BizHawk icon indicating copy to clipboard operation
BizHawk copied to clipboard
verified publisher icon TASEmulators

(NESHawk) PPU scroll glitches are not emulated

Open getCursorsExe opened this issue 8 months ago • 3 comments

These are noticeable in Super Mario Bros. I'm suggesting this because it happens on hardware (noticed this on several speedruns of the game).

(Image is from Mesen emulator)

Image

getCursorsExe avatar May 15 '25 10:05 getCursorsExe

> Image is from emulator. > Image is using a modified speedrun rom. Do you have an instance within console?

Spikestuff avatar May 16 '25 02:05 Spikestuff

I was able to find what exactly causes this. The NESDev wiki says: Writing to PPUCTRL ($2000) at the exact start of horizontal blanking may cause the PPU to start reading from the left name table instead of the right. However, I'm not sure if I'm right.

getCursorsExe avatar May 16 '25 05:05 getCursorsExe

I have real hardware here never noticed that line. How would one replicate? (Real hardware meaning ntsc nes and super mario bros plus duckhunt cart) from action set bundle. Original owner so i know its all proper and no mods

007-beep avatar Jun 18 '25 23:06 007-beep