Can also be used to add or edit existing records in the table. A Report is a database object used to display records from a table or a query in a summarized format. Macros: a set of repetitively used commands or actions stored together for easier reference. Name and explain three types of computer buses A bus is a parallel data communication path over which information is transferred a byte or word at a time.
The buses contain logic that the CPU controls. The name of the bus or its operation usually implies the type of signal it carries or method of operation. All computers use three types of basic buses. The name of the bus is generally determined by the type of signal it is carrying or the method of operation. We group the buses into three areas as you see them in their most common uses. They are as follows: I. Control bus II.
Data bus III. Address bus Control Bus The control bus is used by the CPU to direct and monitor the actions of the other functional areas of the computer. It is used to transmit a variety of individual signals read, write, interrupt, acknowledge, and so forth necessary to control and coordinate the operations of the computer.
The individual signals transmitted over these buses carry control signal from ALU to memory and from memory to ALU and then to the output unit.
Address Bus The address bus consists of all the signals necessary to define any of the possible memory address locations within the computer, or for modular memories any of the possible memory address locations within a module. An address is defined as a label, symbol, or other set of characters used to designate a location or register where information is stored. The width of the address bus determines the amount of memory that can be addressed.
This explains the 4 GB memory restriction on bit operating systems. Data Bus The bidirectional data bus, sometimes called the memory bus, handles the transfer of all data and instructions between functional areas of the computer. The bidirectional data bus can only transmit in one direction at a time.
The data bus is used to transfer instructions from memory to the CPU for execution. It carries data operands to and from the CPU and memory as required by instruction translation. The information on the data bus is either written into The data bus is not limited to transferring data; it is also used to transfer program instructions.
Discuss six roles of operating systems Without an operating system, a computer is little more than a bundle of plastic, metal, and a few bits of expensive silicon. Whereas most software runs on a computer, the operating system is the software that runs the computer. Below are major roles of operating systems I. Provides a user interface: Facilitates easy communication between user and computer with interpretation of commands and instructions. CLI requires the user to interact with operating system in the form of text keyed in from the keyboard.
In this, the user has to learn and remember the different commands required for copying, deleting, opening a file or folder etc. File management: the operating system manages reading and writing in the file system and the user and application file access authorizations. It keeps track of where all the files are on the computer.
The file management system allows the user to perform such tasks as creating files and directories, renaming files, coping and moving files, and deleting files. Also keeps track of where files are located on the hard drive through the type of file system.
Management of the random access memory: the operating system is responsible for managing the memory space allocated to each application and, where relevant, to each user.
Also responsible for managing all system memory which is currently in use by programs. This ensures that a program does not interfere with memory already in use by another program. Since programs time share, each program must have independent access to memory. The activities of memory management handled by OS are— 1 allocate memory, 2 free memory, 3 re-allocate memory to a program when a used block is freed, and 4 keep track of memory usage.
Protection and Security— OS protects the resources of system. User authentication, file attributes like read, write, encryption, and back-up of data are used by OS to provide basic protection. The access of programs, processes, and users, to the resources defined by the computer are controlled by the protection mechanism. Protection ensures that the resources of the computer are used in a consistent way.
Security mechanism prevents unauthorized access to the computer. Security concerns include—security of software, security of data stored in the computer, and security of physical resources of the computer. In a personal computer, security can be ensured using— 1 user accounts— individual accounts for each user, 2 user authentication—using password protection 3 access rights—define rights for access of different kind of information for different people, 4 data encryption—store data in computer in encrypted form, and 5 data backup—storing data on a peripheral device other than the hard disk.
In a networked environment, only trusted computers should be able to share data. Some of the common security threats occur due to hacking, viruses etc. Device Management— The device management tasks handled by OS are— 1 open, close and write device drivers, and 2 communicate, control and monitor the device driver.
Several peripheral devices like mouse, hard disk, printer, plotter etc. The peripheral devices have varying characteristics like character or block device, sequential or random access device, and dedicated or shared device.
OS manages and controls the devices attached to the computer. OS provides appropriate functionality to the application programs for controlling different aspects of the devices. OS handles the devices by combining both hardware and software techniques.
The device driver software comes along with each device. A device communicates with the computer hardware via a port for example, a serial port or a parallel port. Bus is a common set of wires used by one or more devices. A device controller operates a port, bus, and a device.
Device controller is just like a bridge between the device and the operating system. Device driver is the software with which the device controller communicates with the operating system.
A process is a program in a state of execution. It is a unit of work for the operating system. A process can be created, executed, and stopped. In contrast, a program is always static and does not have any state.
A program may have two or more processes running. A process and a program are, thus, two different entities.
The process management function of an operating system handles allocation of resources to the processes in an efficient manner. The allocation of resources required by a process is made during process creation and process execution. A process changes its state as it is executed.
A standard process describes the steps needed for processing to take place. To browse Academia. Log in with Facebook Log in with Google. Remember me on this computer. Enter the email address you signed up with and we'll email you a reset link.
Need an account? Click here to sign up. Examples of Analog Computer These types of computers are not for measuring physical quantities such as temperature, electric current, and voltages. They are high-speed programmable machines or computers which can play out numerous mathematical calculations and can store data or information.
Just, for example, there are some machines that can calculate the heartbeats and temperature of the human body and convert or change them into numbers.
Wow, amazing weblog layout! How long have you been running a blog for? The mainframe is a highly efficient computer capable of simultaneously solving complex calculations and continuously for a long time. These computers have several microprocessors that have the ability to function the data at too high performance and speed.
The mainframe is ahead of our conventional modern Personal computers in almost every metric. Somehow mainframes can be more powerful than supercomputers because the mainframe supports many processes simultaneously. On the other hand, supercomputers can run a single program but faster than a mainframe. In the past, Mainframes requires entire rooms or even floors of whole buildings for set up. In today, IBM company is leading the production of mainframe computers.
Mainframe reliability is increased with development in the past 60 years. These computers can fix most of the hardware and software bugs. Mainframe computers are mainly used by departmental and commercial organizations like Banks, Companies, Scientific research centers, and governmental departments like railways.
These computers can work for 24 hours. Hundreds of users can work on these computations simultaneously. Using the mainframe completes the tasks, Such as keeping details of payments, research centres, advertising, sending bills and notices, paying employees, ticket booking, maintaining details of purchases by users, keeping detailed tax details, etc. Minicomputer is a digital and multi-user computer system with the connection of more than one CPU.
Thus, many people can work on these computers simultaneously instead of a single person. Also, it can process with other accessories like a printer, plotter, etc. Minicomputers are the medium type of computers that have more functionality power and are expensive than microcomputers.
On the other hand, the size, storage, and speed of minicomputers are large but less than the mainframe and supercomputers. Minicomputers are made for performing multiple computing tasks at a single point of time, instead of assigning many microcomputers for a single task, which will be time-consuming and expensive.
In general, a minicomputer is a multi-threaded system several processes at a time capable of supporting from one to up to users simultaneously: these computers are currently used to store large databases, multi-user applications, and the automation industry.
The minicomputers are used as real-time applications in Industries, bookings, and Research Centres. As well as in the field of Higher Education and Engineering.
Today we are using many computers at home is also the most common microcomputer. With this invention of the microprocessors in the year , it became possible to use computers for people personally at a low cost and reasonable price known as Digital Personal Computer. The design of microcomputers is minimal in size and storage capacity.
These computers consist of many parts like Input and Output devices, Software, operating systems, networks, and Servers all these need to connect to form a complete Personal Digital Computer. There is not only a PC or laptop are examples of microcomputers. Other examples of the microcomputer are smartphone, Tablet, PDA, server, palmtop, and workstation.
The primary purpose of microcomputers is to keep and process the everyday tasks and needs of the people. Only one person can work on a single PC at a time, but its operating system is multitasking. The PC can be connected to the Internet to take benefits and enhance the user experience. The development of multimedia, small equipment, optimized energy consumption, and the LAN made the microcomputers increase in demand for every field.
0コメント