MICROCOMPUTER HARDWARE & SOFTWARE INTERNET” There are four types of computers: supercomputers, mainframe computers, minicomputers, and microcomputers. Supercomputers are the most powerful type of computer. These machines are special high-capacity computers used by very large organizations.
For example, NASA uses supercomputers to track and control space Mainframe computers occupy specially wired air-conditioned rooms. Although not nearly as powerful as supercomputers, mainframe computers are capable of great processing speeds and data storage.
For example, insurance companies use mainframes to process information about millions of policyholders. Minicomputers, also known as midrange computers, are refrigerator-sized machines. Medium-sized companies or departments of large companies typically use them for specific purposes.
For example, production departments use minicomputers to monitor certain manufacturing processes and assembly line operations. Microcomputers are the least powerful, yet the most widely used and fastest-growing, type of computer. There are four types of microcomputers: desktop, notebook, tablet PC, and handheld computers.
Desktop computers are small enough to fit on top of or alongside a desk yet are too big to carry around. Notebook computers, also known as laptop computers, are portable, weigh between 4 and 10 pounds, and fit into most briefcases. A tablet PC is a type of notebook computer that accepts your handwriting.
This input is digitized and converted to standard text that can be further processed by programs such as a word
processor. Handheld computers are the smallest and are designed to fit into the palm of one hand. Also known as palm computers, these systems typically combine pen input, writing recognition, personal organizational tools, and communications capabilities in a very small package. Personal digital assistants (PDA) are the most widely used handheld computer.
Hardware for a microcomputer system consists of a variety of different devices. for a typical desktop system. This physical equipment falls into four basic categories: the system unit, input/output, secondary storage, and communication. Because we discuss hardware in detail later in this book, we will present just a quick overview of the four basic categories of microcomputer hardware:
The system unit, input/output, secondary storage, and communication. System unit: The system unit, also known as the system cabinet or chassis, is a container that houses most of the electronic components that make up a computer system. Two important components of the system unit are the microprocessor and memory.
The microprocessor controls and manipulates data to produce information. Many times the microprocessor is contained within a protective cartridge. Memory, also known as primary storage or random access memory (RAM), holds data and program instructions for processing the data.
It also holds the processed information before it is output. Memory is sometimes referred to as temporary storage because its contents will typically be lost if the electrical power to the computer is disrupted. Input/output: Input devices translate data and programs that humans can understand into a form that the computer can process.
The most common input devices are the keyboard and the mouse. Output devices translate the processed information from the computer into a form that humans can understand. The most common output devices are monitors or video display screens and printers.
Secondary storage: Unlike memory, secondary storage devices hold data and programs even after electrical power to the computer system has been turned off. The most important kinds of secondary media are floppy, hard, and optical disks. Floppy disks are widely used to store and transport data from one computer to another.
They are called floppy because data is stored on a very thin flexible, or floppy, plastic disk. Hard disks are typically used to store programs and very large data files. Using a rigid metallic platter, hard disks have a much greater capacity and are able to access information much faster than floppy disks. Optical disks use laser technology and have the greatest capacity.