Sorry, I haven't used Cybermap, but as I see noone has replied I though I would.
The easy way to check is you should have 512k less RAM then before running the comand. I'm sure there are much better technical methods to check though.
The "shadow" simply refers to the area in RAM that the ROM is copied to. The MK2 in this case is a command switch to tell cybermap which accellerator is installed.
That said. I'd recommend using BlizKick instead. It's got advanced features like ROM patching and external modules.
