Features of 2nd Generation Computers

What Are Second Generation Computers?

Second generation computers represent the next major step in computer evolution after first generation machines. While first generation computers (1940-1956) used large vacuum tubes, second generation computers (1956-1963) used transistors—small electronic devices invented at Bell Laboratories in 1947.

This change from vacuum tubes to transistors revolutionized computing. Imagine replacing the large fluorescent tubes in a classroom with tiny LED bulbs that give more light, use less electricity, and last longer. That’s similar to what transistors did for computers.

The transistor era made computers more practical for businesses, universities, and research institutions. For the first time, computers became reliable enough for daily commercial use rather than just scientific calculations.

Key Features and Characteristics of Second Generation Computers

1. Use of Transistors

The most important feature of second generation computers was the use of transistors to replace vacuum tubes. A transistor is a small semiconductor device that can amplify or switch electronic signals. Transistors were much smaller than vacuum tubes (about the size of a pencil eraser compared to a light bulb).

Transistors offered several advantages:

• Generated far less heat than vacuum tubes
• Required no warm-up time (vacuum tubes needed several minutes to heat up)
• More durable and reliable—lasted much longer
• Consumed less electrical power
• Allowed computers to be smaller in size
• Faster switching speed meant faster processing

A single second generation computer might contain thousands of transistors instead of thousands of vacuum tubes. This made them more affordable to operate because they needed less electricity and air conditioning.

2. Magnetic Core Memory

Second generation computers used magnetic core memory for primary storage. This was a major improvement over the magnetic drums used in first generation computers. Magnetic core memory consisted of tiny magnetic rings (cores) threaded on a grid of wires.

Each magnetic core could store one bit of information (either 0 or 1) based on the direction of its magnetic field. These cores were extremely reliable and could be accessed much faster than magnetic drums. A typical magnetic core memory module looked like a small woven mat with thousands of tiny rings.

The main advantages of magnetic core memory were:

• Faster access to data (measured in microseconds)
• Non-volatile storage (data remained even when power was turned off)
• More reliable than earlier storage methods
• Larger storage capacity than first generation computers

3. Magnetic Tape and Disk Storage

For secondary storage, second generation computers used magnetic tapes and magnetic disks. Magnetic tape worked like the cassette tapes used for music, storing data in sequential order. Magnetic disks (similar to modern hard drives but much larger) allowed faster access to stored data.

This was a significant improvement for businesses and organizations that needed to store large amounts of data, such as bank records, customer files, and inventory information.

4. Higher-Level Programming Languages

First generation computers used machine language (binary code) and assembly language, which were very difficult to learn and use. Second generation computers introduced high-level programming languages that were closer to human language and mathematics.

The most important programming languages developed during this period were:

• FORTRAN (1957): Formula Translation—designed for scientific and mathematical calculations
• COBOL (1959): Common Business Oriented Language—designed for business data processing
• ALGOL (1958): Algorithmic Language—used for scientific computing
• LISP (1958): List Processing—used for artificial intelligence research

These languages made programming much easier. Instead of writing complex binary codes, programmers could write instructions like “ADD SALARY TO TOTAL” in COBOL or “X = Y + Z” in FORTRAN.

5. Faster Processing Speed

Second generation computers were significantly faster than first generation machines. While first generation computers measured processing speed in milliseconds (thousandths of a second), second generation computers operated in microseconds (millionths of a second).

This meant calculations that took minutes on first generation computers could be completed in seconds on second generation machines. For example, complex mathematical problems, payroll processing for large companies, and scientific simulations became much more practical.

6. Smaller Physical Size

Because transistors were much smaller than vacuum tubes, second generation computers were considerably smaller than their predecessors. However, they were still quite large by today’s standards. A typical second generation computer still occupied an entire room, but it was perhaps one-third the size of a comparable first generation machine.

This reduction in size meant lower costs for housing the computers and easier installation in business and university settings.

7. More Reliable and Less Maintenance

Transistors were far more reliable than vacuum tubes. First generation computers using vacuum tubes broke down frequently—vacuum tubes would burn out regularly, requiring constant replacement. A large first generation computer might have tube failures several times per day.

Second generation computers with transistors could run for weeks or months without component failures. This reliability made them practical for business use where consistent operation was essential. Less downtime meant more productive work and lower maintenance costs.

8. Lower Power Consumption and Heat Generation

First generation computers consumed enormous amounts of electricity and generated tremendous heat. They required powerful air conditioning systems to prevent overheating. Some large first generation computers used as much electricity as a small factory.

Second generation computers used much less power—perhaps one-tenth of what first generation machines required. They also generated far less heat, reducing the need for expensive cooling systems. This made them cheaper to operate on a daily basis.

9. Batch Processing and Multiprogramming

Second generation computers introduced batch processing systems. In batch processing, similar jobs were grouped together and processed in batches rather than one at a time. For example, all payroll calculations for a company would be run together, then all inventory updates, and so on.

Some advanced second generation systems also introduced early forms of multiprogramming, where the computer could work on multiple programs in memory, switching between them to make efficient use of processor time. This was the beginning of the multitasking systems we use today.

10. Commercial Availability

Unlike first generation computers (which were mostly custom-built for specific organizations), second generation computers were manufactured and sold commercially. Companies like IBM, UNIVAC, Honeywell, and Burroughs produced computers that businesses could purchase.

This commercial availability meant more organizations could afford computers. Banks like Standard Bank and First Bank in Nigeria, large businesses, universities, and government agencies began installing computers for data processing tasks.

Examples of Second Generation Computers

• IBM 1401 (1959): One of the most popular business computers. Thousands were installed worldwide for accounting, billing, and inventory management
• IBM 7090 (1959): A powerful scientific computer used for complex calculations in research and engineering
• IBM 1620 (1959): A smaller, less expensive computer used in universities and research labs
• UNIVAC 1108 (1964): A powerful mainframe used by government and large corporations
• CDC 1604 (1960): Control Data Corporation’s entry into scientific computing
• Honeywell 400 (1960): A business data processing computer
• RCA 501 (1958): Designed for business applications
• IBM 7094 (1962): An advanced scientific computer used by NASA and military organizations

Applications of Second Generation Computers

Second generation computers found use in many fields:

• Business: Payroll processing, inventory management, billing, accounting
• Banking: Account management, check processing, interest calculations
• Airlines: Reservation systems (American Airlines’ SABRE system)
• Government: Census data processing, tax records, defense calculations
• Universities: Research, student records, scientific calculations
• Manufacturing: Production scheduling, quality control, inventory tracking
• Science: Weather prediction, nuclear research, space exploration

Comparison with Other Computer Generations

Advantages of Second Generation Computers

• Smaller in size compared to first generation computers
• More reliable with fewer breakdowns
• Faster processing speed (from milliseconds to microseconds)
• Less heat generation, requiring less air conditioning
• Lower power consumption, reducing operating costs
• Easier to program using high-level languages
• Larger storage capacity with magnetic core memory
• More commercially available and affordable
• Better suited for business applications
• Could run continuously for longer periods

Limitations of Second Generation Computers

• Still required special air-conditioned rooms
• Still very expensive (costing hundreds of thousands of dollars)
• Required specialized training to operate and maintain
• Batch processing meant slow turnaround for results
• Large physical size compared to later generations
• Limited multitasking capabilities
• Input/output operations were still relatively slow
• Magnetic core memory was expensive to produce

Common Exam Mistakes to Avoid

WAEC and NECO examiners report these common errors when students answer questions about second generation computers:

• Confusing vacuum tubes with transistors: Some students write that second generation computers used vacuum tubes. Remember: first generation = vacuum tubes, second generation = transistors
• Wrong time period: Writing that second generation lasted until 1970s. The correct period is 1956-1963
• Incomplete explanations: Just writing “they used transistors” without explaining why transistors were an improvement
• Mixing up programming languages: Listing languages from later generations or wrong decades
• Wrong examples: Naming modern computers or first generation computers as examples
• Not comparing with first generation: When asked to “explain features,” students forget to show how second generation improved on first generation
• Confusing memory types: Mixing up magnetic drums (first gen) with magnetic cores (second gen)
• Poor technical terms: Writing “magnetic cords” instead of “magnetic cores” or “transisters” instead of “transistors”

Practice Questions

Multiple Choice Questions

1. The main electronic component used in second generation computers was:
(a) Vacuum tubes
(b) Transistors ✓
(c) Integrated circuits
(d) Microprocessors

2. Which of the following programming languages was introduced during the second generation of computers?
(a) Machine language
(b) C++
(c) COBOL ✓
(d) Python

3. The period of second generation computers is approximately:
(a) 1940-1956
(b) 1956-1963 ✓
(c) 1964-1971
(d) 1971-1980

4. Second generation computers used which type of memory for primary storage?
(a) Magnetic drum
(b) Magnetic core ✓
(c) Semiconductor
(d) Optical storage

5. Which of these is an example of a second generation computer?
(a) ENIAC
(b) IBM 1401 ✓
(c) IBM 360
(d) Apple Macintosh

Essay Questions

1. (a) State the period covered by second generation computers (1 mark)
(b) Explain five features of second generation computers (10 marks)
(c) Give two examples of second generation computers (2 marks)

Exam tip: When explaining features, mention both what the feature was and why it was an improvement. For example, don’t just say “they used transistors”—explain that transistors were smaller, faster, more reliable, and consumed less power than vacuum tubes.

2. (a) Distinguish between first generation and second generation computers based on the following: (i) Electronic component used (ii) Speed (iii) Programming language (iv) Size (8 marks)
(b) State four advantages of second generation computers over first generation computers (4 marks)

Exam tip: “Distinguish” means to show clear differences between two things. Use comparative language like “while first generation used…, second generation used…” or create a two-column comparison.

3. (a) What is a transistor? (2 marks)
(b) Explain how the use of transistors improved second generation computers compared to first generation computers (6 marks)
(c) Describe the type of memory used in second generation computers (4 marks)

Exam tip: When asked to “describe,” provide details about how something looks, works, or is structured. For magnetic core memory, explain what it consisted of and how it functioned.

4. (a) List four examples of programming languages developed during the second generation of computers (4 marks)
(b) Explain why these high-level programming languages were an improvement over machine language (6 marks)

Exam tip: Connect your explanation to practical benefits. Show how high-level languages made programming faster, easier to learn, less error-prone, and more readable.

Memory Aids

To remember the main technology of each generation: “VTI-M”

• 1st generation: Vacuum Tubes
• 2nd generation: Transistors
• 3rd generation: Integrated Circuits
• 4th generation: Microprocessors

To remember second generation period: “56 to 63” (sounds like “fifty-six to sixty-three”)

To remember key languages: “FC-AL”

• FORTRAN (for science and math)
• COBOL (for business)
• ALGOL (for algorithms)
• LISP (for artificial intelligence)

To remember transistor advantages: “Small Feat Reduces Heat”

• Smaller size
• Feaster speed
• Reduced power consumption
• Heat generation much lower

To remember memory progression: “Drums → Cores → Chips” (1st gen → 2nd gen → 3rd gen)

Related Topics

• Generations of Computers (overview of all five generations)
• Features of 1st Generation Computers (to understand what came before)
• Features of 3rd Generation Computers (to see the next evolution)
• Features of 4th Generation Computers (modern personal computers)
• Features of 5th Generation Computers (current and future technology)
• Classification of Computers (understanding different classification systems)