Apple II color banding on left side of screen on 2011 MBP

[ryandesign]

Trying Clock Signal on Linux Mint 21.2 on a 2011 13" MacBook Pro for the first time, I see a color problem in Apple II emulation that I don't see on macOS on a 2012 15" MacBook Pro with Retina Display (neither in the Xcode/Metal UI nor in the scons/SDL/OpenGL UI).

Using the latest code in git (but reverting 81ad864 due to #872 (comment)) built for SDL/OpenGL using scons and this test program:

1GR:C=1:FORI=0TO39:COLOR=C:HLIN0,39ATI:C=C+1:IFC>15THENC=1
2NEXT

I get this output:

Those should all be stripes of solid colors.

[ryandesign]

Wondering if the problem had been introduced at some point recently, I built an old version of the code from 2019 and the problem was present there as well.

I then tested in macOS Monterey 12.7.2 on the same 13" 2011 MBP and the problem is still present, whereas it is not present on the same macOS version with the same (MacPorts) libsdl2 2.28.5 install on the 15" 2012 Retina MBP. So the only variable is the video card?

The 13" 2011 MBP exhibiting the problem has Intel HD Graphics 3000 384 MB.

The 15" 2012 Retina MBP that doesn't show this problem has NVIDIA GeForce GT 650M 1 GB.