The first thing to look at there would be the OS used. DOSBox works with old MS Dos games and apps. The old Commodore games may have used DR Dos or a UNIX form of some type. I think that's where you are getting stuck.
OS: ROM BASIC !!! http://oldcomputers.net/c64.html
ut ooooooo..... pre dos days there alright!
The other thought that the reason the emulators are not working would be that some of the old files are missing or you are not entering the correct commands to see those mount the virtual drive and load the games.
One place that seems to have a quite a bit rolled up into catagories to look over for game instructions, emulators, and other old archives is seen at http://www.worldofspectrum.org/WoSFAQ.html
I think you will end up in a place like that in order to find what you need there. The closest I've worked with here for anything prior to an I286 seeing any games was something as old as the C64 namely an Epson HX-20 used by the sale dept. in those days.
Those saw some 512kb over the Commodore's 64kb then. A good page on that ancient history is seen at http://www.artscipub.com/history/hx20/