`   Just out of curiosity ... while I did know that ``bright black`` is still as black as the ``dark`` one, I could swear that I did see the difference with my setup back then (~1984-1987, ZX Spectrum 48K issue 3 connected using RF/PAL to a Grundig colour TV, don't remember the model). I wonder whether this has been done entirely in digital domain or is the brightness component added in the analog section. The reason why I am saying this is that ``bright black`` may actually mean ``make the signal noise brighter on black`` which would produce exactly the effect that I saw - barely visible, non-as-uniform extremely dark grey... Does anyone know whether there is any detailed schematic diagram of Spectrum anwywhere?  `