Tektronix 4010

4014 redirects here. For the Union Pacific Railway locomotive currently being restored, please see Union Pacific 4014

A Tektronix 4014 computer terminal.

The Tektronix 401x series was a family of text and graphics computer terminals based on the company's storage tube technology. The 4000 series were less expensive (under $10 000^[1]) than earlier graphics terminals, such as the IBM 2250 because no additional electronics were needed to maintain the display on the screen (beyond providing proper voltages to it). They were widely used in the CAD market in the 1970s and early 1980s. There were several members of the family introduced through the 1970s, the best known being the 4010 and 4014. They remained popular until the introduction of inexpensive graphics workstations in the 1980s. The new graphics workstations used raster displays and dedicated screen buffers that became more affordable as solid state memory chips became cheaper.

Features

Graphics display

Prior to the 4010, released in 1972,^[2] most computer graphics was done with vector graphics displays that continuously 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. New content could be added to the displayed image, but individual portions of the image could not be erased. Instead, the entire displayed image had to be erased, a process that caused the entire screen to flash bright green. The revised image would then be repainted from scratch.

Graphics input

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.

Commands

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.

History

The Tektronix direct-view storage tube was first used in the Tektronix 564 oscilloscope in 1963 and was first used for non-oscilloscope applications in the 601 monitor in 1968.^[3] Another early 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.

The first Tektronix computer terminal to use a storage tube was the T4002 Terminal, and the first member of the 4010 Series was the 4010, introduced around 1972. Other models included the 4012 (added lower case to the 4010 hardware character set), 4014 (four times the 4010 screen area), 4105, and 4016-1. Several peripherals were available, including the 4631 Hard Copy Unit, which produced screenshots on dry silver paper that were then heat-developed in the printer.

xterm still emulates the 4014 (xterm -t), as well as the VT220.

4010 Technical data

To make it work as a RS-232C at 2400 bit/s, no-parity, 8-bits, 1 stop-bit. Set the T Data strap to Normal. R Data strap to Invert. Baud Shift to On, and adjusted the trimmer by TP1 to give a clock frequency of about 19 kHz, measured at TP1.^[4]

References

External links

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