INFO1 – Practical problem solving in the digital world
These transfer information into a computers CPU.
Putting information into a computer Keyboard MouseDigital CameraMicrophone Scanner Joystick / Control Pad Touch ScreenTouchpad
The most common input device is the QWERTY keyboard. They contain letters, numbers, special keys e.g. ESC, ALT, CTRL, SHIFT and function keys e.g. F1 It allows you to input letters and numbers. You can also carry out commands like delete, home, end, page up and page down. Ergonomic keyboards are designed to reduce RSI (repetitive strain injury).
Is still the most common pointing device. It uses a pointer to select options by clicking. Can be connected by cable or wirelessly. What other types of pointing device do you know of?
Mechanical mouse – uses a rolling ball Optical mouse – use a light sensor Tracker ball – the ball is rolled with the fingers Trackpad – uses the finger on a touchpad Trackpoint – a small button that acts like a joystick.
Keyboards divided into areas labelled to suit the purpose. They use special software to interpret they keys pressed. Used in checkout tills or restaurants or people with disabilities. They have names of items or colours etc on keys.
They sense an area of the screen has been touched using embedded wires or infra-red light beams. Often used in public areas as they are easy to use and they combine both input and output. Usually have a selection of items from a menu and a virtual keyboard for text input.
Used mainly for drawing using a stylus on a flat plate. The stylus is like a pencil, so feels more natural to draw with compared to a mouse. Good for languages like Chinese that use symbols rather than text.
Touch sensitive computer displays used in schools. You can draw and operate the computer using either a stylus or finger depending on the type of board. Again combines input and output.
Involves speaking into a microphone. The sounds are converted into text words using speech recognition software. Different voices and accents and background noise can make them unreliable. Also difficulties occur with similar sounding words like ‘there’ and ‘their’. Better when words are spoken distinctly, but this can be slow.
Some devices read data from media that is stored on them. Sometimes stored magnetically, or on paper.
Magnetic strip cards are swiped through a card reader or fed into a card slot. They are easy to read but can’t hold much data. A smart card, such as chip and pin, has a computer chip built in. They can hold far more data than a magnetic strip and can have data written to it. They are secure as they can be encrypted and are operated with a PIN.
Uses radio waves to transmit signals as an ID for objects. Tags are attached to items and they transmit radio signals, which are picked up by a reader, which send the data to a computer. Most commonly used for transport and logistics. The goods can be tracked on their journey.
Scanners are used to change paper based information into a digital format that can be used by a computer. A beam of light scans the page and senses the colour variations. The quality of the image depends on the resolution (dpi) the scanner is set to. Higher resolution – higher quality image
Flat bed scanner Bar code scanner Hand held scanner Sheet-feed scanner Drum scanner
Used mainly for exam paper marking and lottery tickets. OMR use a light beam to sense pencil or other marks on the page. Software works out the value of the mark depending on its position. The forms need to be specially printed and software configured so can be expensive to set up. But fast and reliable.
In OCR paper documents are scanned, each part of the image is compared to a dictionary of known letter shapes. Letters are converted into computer characters. Good quality software can pick up layout and formatting in a document. Organisations use OCR to input forms filled in by clients or employees. Can be used on things like passport applications, but forms need to be completed accurately. Its much quicker than manually entering data.
A bar code is a pattern of black and white lines which represents a number. Often used in electronic point of sale (EPOS) systems. The number acts as a primary key for the product in a database. They have built in error checking and reduce mistakes of having to type in the product number.
Used exclusively by banks to process things like cheques. Important account numbers are printed with an ink containing magnetic particles. A magnetic reader translates them into numbers that can be stored by the computer system. Is now used less than previously as many payments are now made electronically.
When a sound is fed into a microphone it creates an analogue signal made up of changing voltages. If it’s to be used by a computer it needs to be converted to a digital signal. This is called sampling. The voltage is measured and a digital equivalent of the waveform is made. Higher sample rate (more measurements per second) creates a better quality sound.
Music can be recorded on a computer using instruments linked via Musical Instrument Digital Interface (MIDI). Rhythms and sounds can be transferred, edited and mixed on the computer.
A video picture is made up of many still pictures played rapidly in sequence. Digital video cameras record images to hard disk, DV tape or DVD.
Small video cameras often used for video conferencing. Not usually very high quality, keeping file size down, the video images are sent to the computer in a continuous stream. Used frequently through instant messaging and internet phone services.
Records electronic images or videos usually on to a flash or XD memory card. These can be downloaded onto a computer and printed, stored or edited. Can be connected through cables or wirelessly through Bluetooth. Some can connect directly o printers via cables or wireless methods. Maximum resolution is measured in Megapixels (Mp). Images can be previewed on screen and kept or deleted as necessary
Many input devices can be adapted to make them easier for people to use.
Adjusted pointer speed to help positioning Speed of mouse can be slowed Speed of click can be adjusted Buttons can be set for left or right handed people Numeric keypad can be set to use as a pointer instead of a mouse Large trackerballs make movement easier Single key strokes can be set up to replace ones like Ctrl Alt Del Concept keyboards can simplify interface Foot mouse allow control with feet.
Demand fast response times. Some games simulate activities like driving or flying, so the input device design can help to make it feel more realistic. The Wii remote uses motion sensing technology and communicates to the computer using Bluetooth so is wireless too. It can be adjusted for left and right handed people, and can also be used as a pointing device using infra-red. Extra devices have been released such as gun, guitar, steering wheel, golf club etc.
ict.com/gcse/hardware/input/miniweb_manu al/keyboard.htm ict.com/gcse/hardware/input/miniweb_manu al/keyboard.htm
1. Describe the input media is used by the following input devices: a)Optical mouse b)Graphics tablet c)RFID 2. Explain the benefits of an ergonomic keyboard compared to a standard keyboard. 3. Identify the forms of input that a PDA accepts. 4. Explain the advantages and disadvantages of each type of mouse / pointing device.
1. Name 2 benefits of Nintendo Wii controllers 2. Name a drawback of Nintendo Wii controllers 3. How can input devices be adapted for people with disabilities? 4. What’s OMR? Where is it used? 5. Name 3 devices that use Automated Input.