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TomHarte / CLK

A latency-hating emulator of: the Acorn Electron and Archimedes, Amstrad CPC, Apple II/II+/IIe and early Macintosh, Atari 2600 and ST, ColecoVision, Enterprise 64/128, Commodore Vic-20 and Amiga, MSX 1/2, Oric 1/Atmos, early PC compatibles, Sega Master System, Sinclair ZX80/81 and ZX Spectrum.
MIT License
945 stars 52 forks source link

Apple II color banding on left side of screen on 2011 MBP #1277

Open ryandesign opened 10 months ago

ryandesign commented 10 months ago

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 81ad8646596321215840c33675b0cfb9644ea549 due to https://github.com/TomHarte/CLK/issues/872#issuecomment-1862366062) 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:

colorbands

Those should all be stripes of solid colors.

ryandesign commented 10 months ago

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.