The NCR System 3125 is a sophisticated tablet, or pen-based portable computer. That is it does not use a keyboard or mouse for the input and retrieval of data. All the computer's programs are accessed by the use of a 'pen' - a stylus that is designed to interact with the surface of the screen and either input text which is read by the computer and interpreted as commands, or activate virtual buttons on the screen to open, access, save, edit and close programs.
Though this technology was not new in 1991, the NCR System 3125 was a much more powerful computer than other tablets on the market at the time. Its main competitor, the Grid System's Gridpad was inexpensive in comparison, but was not as sophisticated. Whereas the Gridpad was designed for field workers who needed to enter information into electronic pro-formas, the System 3125 could power programs that were up until then only available on desk-top systems - such as spread-sheets and graphs.
At the time the that System 3125 was released on to the market, tablet computers were still something of a specialist tool. They were expensive, or they were quite limited in their computing power. The mainstream computer market did not catch onto the concept in any significant way. Other companies also developed notebook computers - Sharp and Apple chief among them - but they too did not have any large success. The popularity and accelerated advance in technology of the mobile telephone in recent years has changed the way people use mobile technology, and thus the concept of the tablet computer has become widely accepted. Apple's latest tablet computer - the iPad - has quickly become a standard piece of personal electronic equipment for both professional and leisure use. The concept though is not new.