The DOS 6.22 Disk 1 should be bootable, so if you have the floppy image that's all you need. But how do you plan to write it to a floppy from a modern Mac? Do you have a USB drive or something?

EDIT: assuming you have some sort of floppy drive, you can just write the image using dd:

1dd if=<image file name> of=/dev/fd0

where fd0 is the name of the floppy drive device, but not sure what you have there.

I'll give that a try. Yes, I have an external USB floppy drive for my Mac. One thing I want to understand is how the floppy signals to the computer that it's bootable. Is it just a function of what files are on the disk or is there something written to a hidden part of the disk? And as such, can I just copy certain files to the disk to make it bootable? I know you can create a bootable MS-DOS disk by using the DOS command "format /s". What exactly is that doing to make the disk bootable and can this be done on my Mac?

It is in the disk image itself. When a PC tries to boot from floppy, it reads the sector 0 of the disk into memory and executes code from there. For non-bootable floppies, all the code does is display a message such as "Please insert a system disk" or something like that (it depends on what tool was used to format). For actual bootable floppies, it reads the rest of the OS boot code from the system files on the disk and then executes it, which in the case of MS-DOS ends up with COMMAND.COM being executed as well as CONFIG.SYS/AUTOEXEC.BAT if they are present.

So yes, all the information for booting is in the disk itself, but just copying the hidden system files to a regular disk is not enough as you also need the bootstrapping code I mentioned in sector 0 which is written during format. But as I explained above, the MS-DOS 6.22 Disk 1 is bootable, so if the image was properly created then writing it to a disk should work.

That's exactly the information I was looking for. Thanks for explaining it. I've had success using dd as you suggested and have also discovered balenaEtcher which is a slick open source tool for direct writing disk images on Mac OS. Thanks for pointing me in the right direction.