Hmm, the "o" button on whatever keyboard your made your original post on works well enough, as near as I can tell.
Did you mean your "zero" button? Most keyboards these days have two of those, don't they?
Otherwise, you could alter syscons(4) to re-route some other key to output zero, I suppose. Ah, here 'tis, in BSD, rebuild syscons with option "ZERO_KEY_BUSTED_USE_SHIFT" ... for Mac OS, used the older option "NO_ZERO_USE_ANY_KEY" ... I think maybe that's what Buzz was referring to. Or maybe he meant to hack the memory buffer to cause ones to become zeros via means of bitwise shifting. He's very good at such, y'know ....
Not sure about windows, as it's closed source. Probably you can wait for Vista to come out, and it'll just read your mind and type the zeros for you.....
😃