CompuServe Messages

Mark – In order to produce a printer-plot, AutoCAD must scan the drawing and rasterize it, converting the vectors into pixels to be sent to the printer. The pixels are stored in a large memory area (bitmap), the size of which depends on the resolution of the printer and the paper size. Unfortunately, AutoCAD does not always find it possible to acquire enough memory to handle the full page. In such cases, it gets as much memory as it can, and rasterizes a horizontal strip or "band" of the drawing (as much as will fit). Then it dumps that out to the printer and starts over on the next band. Thus, the drawing's vectors may get processed several times, as indicated by the vector count resetting to zero. We're looking into ways of improving the memory usage, so that fewer passes will be needed (currently, the rasterization bitmap is acquired from the I/O page space area, so the presence of extended/expanded memory actually degrades PRPLOT performance by cutting down the amount of normal I/O page space that's available. When I've got a lot of PRPLOTing to do, I set ACADXMEM=NONE and ACADLIMEM=NONE first.)