If you have scanned Tiff or PDF files, you can try some raster to vector converters which can extract dots in images and integrate them as vector lines. I have a licensed copy of Raster to Vector Converter which supports AutoCAD R14~2009. You can get a try with it from here...
I am running AutoDWG PDF converter, and this converts thousands of drawing files into PDF automatically, to create separate PDF files per drawing, please run the software and go to the wizard step 2 of 5, and form the pull down menu "Output type" click and choose "Create individual PDF per...