Computer Input Output

 

• Data Processing Cycle: The computer receives data as input which processes and produces information as output. This information can then be used as input along with other data in a new process (see figure below). This is called a data processing cycle.

 • The computer consists of: The Central Unit, the input units and the output units

• Input units: We enter data from them into the Computer. Input units are:

1. Keyboard

2. Mouse

3. Scanner

4. Digital camera

5. Microphone

• Output units: From these we get the results of processing the information from the computer. Output units are:

1. Screen

2. Printer

3. Speakers

The touch screen is an input and output unit

• There are 4 types of printers:

1. Impact printers: are slow, noisy and are used to print duplicate receipts

2. Inkjet printers. They are cheap but they run out of ink easily (we can not print many pages) and are relatively slow

3. Laser printers. They are more expensive but their ink lasts longer (we can print many pages) and they are fast

4. 3D printers: print 3D objects

• Inside the Central Unit are: The Central Processor and the RAM

• RAM temporarily stores information and data, these are transferred to the Central Processor which processes them. The results of this processing are transferred and stored in RAM temporarily or in other storage media permanently.

• Permanent Storage Units in order of capacity

Hard drive

Flash disk

DVD

CD

Floppy disk (not used)