Reading old 5.25" dos floppies on a Amiga?

[Oldsmobile_Mike]

CrossDOS can do that for you.  It's bundled with most newer versions of the Amiga operating system.  There's also programs like "MessyDOS" and "DOS2DOS" which allow you to read PC-format disks.

Sorry to keep pointing you to google, but there's a wealth of information already out there on this subject:

https://en.wikipedia.org/wiki/CrossDOS

http://www.zimmers.net/cbmpics/damigas2.html


*I assume when you say (quote) "I have an external 5.25" floppy drive" that you have one which is made for an Amiga, correct?  Be aware that the common Amiga 1020 (5.25" floppy drive) is only double density (360KB), and many PC floppies are 1.2MB (high density).  Probably a good idea to check the disks before you try reading them.

Bonus tip: apparently the A1020 can also read Atari 8-bit, Apple II, and C64 format floppy disks, with the right utilities.  I had one back in the day and never even knew!  

[Oldsmobile_Mike]

Is this drive capable of reading 720kb floppies?

I think you have your formats confused. 720kb is the standard capacity of a PC double density 3.5" disk.