Hi everyone,

Long-time lurker, first time poster! I'm hoping I can get some technical advice regarding backing up 3.5" floppies, especially ones that don't want to mount or give me checksum/copy errors while imaging.

Basically,. I sometimes do IT/programming work for a cognitive psychology lab that's been around since the late 70's, and they have a ton of archives and old tech going back about that far (half the walls are covered in the mounted boards of a decommissioned PDP-11). Because of my knowledge and love of old computers, I'm often asked by the head of the lab to try and find old data, experiment programs, and unfinished manuscripts from these archives. Anyway, most of the data that ever made it onto a CD backup or USB backup have been archived on a giant external drive for easy searching, but just recently we found a large set of floppies, Zip drives, and two Iomega Jaz drives (!) that we don't think were ever archived, so I've been picking away at that for a few days:

All the Zip disks were archived easily using an iMac G4 and a USB Zip drive (needed a PowerPC-era machine for archiving Mac content without breaking resource forks), but the floppies have given me a bit more trouble. I've been using an old PowerBook 1400cs to make images of the floppies using Disk Copy 4.2 and the first 20-30 went pretty well, but on the 5th box of floppies and beyond the drive has gotten progressively worse at reading disks, getting far more checksum errors and failures to mount entirely:

Are there any kinds of maintenance steps I should be taking to keep a 3.5" floppy drive (or diskette) in good condition for this kind of task? For disks that don't mount, or mount fine but give bad checksum errors when imaging, are there any special methods or special hardware that can be used to try and resolve things, or are those diskettes a lost cause? Are there any brands/models of floppy drive that are known to be more reliable than others? I've read a little about tools like the Kryoflux, but from what I can tell it doesn't play well with Mac diskettes (which make up over 50% of the material here).

Thanks in advance! I really appreciate any expertise or advice the community has to offer.