Blitter

A blitter, short for block transfer, is a specialized hardware component found in some video game consoles and computers. Its primary function is to accelerate the copying of blocks of data, typically graphics information, from one memory location to another. This process is crucial for efficiently rendering graphics on screen, especially for tasks like moving sprites, drawing backgrounds, or clearing areas of the screen.

The blitter operates independently of the main CPU, allowing the CPU to perform other tasks while the blitter handles the data transfer. This offloading of graphical operations significantly improves overall system performance, leading to smoother animation and more complex visual effects. Blitters often include additional features beyond simple copying, such as the ability to perform logical operations (AND, OR, XOR) between the source and destination data, allowing for effects like transparency and color manipulation.

Early examples of blitters appeared in arcade machines and home computers of the 1980s. For instance, the Amiga personal computer famously featured a powerful custom blitter chip that was a key component of its graphical capabilities. Similarly, consoles like the Sega Genesis and Super Nintendo Entertainment System incorporated blitter-like functionality to achieve their distinctive visual styles. While modern GPUs have largely superseded the role of dedicated blitter chips in computers and consoles, the fundamental concept of hardware-accelerated block transfer remains a cornerstone of graphical processing.