Information Systems Hardware: Microcomputers

• Chapter focuses on information systems hardware, including categories and components of computer systems.

Categories of Computer Systems

• Microcomputers are relatively inexpensive computers using a microprocessor as its CPU.
• Microcomputers are used by a single user at home or in the office and feature a system unit, as well as input, storage, and output devices.
• Microcomputers are cheaper and more practical than supercomputers, mainframe computers, and minicomputers.
• Microcomputers can also connect to the Internet.
• Desktop computers- personal computing devices designed to fit on a typical office desk
• Two types of microcomputers computers:
  • Desktop computers
  • Mobile computers
• Mobile computers are handheld computers that are portable, light, and can fit in one's hand.
• Mobile computers include Notebooks/laptops, which are thin, lightweight computers with a keyboard attached to a monitor; Tablet PCs which enable touch screen interactions using fingers or a stylus; and Smartphones.
• Besides phone calls, smartphones manage personal information, photo-taking, data sharing, and internet access applications.
• Portable media players, also known as MP3 players, like iPods, are a type of mobile computer.
• Other mobile devices are handheld game consoles, such as the Game Boy, PlayStation Portable (PSP), and PlayStation Vita which are tiny computers for gaming on the go.
• Minicomputers are small, general-purpose computers that use one or more processors to serve multiple users and process significant amounts of data.
• Minicomputers can support approximately 200 simultaneous users.
• Minicomputers are faster than microcomputers but slower than mainframes and supercomputers.
• A server can be a minicomputer.
• Minicomputers are used to store centralized data and files within an organization.
• Mainframe computers are large, powerful computers used for centralized storage, processing, and management of very large data amounts.
• Large corporations such as banks, needing mission-critical applications with high data processing volumes, own Mainframe computers.
• Mainframes are capable of handling and storing huge amounts of data and information, allowing access to thousands of network users.
• Supercomputers are an extremely expensive and fast type of computer.
• Supercomputers are used to perform complex calculations and simulations.
• The Frontier is currently the world's fastest supercomputer
• The Frontier cost $600 million.
• Supercomputers are vital for advanced scientific work because they can perform rapid calculations for applications such as weather forecasts and missile development.
• Supercomputers cover a large space, like an entire floor.

Components of Computer Systems

• Computer components include the system unit, input devices, output devices, and storage media.
• The system unit houses the primary devices that perform operations and produce results for complex calculations.
• The system unit includes the motherboard, processor, and primary memory.
• The motherboard is a single integrated circuit board that holds and enables communication between all electronic components of a computer.
• The motherboard holds and connects the processors, memory, cards, and cooling devices.
• The Processor, or CPU (Central Processing Unit) , is the "brains" of the computer.
• The CPU is where most calculations and instruction executions take place.
• The CPU is the most important element of a computer system.
• Two typical components of a CPU include the arithmetic logic unit (ALU) and the control unit (CU).
• The arithmetic logic unit (ALU) performs arithmetic and logical operations, such as add, subtract, multiplication, division, true, false, >, <.
• The control unit (CU) extracts instructions from memory, decodes and executes them, and calls on the ALU when needed.
• Primary memory, a section of computer memory the CPU can directly access, must be present for the computer system to work.
• The two major types of primary memory are volatile and non-volatile memory.
• Volatile memory loses its contents when the computer loses power; RAM (Random Access Memory) is volatile.
• RAM is used to store computer programs and data used by the CPU in real time.
• Non-volatile memory retains its contents after the power is switched off; ROM (Read-Only Memory) is non-volatile.
• ROM, also known as firmware, stores permanent data, instructions, and information, and stores instructions for the computer to start up when turned on.
• Key differences between RAM and ROM:
• RAM is for random access memory and ROM is for read-only memory
• RAM is volatile and ROM is Non-volatile.
• RAM data can be read, erased or modified, and ROM data can only be read.
• RAM speed is high, and ROM speed is low compared to RAM.
• Input devices are hardware devices that send data to a computer.
• Input devices include keyboards, pointing devices, touch screens, pen inputs, game controllers, digital cameras, scanners, and webcams.
• Keyboards are the most popular input device and consist of keys used to type data; keys are usually arranged in QWERTY layout, like a typewriter.
• input devices can consist of: mouse, trackball, touchpad, pointing stick,
• Mouse, trackball, touchpad, or pointing stick are used to control the mouse and actions of the pointer on the screen.
• Touch screens capture input through touch or movement of fingers; they are used in tablet PCs, monitors, smartphones, and information kiosks
• Other input devices:
  • Digital cameras, which allow users to take digital pictures and video clips.
  • Scanners, which convert printed materials such as text and images into digital forms.
  • Optical Character Recognition(OCR) readers, which converts scanned documents, PDFs, and images into machine-readable text.
• Output devices are hardware devices that accept data from a computer and either print, project, or reproduce that data.
• Monitors, printers, plotters, speakers, and data projectors are all output devices.
• Output is classified into softcopy and hardcopy.
• Softcopy is a temporary display of output data.
• Hardcopy is a permanent data display.
• Examples of output devices:
  • Monitors display output in pictorial or textual form and produce softcopy.
  • CRT (Cathode-Ray tube), LED (Light-Emitting Diode), LCD (Liquid Crystal Display) are types of monitors, with many more options available.
  • Printers transfer text and graphic output from a computer to paper (hardcopy).

Types of Printers

• Impact printers: Output is printed on papers because the print head strikes the inked ribbon that makes contact with the surface of the paper, producing sound (e.g., dot matrix printers, line printers, daisy wheel printers).
• Non-impact printers: Output is printed on papers without direct contact between the print heads and physical medium, therefore produces less sound (e.g., laser printer, ink-jet printer, thermal printer).
• Dot matrix printers use hammers and a ribbon to form images from dots.
• Line printers make use of a continuous paper feed and print one line of text at a time.
• Ink-jet printers spray tiny drops of ink onto the paper and produce better quality prints than impact printers.
• Laser printers use laser beams and toners (powdered ink) to leave marks on the paper through pressure and heat; they operate at high speed and produce high-quality prints.
• Thermal printers use heat to generate images and texts on paper with a quality lower than laser printers.

Storage Media (Secondary Storage)

• Storage media- stores data and information for future usage.

• Storage media is also be referred to as secondary storage.

• Storage media includes hard disks, memory cards, cloud storage, and optical disks.

• Storage media is measured by capacity and calculated in bytes, from KB (kilobytes) to MB (Megabytes) and GB (Gigabytes).

• One char is equal to 8 bits

• 1 byte is equal to 8 bits

• 1 KB is equal to 1024 bytes

• 1 MB is equal to 1024 KB

• 1 GB is equal to 1024 MB

• 1 TB is equal to 1024 GB

• The largest storage media is TB (Terabytes).

• Data or information is transferred from memory to the storage media using write heads and retrieved from storage media to memory using read heads.

• A hard disk is a magnetic disk used to store data. It has a big capacity and fast speed. It consists of several circular platters enclosed in a vacuum casing

• Flash-memory storage is a non-volatile storage medium that stores data without a power supply. Data can be stored, erased, or rewritten, and it is mobile, smaller, and more durable than a hard disk. Users can carry flash memory-storage in their bags, pockets, or pencil cases. Examples include USB drives and Memory cards.

• Flash-memory storage has faster transfer and access times, generates less heat and consumes less power compared to hard disks.

• Cloud Storage provides web-based storage services for free or for a small token fee, used by those who are always on the move.

• Examples of cloud storage include email applications, online file storage, and social media networks.

• Cloud storage enables users to access storage from any computer with Internet access, store large files, share files with friends, and serve as a backup for existing data.

• An optical disc is a storage device shaped like a round, flat plate that uses a low-powered laser beam to store and read data, used primarily to store music, movies, software, and photos

• Optical disc types: CD-ROM (Compact disk read-only memory), CD-RW (Compact disk rewritable), DVD (Digital versatile disk), and Blu-ray.

  • Blu-ray is a more expensive type of DVD offering higher capacity and quality.