Restore correct CGA compatible mode behavior in (S)VGA. #3943
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| svga->hdisp_old = svga->hdisp; | ||
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| if ((svga->bpp <= 8) || ((svga->gdcreg[5] & 0x60) == 0x00)) { | ||
| if ((svga->bpp <= 8) || ((svga->gdcreg[5] & 0x60) <= 0x20)) { |
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This is not a critique of this commit, but a critique of how stuff unfolded in order to support [INSERT SPECIFIC SVGA ADAPTER HERE]. All things considered, this pull request does fix the issue.
What's happening here will need to be tidied up at some point, because so far it seems that this was written to fix a specific adapter, but... well, I can tell you right now that the second condition in the OR will break on an S3 Trio when someone decides to get a bit funky (SVGA modes override VGA modes on S3 Trio, though the extent hasn't been fully worked out yet) and actually, maybe someone won't even need to get funky for this to break.
However, fixing this will also require working out which cards this workaround was required for. From what I can tell, this was for the Matrox MGA cards.
Anyway, this PR should fix the problem, at least for now. But we really do need to track all the differences for the SVGA chipsets we emulate.
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See above.
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