> I want to try the next step, which is copying files onto the TD0 disk image file. You
> said I should use IsoBuster to do this, correct? I looked up IsoBuster and I don't
> see how that is the correct tool to use for that. I haven't downloaded it yet, but I
> want to be sure that is what you meant. Do I do use IsoBuster in a Windows
Well, IsoBuster not only lets you manage ISO files but floppy disk images too. However I doubt it can handle RX50 media and so far I've only tried with MS-DOS FAT formatted diskettes. That's why I told you to get your files copied to an IBM PC environment first, so you can read/write RX50 diskette images with it using a special driver and then move the files on them so you can finally use them on your Rainbow 100 emulation.
Looking at the Rainbow 100 wiki entry the system also supports hard drives, I'm not sure if MAME has support for them too. If that were true you could also save a few steps by copying your files to a hard drive image and then use chdman tool so you can attach it to the emulation. This thread here has how to do it on IBM PC systems, maybe it could help you with Rainbow 100 too. Mhh, that topic talks about PowerISO instead of IsoBuster, maybe I'm confusing the program. Anyway, it doesn't hurt to try both of them.