SS 1 First Term

Learning Objectives

• Revise all topics of the term.
• Consolidate the parts of the computer system.
• Practise questions on software, the operating system and word processing.
• Prepare for the end of term examination.

Review of the Computer System and History

A computer system has hardware, software and people that work together on data. Data enters as input, is processed, and leaves as output, and results may be stored. Data is a raw fact, while information is data arranged to give meaning.

The computer developed from early counting devices such as the abacus, through Babbage's Analytical Engine and Ada Lovelace's first program, to the electronic computers such as ENIAC. Later the transistor, the integrated circuit and the microprocessor made computers smaller, faster and cheaper.

The system unit holds the motherboard, the processor and the memory. The processor has the control unit, the arithmetic and logic unit and the registers, and these parts work together over the system bus.

Review of Devices, Memory and Software

Input devices enter data and output devices present results. Some output is soft copy on a screen and some is hard copy on paper. Memory is directly used by the processor, while storage holds data permanently, and capacity grows from the bit to the byte, the kilobyte, the megabyte, the gigabyte and the terabyte.

Software is either system software, which runs the computer, or application software, which helps the user do a task. The operating system manages the processor, the memory, the storage and the devices, and it provides the interface the user works with.

A word processor creates and edits text. Text can be typed, formatted and saved, and a document can be printed or sent.

Review of Languages and Programming

A computer language may be low level, such as machine or assembly language, or high level, close to English. A compiler translates a whole program, while an interpreter translates it line by line.

A program is an algorithm written in a language. Programs are built from sequence, selection and iteration, and a simple program can be written in a language such as Python.

Answering Examination Questions

Objective questions reward accuracy, so read every option before choosing. Short answer questions reward precision, so give exactly what is asked. In a difference question write both parts. In a list question number each item so that it can be marked.

Show working in any calculation, and label clearly in any diagram. Plan the last week of revision around the topics that were weakest in the class test.

Practical Work

1. Draw and label the parts of a computer system from memory.
2. Draw the table comparing RAM and ROM from memory.
3. List five functions of an operating system.
4. Write a simple three line program plan using sequence.

Scenario-Based Questions

1. Explain how you would revise ten weeks of work in four evenings.
2. Explain why reading notes once is a weak method of revision and give a better method.
3. A learner says memory and storage are the same thing. Explain the difference.
4. A learner says a compiler and an interpreter do the same job. Explain the difference.
5. Explain why a driver is needed before a printer will work.

Examination and Continuous Assessment Practice

These questions are taken from the First Term examination and Continuous Assessment papers for this class. Answer them in full sentences.

1. A designer is asked how a computer can hold a letter, a photograph and a song. Explain how a computer represents information, why the system uses only two symbols, and show how the letter A and the word CAT are stored.
2. (a) Trace the historical development of calculating devices by highlighting the contributions of the Abacus, John Napier, Blaise Pascal, and Charles Babbage. (b) Explain why Charles Babbage is regarded as the 'Father of Computers'. (c) Convert a storage measurement of 16 Megabits (Mb) into Megabytes (MB), recalling that 1 Byte = 8 bits. Show your workings.
3. (a) Tabulate the major technological components, advantages, and limitations of the First, Second, Third, and Fourth Generations of computers. (b) A legacy file system uses 2,048 Bytes of storage. Convert this value into Kilobytes (KB) and further convert it into bits. Show complete calculations.
4. (a) Classify computers based on operating principles (type) and explain each class with one example: Analog, Digital, and Hybrid. (b) Classify digital computers based on size and capability, describing Microcomputers, Minicomputers, Mainframe computers, and Supercomputers.
5. (a) Define Computer Hardware and categorize it into Input, Output, and Storage components. (b) Explain the primary functions of computer peripheral devices, giving specific attention to Scanners, Plotters, and Projectors. (c) Convert 10 Megabytes (MB) into Kilobytes (KB) and then calculate how many 512-byte blocks can fit into that 10 MB space.
6. (a) Differentiate clearly between Primary Memory and Secondary Storage, comparing RAM and ROM. (b) Perform the following storage scale conversions, showing all intermediate steps: (i) Convert 3 Gigabytes (GB) into Megabytes (MB). (ii) Convert 512 Bits into Bytes. (iii) Arrange the following storage capacities in descending order: 2 TB, 2,048 MB, 500 KB, 4,096 Bytes.
7. A school is about to buy a computer and a vendor claims that only the monitor and keyboard are needed. Explain the four components of a computer system, use the choir analogy to show how they fit together, and explain why the vendor's claim is wrong.
8. A shopkeeper in Lagos still uses a wooden frame with rods and beads, and a surveyor still carries a ruler with sliding scales. Name and describe the early calculating devices, and state who developed the Pascaline and what else the same person gave to modern computing.

LEARNING OBJECTIVES: BY THE END OF THE LESSON STUDENTS SHOULD BE ABLE TO:

Rationale: A computer system has hardware, software and people that work together on data. Understanding review of the Computer System and History, review of Devices, Memory and Software, review of Languages and Programming, answering Examination Questions helps learners use digital technology confidently, safely and responsibly.

Pre-requisite Knowledge: In Week 10, learners studied Computer Languages and Programming, including machine, Assembly, and High-Level Languages, compilers, Interpreters, and Why We Program, a First Taste of Python. The knowledge from that week is used again in this lesson.

Learning Material/Teaching Aid: Whiteboard, markers, computer or laptop where available, printed notes and charts on Revision, practical task sheets, learners' notebooks and pens.

Reference Materials: Digital Technology for Senior Secondary Schools (SS 1); NERDC Digital Technology Curriculum; Digital Technology SS 1 First Term Notes (Week 11); First Term examination and Continuous Assessment question papers.

LESSON DEVELOPMENT

Assignment: i. A designer is asked how a computer can hold a letter, a photograph and a song. Explain how a computer represents information, why the system uses only two symbols, and show how the letter A and the word CAT are stored. ii. (a) Trace the historical development of calculating devices by highlighting the contributions of the Abacus, John Napier, Blaise Pascal, and Charles Babbage. (b) Explain why Charles Babbage is regarded as the 'Father of Computers'. (c) Convert a storage measurement of 16 Megabits (Mb) into Megabytes (MB), recalling that 1 Byte = 8 bits. Show your workings.