If your question is related to our gallery, the reason why most of the screenshots for games before 2001 are missing is that we've had a major crash in 2001 and we basically lost all our archive
I try to re-add some old screens when I have time, but it's a time-consuming process.
If you wanna know how to grab screens for older games, hypersnap will work fine for all win32 games. For DOS games, there are some good soft for that too (but you can forget it if you have winxp)