Peripherals Flashcards
(35 cards)
What is a buffer?
- Area of memory (RAM) in the interface temporarily storing data being transferred between computer and peripheral device receiving data
- Compensates for any difference in their speeds, e.g. a printer buffer.
Describe how a printer spooler works
- CPU sends print jobs to fast backing storage
- Print jobs are stored temporarily in a queue
- Jobs are then sent to the printer as it becomes available
Define interface
X
Describe how a buffer will increase system performance
- Buffers compensate for the difference in speed of operation between the fast processor and slower system components, such as peripherals
- Buffers can receive whole blocks of data, from the processor, which wait there on a temporary basis, until they can be processed by the slower peripheral device
- This frees up the processor to carry out other tasks
What is a printer spooler?
- A printer spooler is a program that uses fast backing storage such as hard disc for the temporary storage of print data.
- This is printed as a background task while the user continues his/her work - the foreground task.
Describe one situation in which a spooler would be used in preference to a buffer
- When the printer is accessed over a network & large print files are being dealt with or
- When advanced management of print jobs is required, such as ordering or costing
What appropriate characteristics determine hardware selection?
- Resolution
- Capacity
- Speed
- Cost
- Compatibility
The band Atomic Heatwave has just finished filming a video for their latest single at a castle. State an item of hardware required to transfer the digital video from the camera to the computer.
- USB port / card / cable or
- FireWire port / card / cable or
- Video capture card or
- Bluetooth card / dongle
Connie buys a new web design package. She finds it will not run on her computer. Suggest reasons for this.
- Not enough main memory capacity
- Not enough backing storage capacity
- Operating System compatibility issues
- Graphic card does not contain necessary functions to run package
- Plug ins required e.g. for moving images
Describe three hardware requirements of a computer system, which is to be used for video editing. Include appropriate units.
- RAM - 512Mb+ so that the clips can be viewed more smoothly or realistically
- Backing storage - 80Gb+ (video projects are large files even under compression)
- Processor - 2GHz+ to ensure computer can cope with large projects with many frames
A large number of pictures are stored on a hard disk. The combined size of all thy pictures is 3GB. You can use a Solid-state Storage Device or Re-Writable DVD to take all the photographs to the chemist shop for printing. Provide a justification for using either of them.
- Solid-state Storage Device - more physically robust than DVD
- DVD-RW - media relatively inexpensive
Give two examples of Solid State Storage Devices
- Digital camera flash card storage
* USB memory sticks
Give three advantages of Solid State Storage Devices
- Small size
- Speed of data transfer
- No moving parts which could wear out and break down
What is Interface?
- Interface is the hardware (and associated software) needed to allow communication between the CPU and peripheral devices and to compensate for any differences in their characteristics.
Functions of an Interface
- Buffering - holding data temporarily while in transit between the CPU and peripheral device
- Data Conversion - changing data into a form the CPU can understand and vice-versa - protocol conversion e.g. serial to parallel, voltage conversion
- Handling Status Information - to show whether the device is ready to receive or send data e.g. printer ready or out of paper
Serial and Parallel Transmission of data between devices
- Serial Data Transmission - sends the bits of the data one after each other along the same data line. Relatively slow but more efficient over long distances.
- Parallel Data Transmission - sends the bits of data along separate lines at the same time. This is fast but only suitable for short distances.
James wants to make copies of some photographs. He intends to use a scanner to capture the photographs & an inkjet printer for the final images. Describe one technical characteristic that the printer should have. Justify your answer.
- High resolution (of at least 1200 dpi) - to match the resolution of the scanned image
- High bit depth (of at least 24 bits) - to match the real life (true) colour of the scanned image
- Large buffer - as the print jobs are large (photos have a large file size), & will have to free up the CPU to carry out other tasks
- Correct interface - to connect to James’ computer
- Speed of printing(ppm) - may want to print a number of photos or large photos quickly
Helen is trying to buy a new computer. She will be creating & using several very large spreadsheet files with complex calculations. She has been reading the following two advertisements.
* Lynx 983 - 3.1 GHz AtheleteII Processor, 512 Mb RAM, 120 Gb Hard Disc, 1.44 Mb Floppy Drive, DVD-ROM Drive (CD-ROM compatible)
* Ruath CM - 2.9 GHz MDA4 Processor, 512 Mb RAM, 32 Mb Cache, 100 GB Hard Disc, DVD/CD-RW Combination Drive
If the ability to back-up data is the most important factor for choosing a new computer, which computer would you suggest Helen buys? Give two reasons for your choice.
- The Ruath CM should be chosen because
- It has dual DVD/CD-RW drive. This would allow regular backup to CD-RW
- The Lynx has a floppy drive (its storage capacity too small for purpose) & a DVD-ROM (non-writable storage)
Resolution & capacity are important features of digital cameras.
(a) Explain the terms ‘resolution’ & ‘capacity’ in relation to digital cameras.
(b) Describe how the resolution of a camera affects its capacity.
(a) Resolution = number of pixels used to store image in given area e.g. number of dots per inch.
Capacity = amount of memory in the camera which affects number of pictures which can be stored.
(b) Higher the resolution the more memory required to store one picture so fewer pictures can be stored, or the storage capacity will need to be increased.
A high resolution scanner is used to capture photographs onto a computer. Describe four hardware features of a scanner other than resolution.
- Bit depth - the number of bits used to represent the colour of a pixel, which defines the number of colours available
- Type of interface - serial USB, Parallel
- Size of scanner surface - A3, A4, handheld etc.
- Scanning speed - lines per second
Vanessa buys a 2 Gb USB pen drive, a solid state storage device, \7 connects it to the USB port on her computer. The manufacturer claims that data could be transferred at rates up to 480 megabits per second. The actual transfer rate is 125 megabits per second. Suggest the reasons for this.
(1) Stick may be USB2, but computer only has USB1 interface, or USB1 does not support 480 mbps.
(2) Computer may be multi-tasking - busy doing other tasks.
Hamish would like to purchase a new portable MP3 player so he can listen to music whilst jogging. He knows that some MP3 players make use of solid state storage, whilst others use hard disc to store music. Hamish decides to purchase a Mp3 player that makes use of solid state storage. Apart from size & cost, give three advantages to Hamish in choosing this type of portable MP3 player rather than a player that uses a hard disc.
- It will not skip whilst he is jogging as robust & no moving parts
- It uses less power which increases playback time
- It has faster access time
Customers bring their image files into the shop on flash cards & CD-R. Peter has to be able to read the files from these different formats. Explain advantages of each format over the other for the customer.
- Flash card
(1) Contents can be easily edited
(2) Higher Capacity than CD-R
(3) Can be read by printer
(4) Does not need computer to write to it - CD-R
(1) Cheaper to buy
(2) Cannot be changed once written
Lauren buys a new digital camera. It stores its images on a flash card & has a standard interface. Describe two benefits of using a camera with a flash card.
(1) It is removable& can be read directly by an appropriate computer system or printer.
(2) More than one flash card could be carried allowing more phootos on one trip.
