protected virtual void OnModeControlRegisterChanged()
{
// http://www.seasip.info/VintagePC/cga.html
uint v = (uint)(X8086.BitsArrayToWord(CGAModeControlRegister));
VideoModes newMode = (VideoModes)(v & 0x17); // 10111
if ((v & vidModeChangeFlag) != 0 && (int)newMode != mVideoMode)
{
VideoMode = (uint)newMode;
}
mVideoEnabled = CGAModeControlRegister[(int)CGAModeControlRegisters.video_enabled] || VideoMode == (int)VideoModes.Mode7_Text_BW_80x25;
}
protected virtual void OnPaletteRegisterChanged()
{
if (MainMode == MainModes.Text)
{
CGAPalette = (Color[])(CGABasePalette.Clone());
}
else
{
Color[] colors = null;
uint cgaModeReg = (uint)(X8086.BitsArrayToWord(CGAModeControlRegister));
uint cgaColorReg = (uint)(X8086.BitsArrayToWord(CGAPaletteRegister));
if (VideoMode == ((uint)VideoModes.Mode4_Graphic_Color_320x200))
{
int intense = (int)((cgaColorReg & 0x10) >> 1);
int pal1 = (int)((cgaColorReg >> 5) & (~(cgaModeReg >> 2)) & 1);
int pal2 = (int)(((~cgaColorReg) >> 5) & (~(cgaModeReg >> 2)) & 1);
colors = new Color[] {
CGABasePalette[cgaColorReg & 0xF],
CGABasePalette[3 ^ pal2 | intense],
CGABasePalette[4 ^ pal1 | intense],
CGABasePalette[7 ^ pal2 | intense]
};
}
else if (VideoMode == ((uint)VideoModes.Mode6_Graphic_Color_640x200))
{
colors = new Color[] {
CGABasePalette[0],
CGABasePalette[cgaColorReg & 0xF]
};
}
if (colors != null)
{
for (int i = 0; i <= colors.Length - 1; i++)
{
CGAPalette[i] = colors[i];
}
}
}
}
public override ushort In(uint port)
{
if ((((port == ((uint)(0x3D0))) || (port == ((uint)(0x3D2)))) || (port == ((uint)(0x3D4)))) || (port == ((uint)(0x3D6)))) // CRT (6845) index register
{
return((ushort)(CRT6845IndexRegister));
} // CRT (6845) data register
else if (((((port == ((uint)(0x3D1))) || (port == ((uint)(0x3D3)))) || (port == ((uint)(0x3D5)))) || (port == ((uint)(0x3D7)))) || (port == ((uint)(0x3B5))))
{
return((ushort)(CRT6845DataRegister[CRT6845IndexRegister]));
} // CGA mode control register (except PCjr)
else if (port == ((uint)(0x3D8)))
{
return(X8086.BitsArrayToWord(CGAModeControlRegister));
} // CGA palette register
else if (port == ((uint)(0x3D9)))
{
return(X8086.BitsArrayToWord(CGAPaletteRegister));
} // CGA status register
else if ((port == ((uint)(0x3DA))) || (port == ((uint)(0x3BA))))
{
UpdateStatusRegister();
return(X8086.BitsArrayToWord(CGAStatusRegister));
} // CRT/CPU page register (PCjr only)
else if (port == ((uint)(0x3DF)))
{
#if DEBUG
//stop
#endif
}
else
{
base.CPU.RaiseException("CGA: Unknown In Port: " + port.ToString("X4"));
}
return((ushort)(0xFF));
}