA multi-processing including clustering, integrated database features such as RMS and many more.

INTERACTIVE SYSTEM – UNIX Operating System

UNIX operating system is a computer operating system originally developed in 1969 by a group of AT and T employees at Bell Labs. These are widely used in servers, workstations, and mobile devices. UNIX was design to be portable because only the kernel written in assembler tools for program development a wide range of supports tools, multi-tasking, and multi-user in a time sharing configuration. UNIX are featured by several notions such as the usability of plain text for storage data, treating devices and various kinds of inter-process communication as files, a hierarchical file system, and the utilization of a huge number of small programs that can be strung together through the command line interpreter using pipes. It consists of numerous constituents that are packaged together which include the growth environment, documents,

libraries, portable, modifiable source code for all of these constituents. Compared to windows it is more stable and does not go down so therefore it consumed less administration and maintenance. Unlike windows, it has greater built-in security and permissions features. It possesses much greater processing power. UNIX OS is the leader in serving the web about 90%. It also consists of kernel, shell and utilities.

REAL TIME SYSTEM – LYNX Operating System 

Lynx OS RTOS also known as Lynx operating system is the world’s most powerful open-standards real time operating system. It is a UNIX-like real time operating system produced and developed by LynuxWorks. It features full POSIX performance, more recently and Linux compatibility. It is mostly used in real time embedded systems like in applications for avionics, aerospace, the military, industrial process control and telecommunications. LynxOS components are designed for absolute determinism. It means that the responding or interacting takes within a known period of time. It is closed source software so no one can use or see the code. ABI compatibility with system V.3 was added lo LynxOS. Predictable response times are ensured even if there is a presence of heavy input and output due to its kernel’s unique threading model which allows interrupt routines to be extremely short and fast. It also exhibits true linear scalability so that it stays unwaveringly deterministic even as the tasks it performs increase massively. Lynx OS is the most open hard real time operating system available today.

HYBRID SYSTEM – MeeGo Operating System

MeeGo is an operating system that blurs the line between a robust mobile phone operating system and a lightweight netbook operating system. Actually MeeGo is a hybrid of two operating systems. The first one is the Nokia’s Maemo which recently appeared in the N900 smart phone and the second is Intel’s Moblin that intended for netbooks.  They are both open-source and Linux-based same also with MeeGo. MeeGo is intended or used for advanced smartphones, tablets, netbooks, in-vehicle technology and even in televisions. It supports ARM architecture and X86 and Intel atom processor commonly found in advanced smartphones and etc.MeeGo is intended for a new operating system category that doesn’t yet have a name. MeeGo is a hybrid version of the Nokia Maemo and Intel’s Moblin operating system. Its platform will be

used as a life of smartphone and in the netbook in the future. It is also an open source, Linux-based. MeeGo is classified as an advanced operating system and it is convenient to use for a variety of avatars and of course the operating system on your desktop PCs, the OS on smartphones and tablet PCs.

EMBEDDED SYSTEM – INFERNO Operating System

Inferno is an operating system started at Bell Labs, but now it is developed and maintained by Vita Nuova Holdings as free and open software. It is a well-designed, economical operating system particularly suitable for use in networked devices such as advanced video telephones, hand-held devices, TV set-top boxes, and many other embedded applications. Inferno can run in native mode on an embedded system or in emulation mode under many different operating systems. Inferno can also run  native mode on various ARM, PowerPC, SPARC and x86 platforms but also 'hosted', under an existing operating system such as FreeBSD, Irix, Linux, MacOS X, Plan 9, and Solaris), again on various processor types. Inferno has many features in common with Plan 9. . Inferno also features an API for easily integrating Zoran’s industry-leading IPS print language interpreters, which have been optimized to take advantage of Quatro’s dual-core CPU and DSP.  Inferno is a compact operating system designed for building distributed and networked systems on a wide variety of devices and platforms. With many advanced and unique features, Inferno puts an unrivalled set of tools into your hands. Inferno can run as a user application on top of an existing operating system or as a stand alone operating system such as Linux, Windows NT and etc.

Inferno also runs as a plug-in under Internet Explorer version 4 and higher. It also offers full support for authenticated, encrypted connections using a certificate based user identification scheme and variety of algorithms that includes IDEA, DES, RC4, MD4, MD5 and SHA.

Inferno has a complete development environment, providing all the tools necessary for creating, testing and debugging the applications