Installing MS-DOS on Qemu

MS-DOS is a great 'little' OS for bootstrapping other OS's. If you are going to install Windows 95, Windows 98 or Windows Me, Novell Netware, Windows NT 3.1/3.5/3.51/4.0 or even setup a dual boot OS/2 VM it's best to start here.

First MS-DOS 5.0 & 6.0 (6.1/6.2/6.22) are the 'best' versions to load as they can support a hard disk up to 2GB in size. MS-DOS 4.0 can only use 32mb partitions, however it can use extended partitions.. So you can have LOTS of 32mb partitions. MS-DOS 3.x can only use a single 32MB partition.. I wouldn't waste time with MS-DOS 1, as it has no support for hard disks, and early 2.0 doesn't have support for directories.

In this example I'm going to install MS-DOS 6.22. It's very straight forward.

Create a hard disk

The first step is to create a hard disk image. I'm going to create a 2GB one, so the syntax is:

qemu-img create -f qcow msdos.disk 2G

Installing MS-DOS

MS-DOS uses the BIOS for all IO so the ISA/PCI thing doesn't matter. Also the installation, and all files will run on 8088/8086 or higher so you don't have to worry about any cpu flags. MS-DOS himem.sys will only see a maximum of 64MB of ram. So there is no point in letting qemu grab 128mb of ram.

qemu -hda msdos.disk -m 64 -L . -fda dos622_1.img -boot a