Super Mario Advance - Graphical issues

[Blaziken257]

Firmware versions

First seen on Pocket OS v1.1 beta 7 and still remains as of v1.1. Untested on versions prior to v1.1 beta 7.

Description

Super Mario Advance has a couple of graphical issues with stray pixels that occur on a Pocket. These issues do not occur on real GBA hardware or on mGBA which aims for accuracy. The issues have been observed when run from an Everdrive GBA X5 Mini or from the Spiritualized openFPGA GBA core. (It is possible that the issues also occur on a real Super Mario Advance cart, since other unrelated Pocket issues, when they occur, happen on real carts, flashcarts, and openFPGA cores all at once. However, I do not have a real Super Mario Advance cart to test with.)

Comparison screenshots are provided below, with the first screenshot from the Pocket and the second screenshot from mGBA. mGBA is consistent with real hardware when it comes to the lack of stray pixels.

Player Select Screen

Note that there are a few stray pixels that appear momentarily beneath the left curtain on the Pocket.

Pocket	mGBA

Stray pixels in background

In nighttime levels, such as World 2-1, a vertical column of pixels flickers in around the same spot (horizontally) as the issue above. This is hard to show with a single screenshot since there are multiple pixels that flicker, but you can see a stray brightish pixel about halfway between the "World 2-1" graphic and the background desert graphic, vertically.

NOTE: mGBA does have an unrelated emulation issue where it doesn't show vertical tearing in the leftmost fourth of the gradient (i.e. the gradient is a pixel lower in this area), so ignore this. (The tearing seen in the Pocket also shows up on real hardware.) However, mGBA is consistent with real hardware when it comes to the stray column of pixels.

Pocket	mGBA