Computer Systems Data Representation
- 2. Aims of Lesson 1 To go over the Computer Structure test Begin Unit 3 – Peripherals Discuss the functions of an interface Buffering Data Format conversion Voltage conversion
- 3. Interface A piece of hardware that is positioned between the processor and peripheral The interface allows the processor and peripherals to communicate and compensates for differences between the two, for example, speed INTERFACE
- 4. Functions of the Interface Buffering A part of the interface where data is held temporarily while in transit between the processor and peripheral Processor sends print job to printer Job stored temporarily in buffer Processor get on with other tasks Job is printed when printer is ready
- 5. Other Interface Functions Voltage conversion This is required if the peripheral uses a different voltage from the standard 5V used by the processor Analogue to Digital Conversion Used to convert analogue signals like sound from a microphone into digital 1s and 0s
- 6. Computer Systems Question What is the total addressable memory if you have a 16 bit address bus and an 32 bit data bus? Give 1 advantage and 1 disadvantage of using ASCII over Unicode I have an image of Bart Simpson with a bit depth of 16 bits. How many colours can I represent per pixel How many bits are used to represent true colour List the 3 steps in the Memory Read Operation Name the 3 main types of RAM that can be found in a computer system Name the 3 main buses connecting the processor to input and output
- 7. Aims of Lesson 2 Last Lesson Discuss the functions of an interface Buffering Data Format conversion Voltage conversion Today’s Lesson More functions of an interface Serial to Parallel conversion Status Signals Spoolers
- 8. Other Interface Functions Serial to Parallel Conversion Serial sends the bits for each character one after the other Parallel sends each character along separate lines sumultaneously .i.e data bus 0 1 0 1 1 SERIAL PARALLEL 1 1 1 0 0 SERIAL to PARALLEL conversion
- 9. Status Signals The purpose of a status signal is to determine whether or not a peripheral device is ready to communicate Signals could include Insert paper Printer busy Toner low More printers also show status signals on a LCD panel on the printer
- 10. Spoolers A spooler is a program which carries out a similar function to a buffer The spooler uses an area of the hard disk to temporarily store print jobs The data is held on disk and transferred to the printer gradually Adv Buffer is limited to a fixed size depending on RAM of printer Spooler may be used in a LAN on a dedicated printer server
- 11. Aims of Lesson 3 Last Lesson Discuss the functions of an interface Buffering Data Format conversion Voltage conversion Serial to Parallel conversion Status Signals Spoolers Today’s Lesson Protocols Interface standards Solid state storage Flash cards USB flash memory Advantages of solid state
- 12. Protocols An agreement or standard that is set up between the processor and the peripheral Parity is an example of a protocol used for checking errors Even = adding a bit to each byte of data to make the number of 1s even Odd = adding a bit to each byte of data to make the number of 1s odd 1 001 0011 0 001 0011
- 13. Interface Standards USB 1 = 12Mbps USB 2 = 480Mbs Firewire 800 PCI (peripheral component interface)
- 14. Solid State Storage A storage device that has no moving parts and uses Flash ROM Flash cards USB Flash memory Advantages Physically small Robust with no moving parts Use less power Range of capacities
- 15. Aims of Lesson 4 So Far!! Discuss the functions of an interface Buffering Data Format conversion Voltage conversion Serial to Parallel conversion Status Signals Spoolers Protocols Interface standards Solid state storage Flash cards USB flash memory Advantages of solid state Today’s Lesson Current Interface Trends Increasing Interface speeds Wireless communication between peripherals and CPU Development Trends in Backing Storage Blu-ray Holographic storage Reduced Physical size Lower storage cost Class Quiz to revise Peripherals
- 16. Current Interface Trends Increasing speeds USB1 = 12Mbps USB2 = 480Mbps Wireless Communication Using Bluetooth and Wifi radio waves to connect peripherals to the CPU
- 17. Development Trends in Backing Storage Blu-ray Used for storing high definition video BD-ROM, BD-R and BD-RE Laser beam in the drive is coloured blue, producing a narrower beam and is able to store more data Holographic storage Uses laser beams to record data through the full depth of the device rather than just the surface Reduced Physical size Lower cost per unit of storage
- 18. Peripherals Revision Quiz What is an interface? Give 3 functions of an interface What is the difference between buffering and spooling? Give 1 advantage of spooling over buffering What is a status signal? Give 1 example to reinforce your answer Parity is an example of a protocol. What is even parity?
- 19. Peripherals Revision Quiz Give 3 advantages of using a solid state storage device over non solid state Give 2 current interface trends Give 3 trends in backing storage at the present time