I have a few old .dwg files (from 1993), and I can't seem to get them to open in AutoCAD 2007. I've tried a couple of dwg viewers, but none of them have worked either. Because they are 20 years old, no one knows which program was used to create them either, but since they are .dwg, I was assuming they are AutoCAD.
Does anyone know how I can open them, or at least convert them to a useable format?
All dwg files should open with any AutoCAD release that is newer than the release it was last saved in. Sounds like you have corrupt dwg files.
Viewed in a HEX viewer, the 1st 6 characters should look like AC1009 ( the 1009 designates the release in the dwg file was last saved in - R12 in this case). -David