Third generation of computers, Integrated circuits, 1964-1971

Third generation of computers, Integrated Circuits, 1964-1971. The third generation of computers refers to a period in the history of computing that took place roughly between the mid-1960s and the mid-1970s. During this period, significant advances in computer technology occurred, resulting in more powerful and capable machines compared to previous generations of computers.

Integrated circuits

The integrated circuit (IC) concept was first proposed by Geoffrey W.A. Dummer, a British engineer, in 1952. Dummer’s idea was to integrate multiple electronic components, such as transistors, resistors, and capacitors, into a single piece of semiconductor material, thus creating a complete electronic circuit. However, Dummer’s proposal did not lead to the immediate development of functional integrated circuits.

The first successful integrated circuit was invented independently by two researchers, Jack Kilby of Texas Instruments and Robert Noyce of Fairchild Semiconductor, in the late 1950s. Kilby’s invention was a “monolithic” IC, which used germanium as a semiconductor material, and proved its functionality on September 12, 1958. Noyce’s invention, meanwhile, was a “planar” integrated circuit, which used silicon as a semiconductor material, and he patented it in July 1959.

Both Kilby’s and Noyce’s inventions were a breakthrough in the field of electronics, paving the way for the development of smaller, more reliable and more powerful electronic devices. The invention of integrated circuits revolutionized the field of electronics and laid the foundation for the rapid advancement of computer technology and other electronic devices, such as smartphones, tablets, and microcontrollers, that we use today.

After the invention of integrated circuits, their development and commercialization progressed rapidly, and several companies and researchers further refined the technology and made it more accessible and affordable. Today, integrated circuits are used in a wide range of applications, from computers and telecommunications to consumer electronics, automotive systems, and medical devices, among others. They have transformed the world of electronics and become an indispensable part of modern technology.

Features of the third generation of computers

Here are some of the key features of the third generation of computers:

  • Integrated circuits (ICs): The most significant advance of the third generation was the development and widespread use of integrated circuits (ICs). These miniature electronics enabled the integration of multiple transistors, resistors and capacitors into a single semiconductor material chip, significantly reducing the size, cost and power consumption of computers.
  • Transistors: Transistors, which had replaced vacuum tubes in the second generation, became even smaller and more reliable in the third. This resulted in more efficient and reliable computers, with greater processing power.
  • High-level programming languages: During the third generation, high-level programming languages such as COBOL, FORTRAN and BASIC were developed. These languages facilitated programming and made it more accessible to a greater number of users, allowing the development of more sophisticated software applications.
  • Time-sharing and multiprogramming: Time-sharing and multiprogramming became more prevalent during the third generation. Timesharing allowed multiple users to simultaneously access a computer system, while multiprogramming allowed multiple programs to be run at once, taking better advantage of the computer’s processing power.
  • Magnetic disk storage: Storage on magnetic disks, such as hard disk drives, became widespread during the third generation. This enabled larger storage capacities, faster data access times, and more efficient data management.
  • The third generation witnessed the commercialization of computers, with the emergence of companies such as IBM, DEC and Burroughs, which produced and sold computer systems for business and scientific applications.
  • Minicomputers: Minicomputers, smaller and less expensive than mainframe computers, became popular during the third generation. They were used for various applications, such as scientific research, enterprise data processing, and industrial control systems.
  • The third generation of computers represented a significant advance in computer technology, with smaller, faster and more powerful machines, more accessible to a greater number of users. These advances paved the way for other developments in later generations, giving rise to the modern computing landscape we have today.


COBOL, FORTRAN and BASIC are high-level programming languages that were developed during the early years of computer science and have played an important role in the history of computer programming.

COBOL (Common Business Oriented Language)

COBOL was developed in the late 1950s and early 1960s by a committee of computer professionals from government, academia, and industry, led by Grace Hopper. COBOL was designed specifically for enterprise applications and was intended to be a language that business users could easily understand and use to develop software for enterprise data processing. COBOL was one of the first programming languages to gain widespread adoption and was widely used in the early days of computing for business and administrative applications.

FORTRAN (FORmula TRANslation)

It was the first high-level programming language and was designed to be used in mathematical and scientific calculations, making it easier to write complex mathematical algorithms for scientific research and engineering applications. FORTRAN quickly gained popularity in the scientific community and became the dominant programming language for scientific and engineering calculations during the early years of computer science.

BASIC (Beginners’ All-purpose Symbolic Instruction Code)

BASIC was developed in the mid-60s by John Kemeny and Thomas Kurtz at Dartmouth College as an easy-to-learn programming language for students and beginners. BASIC was designed as a simple language that could be used to teach computer programming to non-technical users and was widely used in educational institutions and personal computers during the early days of computer science. BASIC played an important role in making computer programming more accessible to a wider audience and is still used in some form today.

These three programming languages, COBOL, FORTRAN and BASIC, were among the first high-level programming languages and played an important role in the early development of computer programming. They paved the way for the development of more sophisticated programming languages and have left a lasting impact on the field of computer programming, with some variants of these languages still being used in certain domains and industries today.


The origin of minicomputers dates back to the 1960s and 1970s, when advances in computer technology allowed for the development of smaller, more affordable and less powerful computers than mainframes, which were large and expensive.

The term “minicomputer” was first coined by Digital Equipment Corporation (DEC), a pioneering computer manufacturer founded by Ken Olsen in 1957. DEC introduced the PDP-1 (Programmed Data Processor-1) in 1959, considered one of the first minicomputers. The PDP-1 was relatively small, the size of a refrigerator, and was designed for scientific and engineering calculations.

The success of the PDP-1 led to the development of other minicomputers by DEC and other companies such as IBM, Hewlett-Packard (HP) and Data General. These minicomputers were smaller and less powerful than mainframe computers, but they were more affordable and accessible to smaller organizations, universities, research labs, and companies that needed computing power for specific tasks.

Minicomputers were characterized by their relatively small size, cost-effectiveness, and versatility. They were often used for scientific research, process control, data analysis, and business applications. Minicomputers were also known for their interactive computing capabilities, which allowed users to interact with the computer in real time through terminals or screens.

The evolution of minicomputers continued over the years, with improvements in processor technology, memory capacity, storage, and networking capabilities. However, with the advent of microcomputers or personal computers in the 1980s, which were even smaller, more affordable and had greater computing power, the demand for minicomputers decreased, and they gradually disappeared from the market. Today, the concept of minicomputer is largely obsolete, as modern computers, including laptops, tablets, and smartphones, have become smaller, more powerful, and widely accessible to individuals and organizations of all sizes.

1965 SDS 92

The SDS 92 was a minicomputer introduced in 1965 by Scientific Data Systems (SDS), a pioneering computer manufacturer founded by Max Palevsky and others. The SDS 92 was one of the first minicomputers and was known for its innovative design and advanced features for its time.

The SDS 92 was a 24-bit computer that used magnetic core memory for its primary storage, which was a common type of memory technology used in early computers. It had a relatively fast clock speed of 1.5 MHz at the time, and used a transistor-based design, which was a significant advance over early vacuum-tube computers in terms of size, power consumption, and reliability.

One of the notable features of the SDS 92 was its instruction set architecture (ISA), designed to be very versatile and efficient. The SDS 92’s ISA included a unique feature called “extended addressing,” which allowed it to access up to 4 megabytes (4 million bytes) of memory, an impressive amount for the time. This made the SDS 92 suitable for a wide range of applications, such as scientific computing, data processing, and real-time control.

The SDS 92 also stood out for its operating system called “SDS 940”, which offered a complete set of tools and software utilities to program and manage the computer. The operating system had a time-sharing system that allowed several users to share computer resources simultaneously, making it ideal for interactive computing.

The SDS 92 was used in various applications, such as scientific research, engineering and business computing. However, SDS faced financial problems in the late 1960s and was eventually acquired by Xerox Corporation in 1969, so production of SDS computers, including the SDS 92, ceased in the early 1970s. However, SDS 92 played an important role in the early history of minicomputers and contributed to the advancement of computer technology during that time.

Hewlett-Packard 21xx

The Hewlett-Packard (HP) 21xx series was a family of small minicomputers introduced by HP in the late sixties and early seventies. The HP 21xx series was known for its compact design, reliability, and versatility, and was widely used in various applications, such as scientific research, process control, and data acquisition.

The HP 21xx series had a 16-bit architecture and used semiconductor memory, a relatively advanced technology for the time. The series included several models with different processing capacities, memory sizes and input/output options, allowing users to choose the system that best suited their needs.

One of the outstanding features of the HP 21xx series was its instruction set architecture (ISA), designed to be simple and efficient. The ISA included an extensive set of instructions that supported a wide variety of data manipulation, logic operations, and control flow, making it suitable for a wide variety of computing tasks.

The HP 21xx series also featured a unique hardware feature called the “I/O channel,” which allowed the system to interact with a variety of peripherals and devices, such as printers, terminals, and data storage devices. This made the HP 21xx series versatile and capable of interacting with a wide range of external devices.

The HP 21xx series was known for its reliability and durability, and was widely used in industrial and scientific environments where robustness and stability were important factors. The systems were also known for their ease of use and maintenance, with features such as diagnostic tools and a modular design that made maintenance and upgrade relatively straightforward.

Over time, the HP 21xx series was replaced by new HP minicomputer models, such as the HP 1000 series, which continued to be used in various applications throughout the 1970s and beyond. The HP 21xx series played an important role in the history of minicomputers and contributed to HP’s reputation as a leading computer manufacturer in the early days of computing.

IBM System/360

The IBM System/360 (IBM-360) was a family of mainframe computers introduced by IBM in 1964. It was a revolutionary computer system that set a new standard for large-scale computing and had a profound impact on the field of computer science.

The IBM-360 stood out for its modular and compatible design, which allowed users to choose from a wide range of models with different processing capabilities, memory sizes and input/output options, depending on their needs. This flexibility made the IBM-360 suitable for a wide range of applications, from scientific and engineering computing to enterprise data processing.

One of the main innovations of the IBM-360 was the use of microcode, a layer of low-level software that allowed emulating the computer’s instruction set in hardware. As a result, the IBM-360 was highly versatile and extensible, allowing it to support a wide variety of programming languages, operating systems, and applications.

The IBM-360 also introduced virtual memory, a revolutionary concept that allowed multiple programs to run simultaneously in separate virtual address spaces, even if physical memory was limited. This greatly improved system efficiency and resource utilization, and paved the way for modern operating systems and virtualization technologies.

Another notable feature of the IBM-360 was its backward compatibility, which allowed users to run programs developed for earlier IBM mainframes, preserving their software investments. This ensured a smooth transition for IBM customers who had already developed applications for previous IBM mainframes.

The IBM-360 was widely adopted by companies, public bodies, and research institutions around the world, and became the dominant mainframe computing platform in the 1960s and 1970s. Its success cemented IBM as a leading computer manufacturer and helped shape the modern computing landscape.

The IBM-360 was followed by later generations of IBM mainframes, such as the System/370, System/390 and current IBM Z systems, which continue to be used in large-scale computing environments for critical business and infrastructure applications. The IBM-360 remains an important milestone in the history of computing, and its impact can still be seen in many aspects of modern computer technology.

Read also: Fifth generation of computers, 1980 onwards, features; What are the 5 generations of computers or computer technology?; What is fragmentation in computing? Video

External resource: Geeksforgeeks

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