DR-DOS under Virtual PC

DR-DOS is yet another DOS distribution, and one with a rather twisted history.  To quote The DR-DOS/OpenDOS Enhancement Project (http://www.drdosprojects.de):

“DR-DOS is a popular PC operating system that was originally created and developed up to version 6.0 by Digital Research. After the demise of Digital Research, it was acquired by Novell who released version 7.0 as Novell DOS 7. Despite being a commercial success, Novell lost their interest in the further development of DR-DOS and in 1996 sold it to Caldera, who changed the name to Caldera OpenDOS 7.01 and released the source code of the kernel under an Open Source license. Subsequent versions were named DR-DOS again, but unfortunately, the development model was changed back to Closed Source. Caldera Thinclients, a subsidiary of Caldera which later renamed itself to Lineo, continued the development of DR-DOS as an OS for embedded systems, before they abandoned its development in favour of Linux. The current owners of DR-DOS, Devicelogics, acquired it in November 2002 and promised to produce an 8.0 version of DR-DOS for the embedded systems market, which was released in March 2004.”

Hmmm…  Yeah.  Anyway – you can buy DR-DOS from here: http://www.drdos.com/index.htm, or you can download an evaluation version from here: http://public.planetmirror.com/pub/drdos/DR-DOS.703/dr703.exe

The real question – of course – is how does it run under Virtual PC?

Well – the install runs perfectly but on first boot you will get a hideous error message about EMM386.EXE crashing.  The reason that this happens is because the version of EMM386.EXE that ships with DR-DOS tries to directly map over the top of memory that is being used by some of our emulated hardware.

To get around this you will need to hold the shift key down while booting the virtual machine – and then type in ‘edit config.sys’ at the C: prompt. You should then add ‘EXCLUDE=E000-EFFF’ to the end of the first line in the config.sys file.

After this you should be able to reboot without any problems.

DR-DOS is one of my favorite versions of DOS as it has a lot of cool tools and options.