I've made a few enhancements to the DR-DOS boot stick that I made, so here are the details. Just copy the files mentioned to the root of the boot disk. I believe that everything used is free for non-commercial use. Here goes:
The OAKCDROM.SYS generic CD-ROM driver (will work with most IDE CD-ROM drives) I got my version from here. Open the zip file and look inside the "Floppy" subfolder. Just copy OAKCDROM.SYS to the boot disk.
In addition to the CD-ROM driver, I've used a MSCDEX replacement called SHSUCDX, which is linked to from here. I've downloaded the "shcdx33e.zip" version. Just copy the SHCDX33E.COM file to the boot disk.
For memory management I've added two things:
HIMEMX - copy both EXE files
CWSDPMI - just copy CWSDPMI.EXE (in the bin folder)
And finally, I've added a RAMdisk driver... we need to copy the SRDISK.EXE and SRDXMS.SYS files.
To get all those files to work we also need to edit AUTOEXEC.BAT and CONFIG.SYS:
SHCDX33E /d:CD001 /l:X
SRDISK 10240 /E
So now if we boot from the memory stick we'll have X: mounted as the CD-ROM (if you have one) and the current drive will be an empty 10Mb RAM drive. We also have better memory management. It should be a reasonable DOS system, and to the best of my knowledge everything I have used is free for non-commercial use - good for the hobbyist that wants to run a DOS machine.