1. A modern computer is one which not only can store data and do calculations and other processing but also can store a program which provides instructions on what processing is to be done on the data. This concept was first developed in the mid 1930s.

2. The first modern computer was built in the 1940s during the Second World War. However, since this development was secret (it was used to help with code breaking), early computer histories did not include this development.

3. In the 1950s, other computers were devdeloped by universities and governments. These typically used vacuum tubes for the storage of data and processing. As a result these computers were very large, often filling a room; stored only relatively small amounts of data; and had very slow processing. They were also very expensive to build.

4. In the late 1950s the transistor was developed. These replaced vacuum tubes so made it possible to make smaller, less expensive and more efficient computers.

5. In the 1960s, more powerful computers were developed which included such things as magnetic tapes or disks for data storage. These were now inexpensive enough to be affordable by large companies or schools. Such companies as IBM (International Business Machines) grew and the use of computers became more common.

6. In late 1960s and early 1970s the microchip was developed with could include thousands of transistors within one small package (the chip). Microchips were developed which included memory as well as processing facilities. These became microprocessors. These are now the basis for the modern computers used today including desktop computers, laptop computers, notebook computers, tables, and smart phones.

7. Various companies developed personal computers (PCs) during the 1970s including Apple (the Apple and Apple 2 computers) and the Tandy Corporation the Radio Shack TRS-80).

8. In 1981 IBM started selling the IBM PC. It became the standard for personal computers with competition from Apple Corporation. Rather than develop it own operating system for the PC, IBM used the Disk Operating System (DOS) developed by Microsoft. It was called PC-DOS. However, Microsoft kept the ownership of DOS and eventually started selling it separately to other computer manufacturers as MS-DOS (Microsoft DOS). The PC, originally sold by IBM and then eventually by other manufacturers, become a standard for personal computing.

9. In 1984 the Apple company introduced its MacIntosh computer to rival IBMs PCs. Eventually they developed a "Windows" type operating system for the McIntosh which made its use more intuitive. One could use a mouse to point to objects or text on the screen to select them or process them. This was so popular that Microsoft developed its Windows operating system.

To be continued............