Difference between revisions of "Video terminal"

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A '''video terminal''' was a device used to allow a [[user]] to do [[input/output]] to a computer; it usually communicated with the computer via [[asynchronous serial line]]. It was effectively roughly the same as the earlier [[printing terminal]]s such as [[Teletype]]s, but with characters being 'painted' on a [[cathode ray tube|CRT]] via a purely [[electronic]] process, instead of being printed on paper by a mechanical system.
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A '''video terminal''' was a [[terminal]] on which the characters being output were 'painted' on a [[cathode ray tube|CRT]] via a purely [[electronic]] process. It was thus roughly the same functionality as the earlier [[printing terminal]]s, such as [[Teletype]]s, but instead of the output being printed on paper by a mechanical system, it was displayed on the screen. Like the earlier printing terminals, they were used to allow a [[user]] to do [[input/output]] to a computer; they usually communicated with the computer via [[asynchronous serial line]].  
  
The original chief advantage was speed, since the all-electronic mechanism could run at much higher speeds; the disadvantage was that only a limited amount of information could be displayed at one time. (This was particularly true as early ones could only display very limited amounts of text - some as small as 12 lines of 40 characters).
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The original chief advantage was speed, since the all-electronic mechanism could run at much higher speeds; the disadvantage was that only a limited amount of information could be displayed at one time. (This was particularly true of early ones, which could only display very limited amounts of text - some as small as 12 lines of 40 characters).
  
 
Very early model provided only the same motion controls as their printing predecessors - line feed, carriage return, etc. However, the ability to move the [[cursor]] to specific screen locations was soon added, which made possible a predecessor of [[WYSIWYG]], to wit, [[screen editor]]s such as [[Emacs editors|EMACS]].
 
Very early model provided only the same motion controls as their printing predecessors - line feed, carriage return, etc. However, the ability to move the [[cursor]] to specific screen locations was soon added, which made possible a predecessor of [[WYSIWYG]], to wit, [[screen editor]]s such as [[Emacs editors|EMACS]].
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==See also==
 
==See also==
  
* [[:Category:Video Terminals]]
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* [[:Category:Video Terminals|Video Terminals]]
  
 
[[Category: Device Basics‎‎]]
 
[[Category: Device Basics‎‎]]

Latest revision as of 02:27, 7 May 2021

A video terminal was a terminal on which the characters being output were 'painted' on a CRT via a purely electronic process. It was thus roughly the same functionality as the earlier printing terminals, such as Teletypes, but instead of the output being printed on paper by a mechanical system, it was displayed on the screen. Like the earlier printing terminals, they were used to allow a user to do input/output to a computer; they usually communicated with the computer via asynchronous serial line.

The original chief advantage was speed, since the all-electronic mechanism could run at much higher speeds; the disadvantage was that only a limited amount of information could be displayed at one time. (This was particularly true of early ones, which could only display very limited amounts of text - some as small as 12 lines of 40 characters).

Very early model provided only the same motion controls as their printing predecessors - line feed, carriage return, etc. However, the ability to move the cursor to specific screen locations was soon added, which made possible a predecessor of WYSIWYG, to wit, screen editors such as EMACS.

A few had the capability to do graphics, such as lines, points, etc.

Once semiconductor RAM prices fell low enough, they were replaced with bit-mapped display‏‎s, although the latter were directly connected to the computer's main bus, usually on a personal computer.

See also