There's been alot of talk that the IRQ counter decreases when the "A12 on the PPU bus toggles from 0-1".
What does this mean in plain english? Does it mean when bit 12 of the PPU address switches from 0 to 1 when for example setting an address via $2006?
It only decreases on toggle? Assuming the previous bit 12 was 1, and writing another 1 on bit 12 won't decrease the counter?
Another question about $A001 register. It seems pretty simple but what's the point of disabling WRAM or make it readable/writable only? Is this feature actually used in games and if so, why?
What does this mean in plain english? Does it mean when bit 12 of the PPU address switches from 0 to 1 when for example setting an address via $2006?
It only decreases on toggle? Assuming the previous bit 12 was 1, and writing another 1 on bit 12 won't decrease the counter?
Another question about $A001 register. It seems pretty simple but what's the point of disabling WRAM or make it readable/writable only? Is this feature actually used in games and if so, why?