METHOD AND APPARATUS FOR ACCELERATING THE RENDERING OF IMAGES

A direct memory access (DMA) circuit which is physically positioned with an input/output device, the DMA circuit storing a first reference value pointing to a data structure which describes a buffer portion of system memory in which data is stored for transfer to the I/O device, a value determining a position within the buffer portion of system memory beginning at which a next sequence of data is to be placed, and a value determining a position within the buffer portion of system memory from which a next sequences of data is to be copied to the I/O device, the DMA circuit including circuitry for reading data from the buffer portion of system memory beginning at the position from which a next sequences of data is to be copied and for writing the data read to the I/O device.