Hardware & Storage_v1

Hardware & Storage_v1

1. Output

   • Visual display unit
     • LED, LCD, CRT
   • Printer
     • Laser
       • Adv - high speed printing (ppm), high quality as compared to dot matrix printer
     • Inkjet
       • Adv - high resolution (high dpi)
         • Resolution - how many pixel per square inch
     • Thermal
       • Adv - low cost printing. Disadv - the ink dissappear after some time
     • Impact/Dot Matrix
       • Adv - can print multiple pages at the same time. Disadv - lower quality of printing
     • Plotter
       • Adv - can print high quality picture over a large area. Diadv - high cost of printing
   • Speaker

2. Input

   • The data or instructions you type into the computer.

3. Input Devices

   • Keyboard
     • Types: Standard, Ergonomic, Wireless and Braille
       • 1) Standard: Contains own chips. 2) Ergonomic: Provide comfort and safety. 3) Wireless: Transmit data using wireless technology such as radio waves. 4) Braille: Allow visually-impaired users to enter data(unique dots to differentiate different characters.
   • Mouse
     • Uses: Select options, position cursor, draw shapes.
       • Types: Ball bearing, optical and tracker ball
   • Magnetic Strip Reader
     • Magnetic tape stuck on the surface of a tag or card
       • Adv: Simple and cheaper to produce & stores a large no. of characters. Disadv: Magnet can change or erase data.
   • Barcode Readers
     • Barcode contains country of origin, manufacturer and item code.
       • Adv: Less error when entering data, faster data entry. Disadv: Barcodes only be read by machine, only numbers can be coded this way
   • OCR
     • Optical Character Recognition
       • Reads typewritten docs and convert into a form that can be edited by computer
         • Immigration checkpoint to scan passport
   • OMR
     • Optical Mark Recognition
       • Uses light to scan the marking and convert it into data.
         • MCQ/ Voting ballot
   • MICR
     • Magnetic Ink Character Reader
       • Ink is magnetized when document pass through the reader so the the character shapes can be recognized electrically.
         • Used in banks to process cheques
           • Lower left characters are cheque number. Bank number and account number.
       • Adv: Documents can be read when folded or written on. Disadv: Readers are expensive and only certain fonts are acceptable.
   • EPOS/EFTPOS
     • Electronic Point Of Sale/ Electronic Fund Transfer at Point Of Sale.
       • EPOS: Cash register which act as the terminal connected to computerised system and provide customer itemised bills
       • EFTPOS: Identical to EPOS but with extra features. They are able to tarnsfer funds from bank account directly to a store's debit card
       • Adv: Faster mode of payment Disadv: encourage people to spend more.
   • Scanner
     • Read data/ info form hardcopy source
       • Flatbed, Sheetfeed, Handheld
   • Camera
     • Digital Camera
       • Used to store pics in digital form.
         • Adv: View/edit pics immediately, easily transferred to computer(digital form)
     • Web Camera
       • Capture still images/ video images
         • Used for video conferencing/ check traffic condition

4. Process

   • Processing is handled by CPU. There are 3 components in CPU
     • ALU - Arithmetic Unit where calculation is done
     • CU - control unit that controls peripherals or devices that are connected to the computer
     • IAS - intermediate area storage that store the data temporarily

5. Types of Computer System

   • Mainframes
     • It is used when there are a lot of input and output needed at the same time eg. bank trasnaction
   • Workstation
   • Microcomputer
   • Supercomputer
     • It is used when there are a lot of calculation eg weather forecasting
   • Laptop
   • PDA

6. Storage

   • 3 types of storage
     • Optical eg. DVD, CD, Blu-ray
       • Adv - data is not easily deleted
     • Magnetic eg. hard drive, cassette
     • Solid state eg. flash memory, memory card
       • Adv - portable because it is smaller in size. Disadv- expensive