Input, Output and Storage Devices

Input Device

Any device that allows you to put information from the outside world into a computer system

Examples

1. Mouse

2. Keyboard

3. Microphone

4. Sensor

Output Device

Any device that can take data stored in digital forma and convert it into another format that humans can process such as sound, images or vibrations

Examples

1. Monitor

2. Printer

3. Speaker

4. Headphone

Storage Device

Any device used for temporary/permanent storage of data; can be internal or external

Examples

1. CD

2. DVD

3. Blu-Ray

4. USB

5. Flash-drive

Magnetic Flash and Optical Storage

Drive

Devices that reads/writes data from secondary storage

Media

What the data is actually stored on

Secondary Storage

Non-volatile

Large storage capacity

Long term storage of data

Optical Storage

Positives:

• Cheap

• Lightweight

• Portable

Negatives:

1. Slow access times (Has to wait 1 full revolution to find data)

2. Prone to scratches

Magnetic Storage

Positives:

• Cheap

• Large Capacity

Negatives:

1. Slow access times

2. Fragile

Solid State Storage

Positives:

• Durable

• Fast access times

Negatives:

1. Cost

2. Limited read/writes

RAM and ROM

RAM

Temporary storage of instructions and data

Volatile

• RAM stores data that is currently being used by the computer, such as open applications and files

• The data in RAM can be read from and written to by the processor, allowing for fast data access and manipulation

Much faster to access than hard disk because it is close proximity to CPU

ROM

• ROM stores the BIOS (Basic Input/Output System) or firmware that is used to start up the computer and initialise the hardware components. This data is essential for the computer to function and needs to be preserved even when the computer is turned off

• ROM is non-volatile, meaning it retains its contents even when the computer is turned off. As its name suggests, data stored in ROM can be read by the computer but not written to or modified

• In all types of computers, ROM is essential for system startup. E.g. in mobile devices, ROM might contain the bootloader that starts the device and loads the operating system

Bootstrap

Power on self-test:

Sends signal to all connected components to wake them up

Makes the CPU aware of its existence