Tektronix 4014

The Tektronix 4014 was an early text and graphics computer terminal based on the company's own storage tube technology. The terminal was introduced by Tektronix around 1974.

Prior to the 4014, most computer graphics was done with vector graphics displays that continouosly repainted the image under computer control. This required a very high bandwidth connection to the computer, which generally meant the display could be no more than a dozen or so meters from the computer. The modern approach of having a local memory in the display that stores a value for each pixel would have been prohibitively expensive in the 1970s. Tektronix solved this problem by developing the Direct View Bistable Storage Tube (DVBST) CRT, which allowed the use of a slower, serial, data connection combined with a vector graphics generator that only needed to write the vectors (the graphic data) to the CRT once. Having had data written, the CRT itself remembered the data.

Individual portions of the image could not be erased, however. Instead, the entire stored image was erased as a whole and the process caused the entire screen to flash bright green. This led to the 4014 terminal being nicknamed the mean green flashin' machine.

For graphics input, the terminal used a pair of thumb wheels on the keyboard to control the position of a cursor. The cursor was displayed using a lower intensity of the electron beam that was insufficient to store the cursor's image. Instead, the cursor was dynamically refreshed by the electronics of the terminal.

The 4014 had a series of commands for drawing both text and graphics. The 4014 command set became a de facto standard and when personal computers with graphics displays became common in the 1990s, many communications packages included the ability to accept Tektronix 4014 commands. Because of this the designation "(Tektronix) 4014" has entered the traditional computing vocabulary, leading to the memory of the terminal long after the actual hardware became obsolete and otherwise disappeared.

The 4014 was not the first computer terminal to use Tektronix storage tubes. An earlier device was called ARDS for Advanced Remote Display Station and originated at MIT's Project MAC. In addition, Digital Equipment Corporation of Maynard, Massachusetts sold a graphics system called the KV8I (later, KV8E) that used a Tektronix 603 storage display as its output device with the KV8I generating the vectors.

External links

*Tektronix 4014 and 4014-1 Computer Display Terminal User's Manual