Computer monitor

Lore & Background

Early electronic computer front panels used arrays of light bulbs to indicate register bit states, and this panel became known as the 'monitor'. As early monitors displayed very limited information, a line printer was the primary output device. Computer monitors were formerly called visual display units (VDUs), a term that mostly fell out of use by the 1990s.

The first computer monitors used cathode ray tubes (CRTs). Before home computers, video display terminals (VDTs) were often integrated with a keyboard in a single chassis, emulating a paper teletypewriter and earning the epithet 'glass TTY'. These displays were monochromatic and low-resolution. High-resolution CRT displays existed for specialized applications but were costly until the Tektronix 4010 terminal in 1972. Early home computers like the TRS-80 and Commodore PET used monochrome CRTs, while color capability appeared in machines such as the Apple II and Atari 2600. IBM introduced the Color Graphics Adapter in 1981 and the Enhanced Graphics Adapter in 1984. By the end of the 1980s, color progressive scan CRT monitors were widely available. CRTs remained dominant into the new millennium partly due to lower production costs.

Liquid-crystal displays (LCDs) were primarily used in laptops during the 1990s, where lower power consumption and lighter weight justified higher prices. The first standalone LCD monitors appeared in the mid-1990s. By 1997 they competed with CRTs, and in 2003 LCDs outsold CRTs for the first time. TFT-LCD became the dominant technology. OLED monitors provide benefits of both LCD and CRT but suffer from burn-in and are comparatively more expensive.

Reader's Guide

The computer monitor evolved from a simple array of lights for monitoring internal machine states to a primary output device capable of displaying both data and video. Its history reflects the shift from CRT to LCD technology, driven by demands for lighter, smaller, and more power-efficient displays. The transition from 4:3 to 16:9 aspect ratios after 2010 aligned monitors with television standards, making them functionally interchangeable with TV sets, though most monitors lack integrated speakers, TV tuners, or remote controls. Performance measurements such as viewable image size, aspect ratio, display resolution, and dot pitch became standardized as the technology matured. The monitor's role expanded from data processing to encompassing video, gaming, and professional graphics, with specialized fields like vision science still relying on CRTs for their temporal accuracy. The adoption of HDR in high-end LCD monitors improved grayscale accuracy, while OLEDs offered further advantages at a higher cost. The monitor's legacy is one of continuous adaptation, from the glass TTY to the high-resolution, widescreen displays that now serve as the primary visual interface for computing.

Did You Know?

• Early computer monitors were called 'visual display units' (VDUs), a term mostly abandoned by the 1990s.
• The first standalone LCD computer monitors appeared in the mid-1990s.
• CRT monitors can use arbitrary lower resolutions without aliasing, unlike LCDs.