Operating system (OS) is a master program that controls the functioning of the computer hardware; it is an interface linking the user and the hardware. Normally, an operating system executes processes through application software. There are many categories of application software, including business software, education software, entertainment software, and utility software. Application software depends on the operating system installed in a computer or a Personal Digital Assistant (PDA).
There are many operating systems such as the single-user OS, multi-user OS, and PDA OS. A single-user OS is mostly used on desktops and laptops. They include Microsoft Windows and Apple MacOS platforms. A multi-user OS allows many users to use computer resources at the same time. UNIX and mainframe OS are examples of multi-user OS (Stallings, 2005).
According to Lubomir & Chaw (2003), in a multi-user OS, many users access connected computer resources remotely through a terminal. When a person from a network computer wants to print a document, the task is sent to a queue; the OS keeps the print tasks organized and allows each task to be printed one at a time. In a single-user multitasking OS, a user can perform many tasks at the same time. For example, printing, editing, playing music, and accessing the Internet.
A multi-user operating system differs from a single-user system, in that each user accesses an operating system in the main computer in different places, where the operating system handles each task sent by the concurrent users. It also ensures that a user does not obstruct other tasks from other computers in the network as compared to the single-user multitasking system where the operating system handles the requests of only one person. There are two types of multitasking systems: one is preemptive and cooperative, where the preemptive gives out the central processing unit in slices, and time is given to each program – for example Windows NT and Windows 95; and in supportive multitasking, the CPU can be managed by each program – for example, Microsoft Windows 3.x.
Stallings (2005) asserts that there are two types of the single-user operating system: the single-task operating system and the single multitasking operating system. Although a single user OS can be connected to other systems in the network, it is only used by one person as compared to the multi-user which has many users. Other computers can access data from the computer but are not able to run programs on the single-user computer as compared to the multi-user system which enables the users to run applications on other computers. A single-user system is developed on a computer that will only run one application at a time. It is not useful for a computer intended to run many programs at once.
On the other hand, PDA OS is a type of operating system which has replaced the conventional organizer due to its many features like an immediate response to switching from one application to another and synchronization operations. These operating systems include Windows CE, Palm OS, and Symbian OS. Windows CE is used in wireless and personal devices, Palm OS is used for handheld devices, and Symbian OS is used in portable and mobile devices. All these operating systems are used in wireless information devices. With the Wireless information device, devices are usually small and are occasionally connected – they can be used on a wireless mobile phone or other networks.
The Palm OS uses multitasking, but only one task at a time as compared to the single-user and multi-user operating systems. One task must finish before the next can be executed. This allows the operating system to fully complete a task with the application that is open. The space for the applications is dynamic and the memory is accessed randomly. Palm operating system uses a pen to input data as compared to multi-user and single-user systems, which use a keyboard. Thus, Pam is effective in executing few tasks required by small business (Cooper, 2008).
Choffness and Deitel (2006) affirm that Windows CE, also called Windows Mobile OS, has increased strings of priority level. It has more management of time and scheduling; applications can control the time given to each thread and can manipulate the scheduler as compared to single-user and multi-user system, which are not able to handle time management and scheduling. It has improved method of handling priority inversion with full support of cased interrupts and memory management. Cooper (2008) asserts that Windows Mobile is used in many commercial applications because of its complexity.
The Symbian operating system is used in mobile phones and other information services. It is an advanced multitasking operating system that supports a pen based graphical user interface as compared to the other multitasking operating systems. Hansen (2001) conforms that Symbian has many features, including comprehensive assimilation of information, messaging, use of the Internet, and wireless services. It comes with an application suite which contains word processer, email handler, scheduling application, database, communication programs, and a web browser. Moreover, it has a keyboard and a pen input.
In this light, PDA has replaced the usual organizer. This has helped in assisting users or companies with daily activities because it has improved its software capabilities and hardware processor speed, screen resolution, and memory. PDA is widely used in cellular phones and digital cameras. Therefore, companies using multi-user or single-user operating systems should consider using PDA OS which has many features. For example, Symbian for phone organizers, Palm for personal information devices and markets, and Windows Mobile for commercial purposes to improve speed, productivity, and efficiency.
References
Choffnes, D. R., Deitel, H. M., & Deitel, P. (2006). Operating Systems. New Jersey: Prentice Hall.
Cooper, R. (2008). PDA Operating Systems. Web.
Hansen, P. B. (2001). Classic Operating Systems. New York: Elsevier, Academic Press.
Lubomir, F. & Chaw, A. (2003). Operating Systems. New Jersey: Prentice Hall.
Stallings, W. (2005). Operating Systems, Internals and Design Principles. Upper Saddle River, NJ: Prentice-Hall, Inc.,