http://wiki.nesdev.com/w/index.php/PPU_ ... _.3E_write
The line states that writing #$30 to $2001 will produce a monochrome display. It seems that is incorrect. Writing #$1F will produce the monochrome display. Writing #$30 will only remove the background rendering and intensify red.
The line states that writing #$30 to $2001 will produce a monochrome display. It seems that is incorrect. Writing #$1F will produce the monochrome display. Writing #$30 will only remove the background rendering and intensify red.