Back in December, as part of the #DOScember event across Reddit and other places, I converted the IBM PC DOS 2000 (that is, PC DOS 7.01) virtual disk that was included with Connectix (later Microsoft) VirtualPC into VirtualBox format. You can still download VirtualPC if you wish — here's the 2004 version. The final version was 2007 SP1 as far as I know.

I made the PC DOS VDI available for download and wrote a blog post announcing it.

This was an unmodified installation of PC DOS 7.01, complete with non-working Connectix "guest additions" for DOS. I just converted the format.

Well, I have now gone a very small way towards improving that image for VirtualBox users.

• I've tweaked the memory management for VirtualBox (I am using the latest version at the time of writing, 6.1.18), so now DOS has Upper Memory Blocks available and both EMS and XMS memory – and a whopping 618kB of conventional memory available (that is a lot for DOS!);
• I have installed IBM's own IDE CD driver, and MSCDEX and the SmartDrve disk cache;
• I've enabled a mouse driver;
• I've enabled ANSI.SYS so that you can change the number of rows shown on-screen. 

So here is a compressed disk image, 2.4MB in size. Just unzip it (it is only 11MB uncompressed), create a default DOS VM in VirtualBox — if you call it something like "PC DOS 2000" it will register the word "DOS" in the filename and configure a VM for DOS, with 32MB of RAM and so on. The Virtual Disk Image is called PC_DOS_2000.VDI and contains a FAT16-format C drive of 2GB. 

Share and enjoy.