[ScottBeebiWan]

Okay, so I changed the coin scoreboard sprite in YYCHR, and then this happened. 0.o

plz halp

[MathUser2929]

Try copy pasting the coin sprite from a fresh rom. Then never change it again.

[ScottBeebiWan]

Try copy pasting the coin sprite from a fresh rom. Then never change it again.

why tho
I've done this successfully before

[FCandChill]

Comment removed because reasons...

[Dr. Floppy]

Sprite-Zero shit detection.

You need to alter the half-coin sprite (Sprite #FF) to match the bottom three lines of your new HUD-display background coin tile #2E.

[FCandChill]

Comment removed because reasons...

[Disch]

Hm ... that's really interesting. I'm reading about it on NesDev. Is there any specific reason why this occurs?

Splitting the screen to have a stationary status bar with a scrolling main display requires a timed write to occur in the middle of frame rendering.

Neither SMB's cartridge nor the NES itself offers an IRQ which will cut in when the appropriate time occurs, so the game uses sprite 0 hit to mark it.

If you change the sprite, and not the matching BG tile (or vice versa), it changes when the "hit" occurs, and thus screws up the timing of when the game splits the screen.

[MathUser2929]

I think there's a few sprites in SMB you can't edit or it can mess things up. I remember having problems when I edited a few sprites.

[Disch]

I think there's a few sprites in SMB you can't edit or it can mess things up. I remember having problems when I edited a few sprites.

There's a "sprite" half-coin and matching "bg" full coin that is drawn over it.

Aside from those, the only graphics that you can't change are the scrambled tiles -- and it's because those are not actually graphics but data used to construct the title screen.