Editing Blitter (section)

{{Short description|Integrated circuit for rapid data synchronization}}
{{Refimprove|date=January 2008}}

A '''blitter'''  is a circuit, sometimes as a [[coprocessor]] or a [[logic block]] on a [[microprocessor]], dedicated to the rapid movement and modification of data within a computer's [[Random-access memory|memory]]. A blitter can copy large quantities of data from one memory area to another relatively quickly, and in parallel with the [[Central processing unit|CPU]], while freeing up the CPU's more complex capabilities for other operations. A typical use for a blitter is the movement of a [[bitmap]], such as windows and icons in a [[graphical user interface]] or images and backgrounds in a 2D video game. The name comes from the  [[bit blit]] operation of the 1973 [[Xerox Alto]],<ref name="shirriff"/> which stands for bit-block transfer.<ref>{{cite web|url=https://msdn.microsoft.com/en-us/library/windows/desktop/dd183370(v=vs.85).aspx|title=BitBlt function|website=Windows Dev Network|publisher=Microsoft|access-date=2 October 2016}}</ref> A blit operation is more than a memory copy, because it can involve data that's not byte aligned (hence the ''bit'' in ''bit blit''), handling transparent pixels (pixels which should not overwrite the destination), and various ways of combining the source and destination data.

Blitters have largely been superseded by programmable [[graphics processing unit]]s.