dtgreene: Welcome to the sort of issues that video game preservationists face. It may still be possible to run the original versions of these games on your computer, but doing so can be tricky.
If you are on an Intel Mac (not an M1), you might need to dual boot into Windows or Linux in order to play this game. (If you're using a Mac that won't let Linux access the hard drive, use an external one.) Fortunately, these games *do* run under WINE, so Linux is a good option here if you don't want to acquire a Windows license.
If you are on an Apple Silicon mac, then things get a lot harder. You *might* be able to get away with something like QEMU or another emulator running Windows or Linux, provided you turn off hardware acceleration.
Unfortunately, GOG only offers the final patch versions for the classic versions; if you, for whatever reason, want to play the 1.0 versions (*without* Tales of the Sword Cost and Throne of Bhaal installed), you will unfortunately need to look elsewhere.
Thanks dtgreene, I've just gone down the route of digging out an old desktop pc so I can load the GOG versions on that and play them there.