Installing MS DOS Without floppies

So how many of you old PC collectors have had this one? You are trying to get MS-DOS onto an old PC, you either have no floppies, no floppy drive or both. Sure, getting DOS 6.22 to boot from USB is easy but if you actually want to use the installer, well that’s not going to happen without floppies.

If you search Google there is a wealth of info on how to make a bootable 6.22 USB drive but nothing on how to make the installer work. It needs floppies and you can’t just copy files somewhere and run from that. So, how do we resolve this?

I had this very issue recently. After a protracted fight with an old laptop I got it booted and then I was left with a choice. FreeDOS or copied MS-DOS files from a floppy image with most of the installation missing. FreeDOS has behaved “odd” on this hardware and there are warnings about running Windows under it here. I’ll be running 3.11 on this AND some of my older software which hooks a LOT of interrupts so I’m not feeling comfortable here. I’m also curious as to how well it’ll behave with DPMI overlays for the same reason, everything points to 386 mode being the issue. Sure the basic MS-DOS install works but its missing a lot, EMM386, DosShell, DriveSpace etc so I want the lot. Enter Turbo image…

Turbo image is a TSR (remember those?) That allows you to mount a .img file as a floppy drive, A or B an as far as I have found, everything is happy with this situation. The TSR can be popped up at any time with CTRL+ALT+T and you can change image. It can be found in the old SimTEL archives but a LOT of these are just lists of dead links. It was (at last check) available through here, and yes, you CAN install MS-DOS with it, with some mods to your boot disk.

I’ve found the easiest way to do this was with virtualbox. You need to be able to mount your install disk 1 image somehow and edit it, and you’ll need to transfer two files to it. One of the files you need is himem.sys from MS-DOS and is compressed on disk 2. In my case I span up a VM, installed MS-DOS from floppy images and then shut everything down. If you are using Widows 10+ you can now add that VHD in disk management and access the virtual drive to copy from the archive over. Unmount the image and boot into dos in the virtual machine. Re-Connect the first of the three install floppies to the virtual machine and copy HIMEM.SYS and TI.COM over to the first installation disk. You’ll then need to edit the config.sys on the install floppy to load himen (add device=himem.sys) and edit autoecec.bat to launch Shut everything down, and you now have your original two floppy images and your now modified image. I’ve also uploaded my modified image here if you don’t want to go through the above. However, if you do and you have to resort to a manual install (Partition and system format the HD from a boot disk), you’ll have the whole DOS file structure to hand.

Now you need those images. You have two ways to do this. In my case I had an empty data drive in the form of a second CF card. The card was formatted IN the target machine to stop Windows doing anything “clever” and then the remaining two image files were copied over. You could also add a small (4Mb) partition to the end of your target drive, format this and copy the image files there. Where-ever you put them they must be visible. you could add CD/ASPI drivers to the first disk and have a CD-ROM/SCSI drive/ZIP/USB drive available for the images. I found the second drive and partition methods easiest as it was far less faff. Also in my case, these were my only options.

Boot from your disk 1 image and proceed as normal, when prompted for disk 2, press CTRL+ALT+T and you’ll get the popup. Select your disk 2, escape and press enter, do the same for disk 3 and you are done. Also, this does the install at the speed of your RAM and target drive, its FAST!

Reboot when prompted and all should be well. So far I’ve used Turbo Image to get Turbo Pascal, DOS and Norton Utilities installed without a hitch. Its definitely one to leave on the machine and the machine I’m working on not having a working floppy is now less of an issue.