private void updateTimer()
{
if (GameBoyCPU.getBit(6, RTCRegisters[4]) == 0)
{
DateTime curr = System.DateTime.Now;
TimeSpan currSpan = curr - start;
RTCRegisters[0] = (byte)(currSpan.Seconds);
RTCRegisters[1] = (byte)(currSpan.Minutes);
RTCRegisters[2] = (byte)(currSpan.Hours);
RTCRegisters[3] = (byte)(currSpan.Days);
if (currSpan.Days > 255)
{
//Rollover
RTCRegisters[4] = GameBoyCPU.setBit(0, RTCRegisters[4]);
}
if (currSpan.Days > 511)
{
//Set overflow bit.
RTCRegisters[4] = GameBoyCPU.setBit(7, RTCRegisters[4]);
//Unset rollover
RTCRegisters[4] = GameBoyCPU.resetBit(0, RTCRegisters[4]);
start = start.AddDays(512);
}
}
}
public bool ResetJoyPadBit(byte key)
{
bool isHighToLow = (GameBoyCPU.getBit(5, memory[0xFF00]) == 1) ? true : false;
joypadState = GameBoyCPU.resetBit(key, GameBoyMemory.joypadState);
return(isHighToLow);
}
public void setSpeed()
{
byte speedBit = getSpeedBit();
if (speedBit == 0)
{
setSpeedBit();
}
else
{
resetSpeedBit();
}
speed = (uint)((GameBoyCPU.getBit(7, memory[KEY1])) == 1 ? 2 : 1); // if 1 we switch to normal speed (1) and if 0 we switch to double speed (2)
}
private void updateControl(byte data)
{
DateTime e = System.DateTime.Now;
TimeSpan diff = e - start;
byte dayBit = GameBoyCPU.getBit(0, RTCRegisters[4]);
if (dayBit == 1 && (data & 0x1) == 0)
{
start = start.AddDays(256);
}
else if (dayBit == 0 && (data & 0x1) == 1)
{
start = start.AddDays(-256);
}
LatchRegisters[4] = RTCRegisters[4] = data;
}
private void updateDays(ushort dayReset)
{
DateTime e = System.DateTime.Now;
TimeSpan diff = e - start;
if (GameBoyCPU.getBit(0, RTCRegisters[4]) == 1)
{
dayReset += 256;
}
if (dayReset < diff.Days)
{
ushort diffDays = (ushort)(diff.Days - dayReset);
start = start.AddDays(diffDays);
}
else if (dayReset > diff.Days)
{
ushort diffDays = (ushort)(dayReset - diff.Days);
start = start.AddDays(-diffDays);
}
}
private byte getJoyPadState()
{
byte res = memory[0xFF00];
// flip all the bits
res ^= 0xFF;
// are we interested in the standard buttons?
if (GameBoyCPU.getBit(4, res) == 0)
{
byte topJoypad = (byte)(joypadState >> 4);
topJoypad |= 0xF0; // turn the top 4 bits on
res &= topJoypad; // show what buttons are pressed
}
else if (GameBoyCPU.getBit(5, res) == 0) //directional buttons
{
byte bottomJoypad = (byte)(joypadState & 0xF);
bottomJoypad |= 0xF0;
res &= bottomJoypad;
}
return(res);
}
private byte getSpeedBit()
{
return(GameBoyCPU.getBit(7, memory[KEY1]));
}