In fact, the computer keyboard art has descended from the visual art that started in 1867 as a recreational activity by the typists using manual typewriters during their free time. Now, since many people spend a lot of time on computers, the keyboard art is taking shape as a recognised visual art.
One of the main reasons ASCII art was born was because early printers often lacked graphics ability and thus characters were used in place of graphic marks. Also, bulk printers often used ASCII art to print large banners. But the trend got coverted into a recognised keyboard visual art and computer users taking to it.
In the first half of 1980s, the limitations of computers of that time period necessitated the use of text characters to represent images. Along with ASCII's use in communication, however, it also began to appear in online art groups of that time. Even, ASCII web-comic which uses ASCII text to create images with the dialog usually placed underneath the keyboard visuals were also popular.
ASCII art can be created with any text editor these days. It is often used with free-form languages and a fixed-width font such as Courier for presentation. Different techniques could be used in ASCII art to obtain different artistic effects.
The keyboard line art can be used for creating shapes; keyboard Solid art can used for creating filled objects; and for shading one can use various symbols with different intensities for creating gradients or contrasts. Various combinations of the foregoing can be used to create keyboard art.
The inset visual art is a good example of a simple creations illustrated of keyboard artwork in wWikipedia using the computer keyboard. It depicts truchs, a bird and the face of a cat.