Nursing informatics ii

Iloilo Doctors CollegeCollege of NursingComputer Hardware PeripheralsKEYBOARD Is the most common input deviceSections of keys:Typewriter keysFunction keysNumeric keypadCursor keysToggle keysSpecial operation keys

COMMON HARDWARE PERIPHERALS

Typewriter key section is the largest and contains keys that follow the standard QWERTY arrangement of keys of a standard typewriter.

Function keys (F1-F12) are software specific; that is they are programmable, since their function is dependent on the software program being process.Eg. F10 is used to retrieve a file in one word processing package and to save in another.Shift, Ctrl, and Alt keys expand the function keys by using in combination with them carry out other commands. Numeric keypad The second set of numeric keys that are placed differently on the keyboards than the alphabet keys. It enables the user to enter numeric data more efficiently.Num Lock keyCursor keys Major toggle keys:Num lockCaps lockScroll lockInsert/Typeover Special operation keys:Home and end keys bring the cursor to the beginning or the end of the line. Print screen print the screen display or saves it to the clipboard as a snapshot. ESC (escape) interrupts or cancels a function. Tab key moves the cursor to predetermined set tabs.Del key - delete text.Space bar inserts blank space in a line.Enter key performs a variety of function depending on the context of the program. It sends information to the computer, such as during sign-on procedures, in word processing it creates a new paragraph, and it can be used to create a blank section in a document.

MonitorIt is a display screen component of a terminal that allows the user to see images, programs, commands the user send to the computer, and results of the computers work (output).The resolution or clarity of the monitor screens is related to the number of dots, pixels, on the screen. As the pixel count rises, the sharpness and clarity of images and colours on the screen improve.

Mouse The type of input device that electronically instructs the cursor to move across the video display screen. The mouse has at least two button and sometimes a roller at the top. The left button is used primarily to:Select the iconActivate the processImplement the function to be performed The right button is a special function button, and its function is dependent on the program. It requires the certain amount of space on a desk, often runs off the pad and must be repositioned to work.Trackball has the ball on the top, and movement of the cursor is controlled by the fingers rolling the ball in place.

Floppy Disk/Diskettes and CD-ROMs another form of secondary storage or auxiliary memory which serves as both input and output media.

Touch Pad and Mouse Button Touch pad was developed by the makers of laptop computers for use in place of mouse. It is flat, rectangular depression on the keyboard that senses pressure and movement of the users fingers.

Touch ScreensUses an electronic visual display that the user can control through simple or multi-touch gestures by touching the screen with one or more fingers.

Touch screens involve the use of a special filter on a monitor screen that allows the screen to sense the pressure of the users finger on a particular position of the screen. That pressure can signal the computer to initiate the action (similar to a mouse click) or can function to let the user select a particular item on the screen, such as on a menu.

Light penA light pen is a photosensitive device that responds to light images when placed against a monitor screen. When the pen in contact with the display screen it highlights the items and sends the data to the computer.

Optical Character RecognitionIs a specialized computer input medium that allows data to be read directly from a form or document. An electronic optical scanning device, a wand reader, or a bar code reader reads special marks, numbers, letters or characters.

Magnetic Ink Character Recognition (MICR)A medium for reading characters by computer wherein characters are made of magnetized particles printed on paper.

Voice / Speech SynthesizerInputs data into the computer by speaking into a connected microphone.

ImagingTransforms images from various types of graphics into digital form which the computer can accept, represent on screen and process.Eg. CAT scan, MRI

Digital Versatile Disk (DVD)Holds more information than a CD-ROM and contains multimedia features.PrintersConverts information produced by the computer system into printed form (hard copy-paper, microfilm-microfiche, photograph and graphic).

Modem (Modulating and Demodulating device)A communication device used to connect a terminal with a mainframe or another computer.It translates digital data into waves for transmission over communication lines to the computer system and converts the waves back to their original digital form for input into the computer. Eg. faxNetworkA set of cooperative interconnected computers for the purpose of information interchange. This includes:a. Local Area Network (LAN)Supports interconnected computer needs of a single company or agency.b. Wide Area Network (WAN)Supports geographically dispersed facilities.Eg. national coverage c. Internet

Basics of Computer Network HardwareComponents:1. Network adapter/ network interface cardIt is a computer circuit board or card that is installed in a computer so that it can be connected into a network.Network Hardware- provides interconnection between computers

2. Communication medium (cabling)It is a means by which actual transfer of data from one site to another takes place.Eg. Twisted pair cable, coaxial cable, fiber-optics, telephone lines, satellites, and compressed video.

Essentials of a Communication Medium:Distance requirementsShort distance-compressed video and coaxial cablesLong distance- Fiber-optics, telephone lines and satellite transmission

Amount of data transferLarge amount of data (eg. video)- best handled with coaxial cables and compressed video and satellite communicationsSmall amount of data or serial (non-video)- can be handled by twisted pair copper wire and optical fiber

How the transfer is neededConstant use of limited users- CoaxialHigh usage of public networks (internet)-telephone wires

AvailabilityThis depends on cost, transmission speed, number of users, weather conditions, etc.Also called as the Integrated Services Digital Network (ISDN)Lines used to carry sets of communication standards for optical fibers that carry voice, digital and video signals across phone lines.

Types of ISDN Connections with different bandwidth (controls how fast the signals can be transmitted across the phone lines)1. DS0- Digital bandwidth- zeroth level- 64 kilobytes/sec

Telephone Line Communications2. T-lines- used to handle high-speed transmissions needed for network communications

Cable ModemA cable network can achieve speed faster than the maximum speed of a telephone modem connectionAn external cable modem box is added to the computer configuration which contains:a. Tuner- receives signals and passes these to the demodulatorb. Demodulator- takes radio and analog information and converts it to digital data, performs data correction functions, checks for problem transmissions and passes the signal to the modulator.

c. Modulator- works with upstream traffic to convert the digital signals into radio frequency signalsd. MAC (Multiple Access)- acts as an interface between the various parts of the network protocolse. CPUf. Network hardware

ServerIt is a computer program that provides services to other computer programs in the same computer or in other computers on a network.Architecturerefers to the overall physical structure, peripherals, interconnections within the computer and its system software, especially the operating system5 Components / Computer subsystems:Input/OutputStorage CommunicationControlProcessingNetwork ArchitectureRefers to how communication among various computers in the network is accomplished.2 Types:1. BroadcastCommunication is done by transmitting the same information to all computers in the network that are expected to respond to it.Typically used in LANs2. Point-to-pointThe computer for which information is intended is identified first and the communication is only to that particular computer.Typically used in dial-up networkingTopologyThis defines how the network computer in a LAN are interconnected within a physical area and describes their physical interconnection.Examples:Bus- structure is decentralized

* If one of the computer fails, other computers can still access the informationStar- central structure where all computers are connected into a central computer or the server

* If the central computer fails, information cannot be sent or received by any of the computers connecter to this server.

Token Ring having the server pass a marker or a token to the computer that is next in line to communicate.No computer can send or receive data unless it is the target of the token.Collisions between 2 workstations that wish to transmit information at the same time are avoided.