Basic 7 · Computing · Components of Computer
Fourth-Generation Computers and Input Devices
In this topic you will discuss the features of fourth-generation computers and how they changed the world, and identify input devices, their uses, advantages and disadvantages.
By the end of these notes you should be able to:
- Describe the features of fourth-generation computers
- Identify manual and automatic input devices and their uses
- State the advantages and disadvantages of common input devices
What you already know
- Generations of computers and parts of a computer (Upper Primary)
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
- B7.1.1.1.1 – Discuss the fourth-generation computers
Introduction
Early computers filled whole rooms and only governments could afford them. Then, in the 1970s, scientists put the whole brain of a computer onto one tiny chip. This was the beginning of the fourth generation, and it brought computers into homes, schools and pockets.
1. The Generations in Brief
| Generation | Period (approx.) | Main technology |
|---|---|---|
| first | 1940s–1950s | vacuum tubes |
| second | 1950s–1960s | transistors |
| third | 1960s–1970s | integrated circuits (ICs) |
| fourth | 1971–present | microprocessors using very large scale integration (VLSI) |
| fifth | present and future | artificial intelligence (AI) |
2. The Microprocessor
Microprocessor: A single chip that contains the central processing unit (CPU) of a computer.
Very large scale integration (VLSI) made it possible to place thousands, and later billions, of transistors on one silicon chip. The Intel 4004, released in 1971, is often called the first commercial microprocessor. Because the CPU fitted on one chip, computers became much smaller, faster and cheaper.
3. Features of Fourth-Generation Computers
| Feature | Effect |
|---|---|
| microprocessors and VLSI circuits | small size and high speed |
| low cost | personal computers (PCs) became affordable |
| large memory and storage | could store and process large amounts of data |
| graphical user interfaces (GUI) | easy to use with a mouse, icons and windows |
| networking and the internet | computers could share information worldwide |
| portable devices | laptops, tablets and smartphones |
| low power use and little heat | more reliable than earlier generations |
4. Examples and Impact
Fourth-generation computers include the IBM Personal Computer (1981), the Apple Macintosh (1984), modern desktop and laptop computers, tablets and smartphones. They changed how people work, learn, bank and communicate. In Ghana today, mobile money, online school registration, hospital records and supermarket tills all depend on fourth-generation technology.
5. Limitations
Even powerful fourth-generation computers have limits. They need electricity, can be attacked by viruses and hackers, may become outdated quickly and produce e-waste when discarded. They also only follow the instructions in their programs. The fifth generation aims to build computers that can learn and make decisions using artificial intelligence.
6. Fourth-Generation Computers in Everyday Ghana
Look around and you will find fourth-generation computers everywhere: the point-of-sale machine at a filling station, the ATM at the bank, the laptop in the head teacher's office, the electronic voting equipment used to verify voters, and the smartphone used to pay with mobile money. Each contains a microprocessor that follows instructions millions of times per second.
New words
- microprocessor
- A chip containing the computer's CPU.
- VLSI
- Very large scale integration: many transistors on one chip.
- GUI
- Graphical user interface using icons, windows and a pointer.
- personal computer
- A computer designed for use by one person.
Summary
- Fourth-generation computers use microprocessors built with VLSI technology.
- They are small, fast, cheap, reliable and easy to use, with GUIs and networking.
- Desktops, laptops, tablets and smartphones are fourth-generation computers.
Class activity: Generation Timeline
- Study printed photographs of computers from different generations.
- Arrange them in order on a timeline and label the main technology of each.
- Inspect a desktop computer and a processor and explain why the fourth generation is smaller and faster.
You need: Desktop computer, Computer processor, Printed photographs of computer generations
Exercises
Answer in your exercise book first, then check your answers.
1. Fourth-generation computers mainly use…
- A. microprocessors
- B. vacuum tubes
- C. transistors only
- D. punched cards
Show answer
Answer: microprocessorsVLSI chips.2. VLSI stands for…
- A. very large scale integration
- B. very light system input
- C. virtual large storage interface
- D. visual layout screen interface
Show answer
Answer: very large scale integrationMany transistors on one chip.3. Smartphones are examples of fourth-generation computers.
- A. True
- B. False
Show answer
Answer: TrueThey use microprocessors.4. A single chip that contains the CPU is a ______.
Show answer
Answer: microprocessorThe computer's brain on a chip.5. State four features of fourth-generation computers.
Show answer
Answer: Microprocessors, small size, low cost, GUI (or networking, large storage, portability).Any four.6. Explain how the microprocessor made personal computers possible.
Show answer
Answer: Putting the whole CPU on one cheap, small chip reduced the size and cost of computers so that individuals could own them.Size and cost.
Lesson 2
- Strand
- Introduction To Computing
- Sub-strand
- Components of Computer
- Indicator
- B7.1.1.1.2 – Demonstrate understanding in the use of input devices
Introduction
A computer cannot read your mind. Every word you type, every click you make and every barcode scanned at the supermarket enters the computer through an input device.
1. What Is an Input Device?
Input device: Hardware used to enter data and instructions into a computer.
2. Manual and Automatic Input Devices
| Type | Meaning | Examples |
|---|---|---|
| manual | a person enters the data by hand | keyboard, mouse, touchscreen, joystick, graphics tablet |
| automatic | the device captures data directly, with little human effort | barcode scanner, QR code reader, OCR scanner, MICR reader, biometric fingerprint reader, sensors |
3. Common Input Devices and Their Uses
| Device | Use |
|---|---|
| keyboard | typing text and numbers, giving commands |
| mouse | pointing, clicking, dragging and selecting |
| touchscreen | entering data by touching the screen, e.g. phones and ATMs |
| microphone | recording sound and voice commands |
| webcam and digital camera | capturing pictures and video |
| scanner | converting printed documents into digital images |
| barcode reader | reading product codes at shops |
| fingerprint reader | identifying people, e.g. Ghana Card registration and phones |
4. Advantages and Disadvantages
| Device | Advantage | Disadvantage |
|---|---|---|
| keyboard | accurate for typing text | slow for people who cannot type well |
| mouse | quick and easy for pointing | needs a flat surface |
| touchscreen | no extra device needed | screen gets dirty; not good for long typing |
| barcode reader | very fast and accurate | damaged barcodes cannot be read |
| microphone | hands-free input | background noise causes errors |
5. Choosing the Right Input Device
The best input device depends on the task. A cashier at a busy supermarket needs a barcode reader to serve customers quickly. A secretary typing letters needs a keyboard. A graphic designer drawing logos may prefer a graphics tablet. A person with a disability may use voice input or special keyboards. Automatic devices reduce human error and save time when large amounts of data must be entered.
6. Input Devices for People with Disabilities
Special input devices allow everyone to use computers. A person who cannot see well can use voice recognition to give commands. A person who cannot use their hands may use a head pointer, an eye-tracking camera or a mouth-operated switch. Large-key keyboards help young children and people with weak eyesight. These devices are called assistive technology, and they make computing inclusive.
New words
- input device
- Hardware used to enter data into a computer.
- barcode
- A pattern of lines that stores product information.
- biometric
- Using body features, such as fingerprints, for identification.
- OCR
- Optical character recognition: reading printed text into a computer.
Summary
- Input devices enter data and instructions into the computer.
- They are manual (keyboard, mouse) or automatic (barcode reader, sensors).
- Each device has advantages and disadvantages; choose according to the task.
Class activity: Input Device Stations
- Use a keyboard, a mouse and, if available, a barcode scanner.
- Classify each as manual or automatic.
- Record one advantage and one disadvantage of each device.
You need: Keyboard, Mouse, Barcode scanner
Exercises
Answer in your exercise book first, then check your answers.
1. Which is an input device?
- A. Keyboard
- B. Monitor
- C. Printer
- D. Speaker
Show answer
Answer: KeyboardIt enters data.2. A barcode reader is an example of…
- A. an automatic input device
- B. an output device
- C. a storage device
- D. a manual input device
Show answer
Answer: an automatic input deviceIt reads data directly.3. A fingerprint reader is a biometric input device.
- A. True
- B. False
Show answer
Answer: TrueIt reads body features.4. Hardware used to enter data into a computer is an ______ device.
Show answer
Answer: inputData goes in.5. Differentiate between manual and automatic input devices with one example each.
Show answer
Answer: Manual: data entered by a person, e.g. keyboard. Automatic: device captures data directly, e.g. barcode reader.With examples.6. Why do supermarkets use barcode readers instead of keyboards at the checkout?
Show answer
Answer: Barcode readers enter product details faster and more accurately than typing, reducing queues and errors.Speed and accuracy.
Homework
- List five input devices you have seen in your community and say where each is used.