Have written previously about my experiments with the very excellent Greaseweazle; but that was reading things like my old Kings Quest 5.25″ floppy disks from my modern 12th Gen Intel PC running Windows 10.

Recently I acquired some old pc hardware and put together a retro 486-DX pc. To that end, I needed to create a DOS boot disk for this old system. That meant I needed to write a 1.2mb DOS boot disk.

Previously I used some boot disk images to create an old DOS virtual machine running Windows 1.0. For that, I used a bunch of archived boot disks images from WinWorld archive.

But how do I write these little beasts?

I floundered around with greaseweezle’s command line but this guide from Tech Tangents really helped out. There’s clearly a lot more I need to learn, but this got me a bootable 5.25″ 1.2mb floppy disk. I was able to test it on 2 different drives, and both worked. So, that’s pretty sweet!

Greaseweezle command line samples

How to write DOS 6.22 image to a 5.25″ 1.2m floppy drive attached to the ribbon cable right before the cable twist:

gw write --drive b --format ibm.1200 Dos6.22-5.25.img

To write a DOS 3.30 image to a 5.25″ 360k floppy drive attached to the ribbon cable right before the twist:

gw write --drive b --format ibm.360 DOS330-360k.img