(re: Space Quest EGA Original Disk)
You cannot make a backup copy from your original disk because the disk is copy-protected. I take it that you only own the original disk for the game, not the “3D-animated adventure game reference card”, otherwise you would know this. Sierra stopped using disk-based copy-protection sometime in 1988. Programs like CopyIIPC can defeat SOME copy protection schemes and create working copies, but it can not defeat Sierra’s CPC.COM, because the PC’s floppy controller can not write the copy-protected track.
Concerning software emulators: Yes, they *could* emulate the copy protection, but NOT by mounting the game directory as someone suggested (the copy protected track is not allocated to any file), and not with the file format all emulators (MESS, Dosbox, Tand-EM) use to hold disk images. The semi-popular TeleDisk file format could hold the necessary information (even though TeleDisk can not create a working duplicate of the disk itself), but no emulator supports this format.