A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's cathode-ray tube (CRT) display. It allows the user to point to displayed objects or draw on the screen in a similar way to a touchscreen but with greater positional accuracy.

Oct 18, 2023 · A light pen is a type of pointing input device that detects light and is frequently used to select or alter text or data on a screen. These devices, when used with a CRT (cathode ray tube) monitor, were an early method of highlighting and modifying data on the screen.

How a light pen works. Unlike modern flat TV’s, old school Cathode Ray Tubes (CRT’s) draw the image line by line onto their phosphorescent screen. A photo transistor, placed on a tube TV’s surface, can recognize when the part of the image is drawn underneath it.

Nov 11, 2009 · The light pen thing happened to come along with the 6845 CRTC on the original adapters. Unless the chipset for your VGA happens to have provision for light pen input, it's going to be pretty difficult knowing exactly where the spot is on the CRT screen.

Dec 7, 2018 · A routine use of a light pen I've observed not on a PDP, though, but on a MIR-2 computer. For text editing with a CRT display and an electric typewriter, the light pen was used pretty much the same way the mouse is used today to …

A light pen is a special kind of pointer used with cathode ray tube (CRT) displays. Using the light pen an operator can select, draw, or modify pictures on the CRT by means similar to

A light pen is used as a receptor to scan different pixels of light sensitivity on the screen with the help of the CRT tube elements. An electronic device is connected with the light pen to draw the image of the object scanned from the CPU.

Oct 11, 2017 · A light pen is a light-sensitive pointing input device commonly used to select or otherwise modify text or data on a screen. Used with a CRT (Cathode Ray Tube) monitor, these devices were an early form of manipulating and highlighting data on the screen.

A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's cathode-ray tube (CRT) display.

Jun 12, 2022 · If you worked with computers back in the 1970s, there’s a good chance you used a light pen at some point: a simple input device that you’d point at the CRT screen to highlight text, choose menu...