Ending text issues in Rockball (mapper 141/Sachen 8259A)

[kage2051]

On real hardware and accurate emulators, the text during ending/credits sequence in Rockball (an unlicensed Chew Man Fu clone) is shown in some light beige color. However, for some reason FCEUX exhibits a several years old bug where text is rendered in dark blue at least for the ending dialogue, while staff credits is not shown off at all. See images below.

I've heard BizHawk's NESHawk core has some fixes for the Sachen mapper family, but I cannot confirm as level passwords start at area 1 of each world instead of the current stage. Going to also attach a savestate that also loads on latest interim builds.

Rockball Sachen savestate.zip

[NRS-NewRisingSun]

The bug has nothing to do with mapper emulation. The game takes too long to draw to the screen, so that by the time it updates the attribute table, rendering has already started, and so the attribute table write is no longer accepted. The relative timing on this will vary by console, in particular whether it's NTSC, PAL or Dendy, but will potentially happen on real hardware as well. Nothing needs to be fixed except in the game itself.

Loading the provided save state, and then changing the region to Dendy after loading the save state without resetting, displays the text correctly.