Basic 7 · Computing · Components of Computer
Output Devices and Storage Devices
In this topic you will examine the uses of output devices and compare storage devices such as hard drives, solid-state drives, flash drives, memory cards and optical discs.
By the end of these notes you should be able to:
- Identify output devices and explain their uses
- State the advantages and disadvantages of output devices
- Compare storage devices by capacity, speed and portability
What you already know
- Input devices and their uses
Copy everything that has a blue line on its left into your notebook. The other parts are for reading.
Lesson 1
- Strand
- Introduction to computing
- Sub-strand
- Components of Computer
- Indicator
- B7.1.1.1.3 – Examine the uses of the output devices:
Introduction
After a computer processes data, it must show you the result. A report on a screen, a printed result slip and the sound from speakers all come from output devices.
1. What Is an Output Device?
Output device: Hardware that presents processed information from the computer to the user in a form they can see, hear or touch.
2. Soft Copy and Hard Copy
Output on a screen or through speakers is called soft copy; it is temporary and disappears when the device is switched off. Output on paper or another physical material is called hard copy; it can be carried, filed and read without a computer.
3. Common Output Devices
| Device | Use |
|---|---|
| monitor (screen) | displays text, pictures and video |
| printer | produces hard copies on paper |
| speakers and headphones | produce sound |
| projector | displays the screen on a large wall or board |
| plotter | prints large drawings such as building plans and maps |
| 3D printer | builds solid objects layer by layer |
| wearable displays | smartwatches and smart glasses show information on the body |
4. Types of Printers
| Printer | How it works | Advantage | Disadvantage |
|---|---|---|---|
| inkjet | sprays tiny drops of ink | cheap to buy; good colour | ink is expensive; slower |
| laser | uses toner and a laser drum | fast and sharp; cheap per page | expensive to buy |
| dot matrix | pins strike an inked ribbon | can print carbon copies | noisy; poor quality |
5. Choosing an Output Device
Choose output devices to suit the user and the task. A teacher showing slides to a class needs a projector. A school printing hundreds of report cards needs a fast laser printer. A visually impaired person may use speakers with screen-reading software or a Braille display. Large architectural drawings need a plotter. Good choices save time, money and effort.
6. Output Devices in Everyday Life
Output devices are found well beyond the computer laboratory. Electronic billboards along major roads display adverts. Screens at banks and hospitals show queue numbers. Mobile phones vibrate and ring to alert us. Receipt printers at supermarkets print bills. Recognising these devices helps us understand how widely computers are used in our communities.
New words
- output device
- Hardware that presents processed information.
- soft copy
- Output shown on a screen or as sound.
- hard copy
- Output printed on paper.
- plotter
- A device for printing large drawings.
Summary
- Output devices present results to the user as soft copy or hard copy.
- Monitors, printers, speakers, projectors and plotters are common output devices.
- Choose output devices according to the task and the user's needs.
Class activity: Output Device Study
- Study printed photographs of output devices in use, including wearable displays.
- Demonstrate the use of a monitor and printer in the laboratory.
- Record one advantage and one disadvantage of each device.
You need: Computer monitor, Printer, Printed photographs of wearable displays
Exercises
Answer in your exercise book first, then check your answers.
1. Which device produces hard copy?
- A. Printer
- B. Monitor
- C. Speaker
- D. Projector
Show answer
Answer: PrinterPrints on paper.2. Large building plans are best printed with a…
- A. plotter
- B. dot matrix printer
- C. speaker
- D. scanner
Show answer
Answer: plotterLarge drawings.3. Soft copy is output shown on a screen.
- A. True
- B. False
Show answer
Answer: TrueIt is temporary.4. A printer that sprays tiny drops of ink is an ______ printer.
Show answer
Answer: inkjetInk spray.5. State the difference between soft copy and hard copy.
Show answer
Answer: Soft copy is temporary output on a screen or as sound; hard copy is permanent output on paper.Screen vs paper.6. Explain why a school might choose a laser printer instead of an inkjet printer.
Show answer
Answer: Laser printers print faster and cost less per page, which suits printing many documents.Speed and cost.
Lesson 2
- Strand
- Introduction to computing
- Sub-strand
- Components of Computer
- Indicator
- B7.1.1.1.4 – Examine full-sized external hard drives hard drive speed disk caching, Storage portable hard drives, Optical Discs and Drives
Introduction
When you save your class project, it must be kept somewhere safe so you can open it next week. Storage devices keep data even when the computer is switched off.
1. Primary and Secondary Storage
Primary storage (main memory) includes RAM and ROM. RAM holds data while the computer is working but loses it when power goes off. Secondary storage keeps data permanently until it is deleted. Hard disk drives, solid-state drives, flash drives, memory cards and optical discs are secondary storage devices.
2. Hard Disk Drives and Solid-State Drives
A hard disk drive (HDD) stores data magnetically on spinning metal platters read by a moving head. Speed depends on how fast the platters spin: a common desktop drive spins at 7,200 revolutions per minute (RPM). A solid-state drive (SSD) has no moving parts and stores data on memory chips, so it is much faster, quieter and less easily damaged. Drives may be internal (inside the computer) or external (connected by USB). Full-sized external drives are larger and need their own power; portable external drives are small and powered by USB.
3. Disk Caching
Disk cache: A small amount of fast memory on or near a drive that holds recently used data so it can be read again quickly.
When you open the same file often, the computer can fetch it from the cache instead of searching the whole disk, which makes the system faster.
4. Comparing Storage Devices
| Device | Typical capacity | Typical speed | Notes |
|---|---|---|---|
| SD memory card | 8 GB–512 GB | about 12.5 MB/s and above | used in cameras and phones |
| USB flash drive | 8 GB–256 GB | 20–200 MB/s | small and portable |
| HDD (7,200 RPM) | 500 GB–8 TB | 80–160 MB/s | cheap per gigabyte |
| SSD | 128 GB–4 TB | 500 MB/s to over 3,000 MB/s | very fast; no moving parts |
| CD | 700 MB | slow | optical; read by laser |
| DVD | 4.7 GB | slow | optical; films and software |
| Blu-ray disc | 25 GB–50 GB | slow | high-definition video |
5. Caring for Storage Devices
Keep storage devices away from heat, water, dust and strong magnets. Always use "Safely Remove Hardware" or "Eject" before unplugging a flash drive, so files are not damaged. Hold optical discs by the edges and store them in cases. Back up important files on more than one device or in cloud storage, because any device can fail.
New words
- secondary storage
- Storage that keeps data permanently.
- SSD
- A solid-state drive with no moving parts.
- RPM
- Revolutions per minute, the spin speed of a hard disk.
- backup
- A copy of data kept in case the original is lost.
Summary
- Secondary storage keeps data even when power is off.
- HDDs use spinning platters; SSDs use memory chips and are faster.
- Storage devices differ in capacity, speed and portability; always back up data.
Class activity: Storage Comparison
- Examine a USB flash drive, a hard disk drive and a memory card.
- Compare their size, likely capacity and speed using the table.
- Recommend the best device for storing a school's examination records and explain why.
You need: USB flash drive, Hard disk drive, Memory card
Exercises
Answer in your exercise book first, then check your answers.
1. Which is a secondary storage device?
- A. Flash drive
- B. Monitor
- C. Keyboard
- D. Speaker
Show answer
Answer: Flash driveStores data permanently.2. Which storage device has no moving parts?
- A. SSD
- B. HDD
- C. DVD drive
- D. CD drive
Show answer
Answer: SSDUses memory chips.3. RAM loses its data when the power goes off.
- A. True
- B. False
Show answer
Answer: TrueIt is volatile.4. A copy of data kept in case the original is lost is a ______.
Show answer
Answer: backupSafety copy.5. Give two advantages of an SSD over an HDD.
Show answer
Answer: It is faster and less easily damaged (also quieter and uses less power).Any two.6. Explain why you should eject a flash drive before removing it.
Show answer
Answer: The computer may still be writing data; removing it suddenly can damage or corrupt files.Data safety.
Homework
- Find the storage capacity of three devices at home, such as a phone, a memory card and a flash drive.