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[NTVDM:SVGA]

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Fix the refresh rate calculation, again.


svn path=/trunk/; revision=72489
This commit is contained in:
Aleksandar Andrejevic 2016-08-28 16:17:14 +00:00
parent 75ece18c55
commit 493ad03e52
1 changed files with 27 additions and 8 deletions
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35
reactos/subsystems/mvdm/ntvdm/hardware/video/svga.c
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@ -1118,6 +1118,22 @@ static BYTE WINAPI VgaReadPort(USHORT Port)
VerticalRetraceEnd = VerticalRetraceStart + (VgaCrtcRegisters[VGA_CRTC_END_VERT_RETRACE_REG] & 0x0F);
if (VgaGcRegisters[VGA_GC_MISC_REG] & VGA_GC_MISC_NOALPHA)
{
BYTE MaximumScanLine = 1 + (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] & 0x1F);
if (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] & VGA_CRTC_MAXSCANLINE_DOUBLE)
{
VerticalRetraceStart <<= 1;
VerticalRetraceEnd <<= 1;
}
else
{
VerticalRetraceStart *= MaximumScanLine;
VerticalRetraceEnd *= MaximumScanLine;
}
}
/* Calculate the horizontal blanking duration in cycles */
HblankStart = VgaCrtcRegisters[VGA_CRTC_START_HORZ_BLANKING_REG] & 0x1F;
HblankEnd = VgaCrtcRegisters[VGA_CRTC_END_HORZ_BLANKING_REG] & 0x1F;
@ -1644,15 +1660,18 @@ static VOID FASTCALL VgaHorizontalRetrace(ULONGLONG ElapsedTime)
VerticalRetraceStart |= (VgaCrtcRegisters[VGA_CRTC_OVERFLOW_REG] & VGA_CRTC_OVERFLOW_VRS8) << 6;
VerticalRetraceStart |= (VgaCrtcRegisters[VGA_CRTC_OVERFLOW_REG] & VGA_CRTC_OVERFLOW_VRS9) << 2;
if (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] & VGA_CRTC_MAXSCANLINE_DOUBLE)
if (VgaGcRegisters[VGA_GC_MISC_REG] & VGA_GC_MISC_NOALPHA)
{
VerticalRetraceStart <<= 1;
VerticalTotal <<= 1;
}
else
{
VerticalRetraceStart *= MaximumScanLine;
VerticalTotal *= MaximumScanLine;
if (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] & VGA_CRTC_MAXSCANLINE_DOUBLE)
{
VerticalRetraceStart <<= 1;
VerticalTotal <<= 1;
}
else
{
VerticalRetraceStart *= MaximumScanLine;
VerticalTotal *= MaximumScanLine;
}
}
/* Set the cycle */