You didn't need hardware add-ons, only a 3.5 inch floppy drive (didn't run from tape). I never used cp/m programs on it, but there were quite a lot of cracked games that used msx-dos to run. And if I remember correctly, the Hitech compilers were .com files as well. I programmed in hex (just typing hex in memory addresses) with a memory monitor tool. I didn't even know the assembly instructions of what I was doing. I learned assembly & c using Hisoft. Before I switched to PC I knew how to create both 'bare metal' and msx-dos programs in assembly and c.

I knew about cp/m, but never had (as far as I know) any software for it.