Macquarie Fields College of TAFE

1. Macquarie Fields College of TAFE 3 Version 2 – 13 March 2000 3 - HARDWARE

2. Minicomputers Powerful General Purpose 50/100 MIPS Microcomputers Single silicon chip (CPU) Desktop/Laptop 5/20 MIPS Super computers 250 MIPS Multiple Processors Mainframes Large & Fast Networked 100/200 MIPS Macquarie Fields College of TAFE Types of Computers

3. Macquarie Fields College of TAFE Issues Surrounding Computers • Cost • Security/Passwords • Customisation • Ease of use • Performance

4. Macquarie Fields College of TAFE Monitors (VDU) • Another term for display screen. The term monitor, however, usually refers to the entire box, whereas display screen can mean just the screen. In addition, the term monitor often implies graphics capabilities. • There are many ways to classify monitors. The most basic is in terms of colour capabilities, which separates monitors into three classes.

5. Macquarie Fields College of TAFE Monitors - Colour • Monochrome Monochrome monitors actually display two colours, one for the background and one for the foreground. The colours can be black and white, green and black, or amber and black. • Gray-scale A gray-scale monitor is a special type of monochrome monitor capable of displaying different shades of gray.

6. Macquarie Fields College of TAFE Monitors - Colour • ColourColour monitors can display anywhere from 16 to over 1 million different colours. Colour monitors are sometimes called RGB monitors because they accept three separate signals -- red, green, and blue.

7. Macquarie Fields College of TAFE Monitors - Size • screen sizes are measured in diagonal inches, the distance from one corner to the opposite corner diagonally. • A typical size for small VGA monitors is 14-15 inches. • Monitors that are 16 or more inches diagonally are often called full-page monitors.

8. Macquarie Fields College of TAFE Monitors - Resolution • The resolution of a monitor indicates how densely packed the pixels are. In general, the more pixels (often expressed in dots per inch), the sharper the image. • Most modern monitors can display 1024 by 768 pixels, the SVGA standard. Some high-end models can display 1280 by 1024, or even 1600 by 1200.

9. The printer uses a parallel connection that has 25 pins. This is used so that the information can be processed at 8 bits (1 byte) at a time. Macquarie Fields College of TAFE Printers A printer is a peripheral device that is attached to a computer and is used to transfer data from the computer to paper producing a hard copy.

10. Impact Dot Matrix Daisy Wheel Non-impact Laser Ink jet/bubble jet Plotter Macquarie Fields College of TAFE Types of Printers

11. Macquarie Fields College of TAFE Which printer should I get? Printers are designed for just about everybody and everything – from black and white to architectural design, colour printouts or high quality designs. Let’s look at the advantages and disadvantages of the types already discussed.

12. Macquarie Fields College of TAFE Advantages/Disadvantages of Different Printers LASER PRINTER • AdvantagesHigh quality printoutsFastReasonably pricedQuiet • DisadvantagesCostly to maintain - Expensive to replace cartridges and the number of output is half to inkjetBulky in size

13. Macquarie Fields College of TAFE Advantages/Disadvantages of Different Printers INK JET/BUBBLE JET • AdvantagesReasonable qualityCost EffectiveQuietFast • DisadvantagesInk will run if wetCartridges can be expensive to replace

14. Macquarie Fields College of TAFE Advantages/Disadvantages of Different Printers PLOTTER • AdvantagesCan print larger than A3 paperCan print in thin intricate lines used for 3D, map and design drawings • DisadvantagesExpensive to purchaseSlow to print

15. Macquarie Fields College of TAFE Advantages/Disadvantages of Different Printers DOT MATRIX/DAISY WHEEL • Advantages- Can print multiple copies as the impact printer strikes carbonised sets • Can print continuous paper • Disadvantages- Slow- Noisy- Ribbons are becoming more expensive as machines are becoming more extinct

16. Macquarie Fields College of TAFE ASCIIAmerican Standard Code for Information Interchange • Represents all letters, numbers and characters on keyboards • 01000001 = A • 01010100 = T • 8 bits = 1 byte = 1 character

17. Macquarie Fields College of TAFE ASCIIAmerican Standard Code for Information Interchange • There are 256 possible combinations of ASCII code. The ASCII character set shown here represents the capital letter ‘A’ as 65, ‘T’ as 84, lower ‘a’ as 97 and ‘½’ as 171.

18. Macquarie Fields College of TAFE ASCIIAmerican Standard Code for Information Interchange

19. Macquarie Fields College of TAFE ASCIIAmerican Standard Code for Information Interchange { 0 1 0 0 0 0 1 0 1 Byte 1 Bit (Binary Digit)

20. Macquarie Fields College of TAFE MemoryUnits of Measurement 1 BIT = 0’s or 1’s 8 BITS = 1 BYTE (1 character) 1,000 BYTES = 1 KILOBYTE (1 thousand) 1,000 KILOBYTES = 1 MEGABYTE (1 million) 1,000,000 1,000 MEGABYTES = 1 GIGABYTE (1 billion) 1,000 million 1,000,000,000 1,000 GIGABYTES = 1 TERABYTE (1 trillion) 1 million million (1012) ÷

21. Macquarie Fields College of TAFE Security Refers to techniques for ensuring that data stored in a computer cannot be read or compromised. Most security measures involve data encryption and passwords. Data encryption is the translation of data into a form that is unintelligible without a deciphering mechanism. A password is a secret word or phrase that gives a user access to a particular program or system.

22. Macquarie Fields College of TAFE Passwords A secret series of characters that enables a user to access a file, computer, or program. On multi-user systems, each user must enter his or her password before the computer will respond to commands. The password helps ensure that unauthorized users do not access the computer. In addition, data files and programs may require a password.

23. Macquarie Fields College of TAFE Security/Passwords • Encryption • Passwords • Security Levels • Attributes • Backups