To learn more on Floppy disk images, go to this Article : https://adafruit-playground.com/u/AnneBarela/pages/ms-dos-disk-images

Images included in the PicoMEM GitHub:

• sv86-720.img : Bootable Svarog86 FreeDOS Distribution : https://svarog86.sourceforge.net/
• Blank images of all size : https://github.com/FreddyVRetro/ISA-PicoMEM/tree/main/images/FDD/Blank%20images

Site that has MS-DOS 3 to 6: https://www.allbootdisks.com/download/dos.html (tested ok)
Site that has DOS 1 to 7.1: https://winworldpc.com/product/ms-dos/1x (untested)
Svarog86 (FreeDOS) : https://svarog86.sourceforge.net
SvarDOS (New relase of Swarog86): http://svardos.org/

Site that Malwarebytes flags as having riskware: bootdisk.com (BEWARE)

Software: https://www.goodolddays.net/diskimages/ (untested)

Use .img files for PicoMEM in the /FLOPPY directory .ima and IBM .dsk images can usually be renamed to .img images.
For more information, see https://www.dosdays.co.uk/topics/floppy_disk_images.php

WARNING:

• The file name (excluding .img) must not be longer that 13 Character, otherwise, the file will not be listed.<br /

Floppy image Guide Written with Anne Barela / Adafruit

Method 1: Use WinImage https://www.winimage.com/winimage.htm (GUI, shareware)

Method 2: ImDisk Toolkit Files https://sourceforge.net/projects/imdisk-toolkit/ is a WinXP through Win 10 GUI set of programs.
One is to open disk images (floppy or hard drive) as a drive letter (or directory mount point) in Windows.
Files can be copied back and forth freely.
Website - http://www.ltr-data.se/opencode.html/#ImDisk
GitHub - https://github.com/LTRData/ImDisk

Method 3: Disk Flashback
Website - https://robsmithdev.co.uk/diskflashback

Method 4: Arsenal Image Mounter - https://arsenalrecon.com/products/arsenal-image-mounter
and GitHub https://github.com/ArsenalRecon/Arsenal-Image-Mounter

To make empty formatted floppy and unformatted hard drive images, use NetDrive
https://www.brutman.com/mTCP/mTCP_NetDrive.html (Windows command line)

netdrive create floppy 360 360.img : 360KB Floppy image
netdrive create floppy 1440 1440.img : 3.44Mb Floppy image
netdrive create hd FAT16 20 20mb.img : 20MB FAT16 HDD image