if the 5.25" drive is originally a PC drive, you will need to build a logic adapter for it. my dad made me one back in the day. It was amazing to have DF1: on a otherwise limited A500.
Not sure how this applies to PC 'dos' disks. would be less heart ache to source a PC for the job.
I was just wondering if you can still purchase blank 5.25" media. looks grime and limited these days, accept if you look at
http://www.floppydisk.com/ they have a service to archive your disks for you.
I already cleared out my local supermarket of all the 3.5" blanks diskettes a few years ago was something like 50 cents a box of 10