There is no other info on how those three bits can be interacted with, so I am guessing people are assuming from the documentation and/or ROMS and nothing else.On the original NES/Famicom, and on the VT02+ with Address Extension Disabled, both background and sprite tiles are indexed by an eight-bit number taken from the nametable for backgrounds and byte 1 of each sprites' OAM data. Address Extension adds three bits to form an eleven bit tile number, which can be seen as performing an implicit bankswitch for each tile. VR Technology's VT03 Demonstration ROM uses Background Address Extension to show off the use of more than 256 Hanzi characters on a single page
And please: How does one operate 8x8 attributes on VT systems? I would really appreciate an answer, thank you!
EDIT: 777th post!!! WOO!!!