About Dates Used in this Encyclopedia

Some of the dates used in this encyclopedia are estimates. The reason for this is the difficulty that sometimes occurs when researching the introduction of a new computer technology into the marketplace. Due to the lengthy time involved in the development stages of early computers, and due to the timing chosen by companies as to when it was advantageous to announce them to the public, there can be a variety of different dates that can be found in early reference materials. Here are some examples.

- The date the machine was first under development. This can be the conceptual stage up to the actual build stage.

- The date the machine becomes first operational. This is usually important on early experimental machines or machines incorporating new technologies.

- The date the machine was announced to the public. This can be during the development stage or after the development stage, depending on when the company decides to make its formal announcement.

- The date the machine was formally dedicated. This is usually after formal development and testing is done, and the machine is ready for market.

- The date the machine is first available on the market.

- The date when the machine first ships from the manufacturer.

- The date when the machine is first installed at a customer site.


In this encyclopedia, we tended to use the earliest date the machine was operational, unless otherwise noted in the text. You may find other sources that do not match every date listed here, depending on what sources were used. Most dates are correct to within a year or so.

Use your browser's Back button to return to previous screen.