Ch 2- Hardware and software

• Main principles:

  • Computer hardware must be carefully selected to meet the needs of the organisation and its supporting information system
  • Systems and application software are critical in helping individuals and organisations meet their goals. Organisations should not develop an application software if it does not provide competitive advantage Organisations should choose a functional programming language
  • Each program processes its input through one or more central processing unit and primary storage

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• Central Processing Unit (CPU): electronic circuit that executes instructions comprising a computer program
  1- Arithmetic/logic unit (ALU): performs maths calculations + makes logical comparisons
  2- Registers: high speed storage areas that temporarily hold small units of program instructions and data immediately before/during/after execution by the CPU
  3- Control unit: accesses program instructions, decodes them, and coordinates the flow of data in and out of ALU, registers, primary+secondary storage, and various output devices

• Primary storage / Main memory: provide the CPU with a working storage area for program instructions and data
  → rapidly provides data + instructions
  → contains thousands of circuits imprinted on a silicon chip. Each circuit is whether conducting electrical (on) or not (off), known as Binary digits, or bits

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• Secondary storage: or permanent storage, allows organisations to store large amounts of data + instructions

  • advantages compared to main memory:Non-volatile, greater capacity, greater economy

• Secondary storage devices examples:

  • magnetic tape, magnetic disk, virtual tape, optical discs, digital versatile disc, holographic discs, memory cards-RAID (redundant array of independent/inexpensive disks)

• Data input: input requires requires transferring human readable data into the computer system

  • machine readable data are barcodes for example

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• Two stage process:

  • Data entry: human readable data → machine readable data
  • Data input: machine readable data → into the system
  • Input devices: -keyboard and mouse, digital cameras, recognition
  • Technology: speech
  • optical data readers (OMR): reads handwriting, magnetic ink character recognition (MICR), magnetic stripe card, automated teller machines (ATM), point of sale devices

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• Output devices: display monitors, liquid crystal display (LCD), OLED -printers, digital audio player, GPS, 3D printers

• Computer systems: desktop PC, workstation (more powerful than a PC)

• Server: used by many users to perform a specific task

  • large memory, strong capacities, fast + efficient communications abilities

• Web server handles internet traffic → Internet caching server stores websites

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• Enterprise server: stores and provides access to programs that meet the needs of the organisation

• File server: stores and coordinates program and data files

• Email server: sends and receives emails

• Mainframe computers: large powerful computer shared by dozens of concurrent users connected to the machine over a network

• Supercomputers: most powerful with fastest processing and highest performance

  • designed for apps that requires extensive computational capabilities

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• %%Software:%% Software consists of computer programs that control the workings of a computer hardware

  • A computer program is a sequence of instructions for the computer program
  1. Systems software
  2. Application software

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1. Systems software (Operating system (OS)): set of programs that control the computer hardware and acts as an interface with applications. A software should provide a user interface.

   • Example: - graphical user interface (GUI)

   • command based interface: where commands must be typed at a prompt

   • memory management, processing tasks, networking capabilities, file management, access to system resource and security, Enterprise operating systems are like a computer, OS, which provides the services that business functions and operations run on.

   • Z/OS, MPE/iX, HP-UX and linux → an OS from IBM which means makes it easier and less expensive for users to run large mainframe computers

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2. Application software gives people, workgroups, and the entire enterprise the ability to solve problems and perform specific tasks

   • Programming languages: provide instructions to the computer system so that it can perform a processing activity. Translate what a user wants to accomplish into a code that the computer can understand + execute
     • Graphical user interface (GUI): user interface that uses icons + menus displayed on screen to send commands to the computer systems

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