[toast0]

For the Apple II, there's Apple Disk Transfer ProDOS[1] to transfer disk images from a Java program on a modern computer to a disk on the Apple; there's a similar bootstrapping process which is fun to watch. There's a video tutorial which shows the sequence: https://youtu.be/1xworYThmMI?t=157

[1] https://www.adtpro.com/

[StillBored]

I did something like that a few years back when I wanted to transfer a bunch of old floppies from my Apple ][ to a PC emulator. Eventually I worked my way to a IIGS with appletalk connected to a 68K mac with both appletalk and ethernet which FTP'ed things to my PC.

These days a far easier way to do this is to pick up one of the apple floppy->SD emulators. Replace one of the actual floppy drives with the emulator hardware and use Copy II+/etc to copy the floppy images to SD, which can then be plugged into your PC with them all stored as nice little disk images.