Not sure what you mean by "the machines were real." I wasn't suggesting that the IBM PC never existed. I was acknowledging that there are varying 'levels' of emulation. This one requires ROMs.
The way you wrote it made it seem like you thought the program wasn't an emulator or that the machines it emulated weren't real. So you quoted it for emphasis. That's why I asserted that it was by writing that the machines it emulated were real.
Follow up: I couldn't figure out exactly why this bugged me so I looked up and found this grammar rule around quoting.