SS 1 First Term

Learning Objectives

• Name the early calculating devices in order.
• State the contributions of Charles Babbage and Ada Lovelace.
• Describe the first electronic computers.
• Explain how transistors and integrated circuits changed computing.

Early Calculating Devices

People invented tools for calculation long before electricity. The need to calculate is as old as trade itself. The abacus, dating back to around 2400 BC, is one of the oldest known calculating tools. It consists of a wooden frame with rods and beads. The user moves beads to represent numbers and performs addition, subtraction, multiplication, and division. Abacuses were used in ancient Mesopotamia, China, Egypt, and Rome. Even today, some shopkeepers in parts of Asia still use an abacus because it is fast and reliable when the operator is skilled.

In 1617, John Napier invented a set of numbered rods called Napier's Bones that made multiplication easier by breaking it into simpler additions. Later, the slide rule, invented around 1622 by William Oughtred, used sliding scales to perform multiplication, division, and even roots. Slide rules were used by engineers well into the 1970s.

Blaise Pascal, a French mathematician, built the Pascaline at age 19 to help his father with tax calculations. It used a series of interlocking gears to add and subtract numbers. Gottfried Leibniz improved on Pascal's design with the Leibniz Wheel, a machine that could also multiply and divide. Leibniz also developed the binary number system that computers use today.

Charles Babbage and Ada Lovelace

Charles Babbage designed the Difference Engine in 1822 to calculate mathematical tables automatically. He later designed the Analytical Engine in 1837, which had a mill (like a CPU), a store (like memory), and could follow instructions on punched cards. It was never fully built in his lifetime, but it contained the core ideas of every modern computer, namely processing, memory, and programmability.

Ada Lovelace, working with Babbage, wrote detailed step-by-step instructions for the Analytical Engine to compute Bernoulli numbers. These instructions are widely regarded as the first computer program, and Ada is celebrated as the first computer programmer. Her insight was that the machine could manipulate symbols, not just numbers, making it a general-purpose computer.

The First Electronic Computers

ENIAC (Electronic Numerical Integrator and Computer) was built at the University of Pennsylvania by John Presper Eckert and John Mauchly. It was completed in 1945 and could perform 5,000 additions per second. ENIAC contained about 17,468 vacuum tubes, weighed 27 tons, and filled a large room. It was general-purpose, meaning it could be reprogrammed to solve different problems, though reprogramming took days of rewiring cables.

UNIVAC I (Universal Automatic Computer) was the first computer manufactured and sold commercially in the United States. It was designed by the same team and was used by the US Census Bureau. UNIVAC famously predicted the result of the 1952 presidential election on live television. UNIVAC introduced magnetic tape for data storage, replacing punched cards for many tasks and making data handling faster.

Vacuum tubes were glass bulbs that controlled electrical flow. They were large, fragile, consumed enormous amounts of power, and generated intense heat. ENIAC needed a dedicated air-conditioning system. These limitations motivated inventors to find a smaller, cooler, cheaper alternative.

Transistors, Integrated Circuits, and Modern Computing

The transistor was invented at Bell Laboratories in 1947 by John Bardeen, Walter Brattain, and William Shockley. A transistor performs the same switching function as a vacuum tube but is far smaller, uses less power, generates less heat, and lasts much longer. Computers built with transistors (second generation, roughly 1956 to 1963) were smaller, faster, and more reliable. Programming languages like FORTRAN and COBOL were developed during this era.

Jack Kilby (Texas Instruments) and Robert Noyce (Fairchild Semiconductor) independently developed the integrated circuit in 1958. An IC places many transistors, resistors, and capacitors on a single small chip of silicon. This eliminated the need to wire individual components together. Third-generation computers (1964 to 1971) used integrated circuits and introduced operating systems, allowing multiple programs to run at once. Computers became affordable enough for schools and small businesses.

In 1971, Intel released the 4004, the first microprocessor, placing an entire CPU on one chip. This made personal computers possible. The fourth generation (1971 to present) saw the rise of personal computers, mobile devices, and the internet. The fifth generation (present and future) involves artificial intelligence, cloud computing, and networked systems.

Modern computing extends far beyond the desktop. Smartphones, tablets, wearables, servers in data centres, and cloud platforms all rely on the same principles developed over centuries. In Nigeria, digital computing powers mobile banking (e.g., OPay, PalmPay), e-learning platforms, government portals, health record systems, and the entertainment industry.

Practical Work

1. Draw a timeline from the abacus to a modern computer.
2. Match each early device with its inventor and its use.
3. Write two differences between a mechanical and an electronic computer.
4. Name the component that replaced the vacuum tube.

Scenario-Based Questions

1. A shopkeeper in a market town needs to add and subtract large daily totals without electricity. Between the abacus and the Pascaline, recommend the tool better suited to the job and justify your choice using what you know about how each one works.
2. A museum wants to display the machine that first contained the core ideas of every modern computer. Explain why Babbage's Analytical Engine deserves the display, and name the parts that foreshadow today's processing and memory.
3. A student reads that Ada Lovelace wrote a program for a machine that was never built. Explain why she is regarded as the first programmer, and what her insight about symbols made the Analytical Engine a general purpose machine.
4. ENIAC filled a large room, weighed 27 tons, and used about 17,468 vacuum tubes, yet a modern laptop is far more powerful. Trace the changes from vacuum tubes to transistors to integrated circuits to microprocessors that made this small and fast machine possible.
5. In the 1950s a company must choose between keeping a room of vacuum tube machines and switching to transistor machines for the same work. Compare size, power use, heat, and reliability, and recommend one with reasons from your note.
6. A supplier tells a school that the Intel 4004 is the reason cheap personal computers exist today. Explain what the 4004 was, when it was released, and why putting an entire CPU on one chip changed the market.
7. Imagine integrated circuits had never been invented. Using the generation table in your note, predict what the size, cost, and daily use of computers would be like in a modern office, and justify your prediction.

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

Rationale: People invented tools for calculation long before electricity. Understanding early Calculating Devices, charles Babbage and Ada Lovelace, the First Electronic Computers, transistors, Integrated Circuits, and Modern Computing helps learners use digital technology confidently, safely and responsibly.

Pre-requisite Knowledge: In Week 1, learners studied Computer Systems and Digital Technologies, including what is a Computer System?, the Input-Process-Output (IPO) Model, role of the CPU. 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 History and Evolution of Computing, 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 2); First Term examination and Continuous Assessment question papers.

LESSON DEVELOPMENT

Assignment: i. A school wants to know why computers became smaller, cheaper and easier to use, and why personal computers became possible. Explain the invention of the transistor, the integrated circuit and the microprocessor, and name the generations of computing that followed. ii. A shopkeeper in a market town needs to add and subtract large daily totals without electricity. Between the abacus and the Pascaline, recommend the tool better suited to the job and justify your choice using what you know about how each one works.