What resolution should I scan a missing print set at?

[Noel Chiappa]

Hi all, I have a PDP-11 print set (MP00196, M9301 Bootstrap/Terminator) which
is not online. I wish to scan my copy, and donate the scan to all the
repositories.  What resolution should I scan it at?

I looked at a couple that are available as TIFFs, and they claim to be 600 dpi
- that can't be right, is it? If it is, no problem, I'm happy to do it at that
resolution, but I just don't want to do silly overkill.

Thanks!

        Noel