You can try wring a file with an editor program, there is one built into the OS, or a word processing program then attempt to write it to the 3.5" drive, then try to access it. You can use standard MS-DOS/Windows diskettes with the Amiga drive, you will just have to format them, that is another test, see if the drive will format the diskette. Also if it is working ok, as soon as it's been formatted it will show up on Workbench. You should have the original Workbench disk, my first Amiga was a A500. If you have any of the original AmigaOS disks they should mount onto the Workbench as soon as you insert them into the drive and it reads it. Then you should be able to double click on it and see what's on it.
Hope this helps you out.
