Understanding Computer Systems

Computer System

• A computer is a machine using electronic components perform calculations, repetitive and complex procedures, process text, and manipulate data and signals

What a computer can and cannot do

• A computer can process information fast
• It can give accurate results
• A computer can store information
• It can restore previous work
• A computer can multitask
• A computer cannot do what you didn't command
• It cannot generate information on its own
• A computer cannot distinguish wrong/correct data
• It cannot correct wrong instructions

Classification of Computers

• Supercomputers are designed for complex scientific calculations
• They are used in weather forecasting and climate change, space exploration, aviation engineering, etc.
• Supercomputers are expensive and bulky
• Mainframe computers support organizational information systems, such as hospital information systems
• They have a large storage capacity and are expensive
• Minicomputers are a small version of mainframe computers
• They have less complex processing and are relatively expensive
• Personal computers are designed for a single user
• They can connect to other users and offer personalized capabilities
• Laptops/Notebooks are portable versions of a personal computer
• They are more expensive than personal computers
• Tablet computers are smaller than notebook computers
• They are more expensive than laptops
• Tablet computers might have transmission issues in dead zones
• Hybrid/Smartphones combine text messaging and other internet services
• They typically have small keys and screens
• Embedded computers are an integral part of devices and serve special purposes
• They have limited functionality
• The computer is embedded into the function of the machine

Impact of Computers on Society

• Positive impacts include increased productivity
• Information is shared easily
• Communication is now elaborate
• Data is stored and accessed easily
• Consistent output is being produced
• Negative impacts include increased unemployment
• Data piracy
• Huge data loss

Computer Hardware

• Computer hardware includes all the physical components of the machine
• It is composed of different parts that enable the user to communicate with it and with other computers to produce work
• Computer hardware utilizes electronic components and instructions to perform calculations and repetitive and complex procedures, process text and manipulate data and signals
• Computer hardware characteristics include being automatic and electronic
• They are suitable for general purposes needing speed, reliability, and storage capacity

Basic Components of Computer Hardware

• Central Processing Unit (CPU)
• Input and Output devices
• Storage media

Central Processing Unit (CPU)

• The CPU is considered the brain of the computer
• It consists of an arithmetic and logic unit, a control unit, and memory
• The CPU's components are the Arithmetic and Logic Unit
• Control Unit (fetch, decode, execute and store)
• Memory (RAM and ROM)
• Read Only Memory (ROM) is permanent storage, can only be read, and cannot be erased/altered
• ROM includes software and programs that cannot be erased when the computer is turned off
• Random Access Memory (RAM) is working memory used for working storage
• RAM can be changed, accessed, used, and written on repeatedly
• A motherboard is a printed circuit board and the foundation of a computer and is the biggest board in a computer chassis
• It allocates power and allows communication between the CPU, RAM, and all other computer hardware components
• A CPU microchip, also known as a microprocessor, is a complete computation engine, fabricated on a single chip
• It is the heart of any normal computer, whether it is a desktop machine, server or a laptop
• CPU performance is measured in MIPS or “millions instruction per second",

Input and Output

• Input and output are used to receive commands and data from the outside and for reporting its work
• Wired to a controller that is plugged into the slots or circuit boards
• Input devices allow the computer to receive information from the outside world
• Input devices include mice, keyboards and scanners
• Output devices are used to report the results to the external world

Storage Media

• Storage media includes main memory
• it also includes external devices on which programs and data are stored
• Hard drives are a peripheral that has a high speed and high density
• Diskettes are a round magnetic disk encased in a flexible case
• CD ROM’s are rigid disk that holds a much higher density of information than a diskette and has a much higher speed
• CD RW a newer type of CD that could be written on by the user
• USB DISK/FLASHDRIVE is a small, removable hard drive that is inserted into the USB port of the computer
• Magnetic tape drives run a magnetic tape the same way with any music tape player
• ZIP and JAZ DRIVE are similar to a floppy disk but are of higher capacity

Common Hardware Peripherals

• Keyboards are a common input device, similar to a typewriter keyboard, and are connected to the box with a cord
• Types of keys found in keyboard are as follows a. Typewriter Keys b. Function Keys c. Numerical Keys d. Cursor Keys e. Toggle Keys f. Special Operation Keys
• A Monitor is a display screen component that allows the user to see images, programs, and commands.
• Similar to a television screen however the resolution or clarity is related to the number of dots, pixels on the screen
• A Mouse and trackball are a controlled mechanical device that electronically instructs the cursor to move across the video display screen
• A Touchpad and mouse button are a flat, rectangular depression on the keyboard that senses pressure and movement of the user's finger
• A Light pen/touch screen are a photosensitive device that respond to light images when placed against a monitor screen
• Optical character recognition allows data to be read directly from a form or document
• An electronic optical scanning device or a barcode reader that interpret marks, codes, numbers, letters, or characters;
• Imaging primarily transform images from various types of graphics into digital form which the computer can accept, represent on the screen and process
• Many types of graphics and images on paper such an xray
• Printers converts information produced by the computer system into printed form a. Laser printers b. Inkjet printers c. Bubble Jet printers
• Modems are a communication device used to connect a terminal with a mainframe or another computer
• Computers are now pervasive throughout the healthcare industry
• Their applications are expected to continue to expand and thereby improve the quality healthcare while at the same time reducing some cost

Computer Hardware Advancement in Healthcare

• There were Advances in 1900's and 2000's
• The first work was administrative function
• Non invasive visualization in radiology
• Computer enhanced surgical instruments
• Telemedicine is now being used

Computer Software

• Software is a kind of program that enables the user to perform some specific task or used to operate a computer
• It directs all the peripheral devices on computer system – what to do and how to perform work

Types of Software

• System Software
• Utility Software
• Application Software
• System software controls the operation of the machine and how it works
• It include peripheral equipment and supports utility and application program
• An Operaating System is an example of system software (MAC OS, Windows)
• Utility software supports efficiency, productivity, and security of the systems and application systems
• It includes algorithms, file manager tool, compression tool, Disk Management tool, Disk clean up tool, Disk defragmenter tool, and security program such as antivirus
• Application software includes various programs people used to do work, process data, play games, communicate others or watch multimedia programs on computer
• Application programs are written in a particular programming language

Important Features of Application Software

• Perform more specialized tasks like word processing, spreadsheets, email, photo editing, etc.
• It needs more storage space as it is bugger in size
• Easy to design and more interactive the user
• Generally written in high-level language

Types of Application Software Based on Usage

a. Word processing software – it makes use a computer for creating, modifying, viewing, storing retrieving, and printing documents. b. Spreadsheet software – is a numeric data analysis tool that allows you to create a computerized ledger c. Database software – is a collection of related data that is stored and retrieved according to users demand d. Graphics software – it allows computer systems for creating, editing, drawings, graphs, etc. e. Education software – allows a computer to be used as a learning and teaching tool f. Entertainment software- this type of app allows a computer to be used as an entertainment tool

• System software is capable of running independently while Application software can't run independently
• The system software starts running when the system is powered on and runs until the system is powered off while Application software starts when the user begins, and it ends when the user stops it
• System software is independent of the application software while an application software needs system software to run

Computer System Elements

• Input – any external factor taken in the system
• Process – activity of the system
• Output - product or waste of the system
• Control – any component of the process that corrects/prevents error
• Feedback – output from a process that can serve as input
• An information system is an integrated set of components for collecting, storing, and processing data and for providing information, knowledge, and digital products.
• Management Information system
• Bibliographic Retrieval Systems
• Transaction Systems
• Stand-Alone Systems
• Hospital Information System
• Administrative Module
• Clinical Module
• Administrative Module is responsible for managing information relevant to the management of the hospital
• It includes finances, records of employee, etc
• Clinical Module contains all the information relevant to your patients
• An example is connecting the clinical module to the laboratory department to easily access laboratory results of the patient.