Abstract: In raster data plotting of graphic information, vector data comprising the plot is generated by the host computer via the user's application program. For maximum plotter efficiency and relief of host system time, vector to raster conversion is carried out by an offloading processor which receives vector data ordered in vector bands constituting the plot. Vector data in each band is received in random order and is initialized for vector computational values. The computational values for each vector are stored in parallel format in a vector memory in the initialized random order for subsequent retrieval in parallel format for vector to raster processing of each scan line of the band and then restored in parallel format in the vector memory if the vector is still active. A vector type, designating vector orientation relative to Cartesian coordinates, is one of the computational values for each vector.