it's not TB of ROM. It' much, much more: 2^(2^20) addresses... Even if you're faking it and the addresses aren't real (inevitable with those numbers), you're

it's not TB of ROM. It' much, much more: 2^(2^20) addresses... Even if you're faking it and the addresses aren't real (inevitable with those numbers), you're still just cheating and storing data in a multi-megabyte dynamic (not ROM!) program counter. After all, you need to distinguish all those addresses...