640x400

640x400 is a video display resolution with a width of 640 pixels and a height of 400 pixels, resulting in a total of 256,000 pixels. This resolution was commonly used in early personal computers and video games during the 1980s and 1990s. It is often referred to as "VGA" (Video Graphics Array) resolution, although VGA is a broader term that encompasses various resolutions.

The 640x400 resolution was popular due to its compatibility with the CGA (Color Graphics Adapter) and EGA (Enhanced Graphics Adapter) graphics standards, which were widely used in early IBM PC compatibles. It offered a balance between detail and performance, allowing for simple graphics and text displays.

In the context of video games, 640x400 provided a decent level of detail for the time, supporting various gameplay elements such as sprites, backgrounds, and simple animations. Many classic games were designed with this resolution in mind, ensuring compatibility with a wide range of hardware.

The 640x400 resolution also played a significant role in the development of early graphical user interfaces (GUIs), with operating systems like MS-DOS and early versions of Windows using this resolution for their displays.

Today, 640x400 is largely considered obsolete, with higher resolutions like 1024x768, 1280x720, and beyond being the standard in modern computing and gaming. However, it remains an important part of computing history, showcasing the evolution of display technology and its impact on the development of software and hardware.