public void Poke(ushort address, byte value)
{
// Timer addresses can be handled separately
if (address >= Mikey.Addresses.HTIMBKUP && address <= Mikey.Addresses.TIM7CTLB)
{
int offset = address - Mikey.Addresses.HTIMBKUP;
int index = offset >> 2; // Divide by 4 to get index of timer
Timer timer = Timers[index];
switch (offset % 4)
{
case 0: // Backup value
timer.BackupValue = value;
return;
case 1: // Static control
StaticControlBits control = new StaticControlBits(value);
timer.StaticControlBits = control;
// "It is set on time out, reset with the reset timer done bit (xxx1, B6)"
if (control.ResetTimerDone)
{
timer.DynamicControlBits.TimerDone = false;
}
if (control.EnableCount || control.ResetTimerDone)
{
timer.Start(device.SystemClock.CompatibleCycleCount);
ForceTimerUpdate();
}
return;
case 2: // Current value
timer.CurrentValue = value;
ForceTimerUpdate();
return;
case 3: // Dynamic control bits
timer.DynamicControlBits.ByteData = value;
return;
}
}
if (address >= Mikey.Addresses.AUD0VOL && address <= Mikey.Addresses.AUD3MISC && SoundEnabled)
{
int offset = address - Mikey.Addresses.AUD0VOL;
int index = offset >> 3; // Divide by 8 to get index of audio channel
AudioChannel channel = AudioChannels[index];
// "FD20 -> FD27 Audio channel 0, links from timer 7"
// "FD28 -> FD2F Audio channel 1, links from audio timer 0"
// "FD30 -> FD37 Audio channel 2, links from audio timer 1"
// "FD38 -> FD3F Audio channel 3, links trom audio timer 2"
switch (offset % 8)
{
case 0: // "8 bit. 2's Complement Volume Control"
channel.VolumeControl = (sbyte)value;
return;
case 1: // "Shift register feedback enable"
channel.FeedbackEnable.ByteData = value;
return;
case 2: // "Audio output value"
channel.OutputValue = (sbyte)value;
return;
case 3: // "Lower 8 Bits of Shift Register"
channel.LowerShiftRegister = value;
return;
case 4: // "Audio Timer Backup Value"
channel.BackupValue = value;
return;
case 5: // "Audio Control Bits"
//channel.AudioControl.ByteData = value;
AudioControlBits control = new AudioControlBits(value);
channel.AudioControl = control;
// "It is set on time out, reset with the reset timer done bit (xxx1, B6)"
if (control.ResetTimerDone)
{
channel.DynamicControlBits.TimerDone = false;
}
if (control.EnableCount || control.ResetTimerDone)
{
channel.Start(device.SystemClock.CompatibleCycleCount);
ForceTimerUpdate();
}
return;
case 6: // "Audio counter"
channel.CurrentValue = value;
ForceTimerUpdate();
return;
case 7: // "Other control bits"
channel.OtherControlBits = value;
return;
}
}
// Handle other addresses
switch (address)
{
case Mikey.Addresses.MSTEREO:
// "The Howard boards were not yet finished, so we went ahead and implemented this stereo on them.
// This form of stereo was channel switching controlled by FD50."
// TODO: Implement stereo
return;
case Mikey.Addresses.MPAN:
// TODO: Implement panning
return;
case Mikey.Addresses.INTRST:
// "Read is a poll, write will reset the int that corresponds to a set bit."
value ^= 0xff;
timerInterruptStatusRegister &= value;
// When timer interrupt status register is zero, IRQ line goes back up (not-active)
device.Cpu.SignalInterrupt(timerInterruptStatusRegister != 0 ? InterruptType.Irq : InterruptType.None);
ForceTimerUpdate();
return;
case Mikey.Addresses.INTSET:
// "Read is a poll, write will set the int that corresponds to a set bit."
timerInterruptStatusRegister |= value;
// When timer interrupt status register is zero, IRQ line goes back up (not-active)
device.Cpu.SignalInterrupt(timerInterruptStatusRegister != 0 ? InterruptType.Irq : InterruptType.None);
ForceTimerUpdate();
return;
case Mikey.Addresses.MIKEYSREV:
// "No actual register is implemented"
return;
// "Also note that only the lines that are set to input are actually valid for reading."
// "8 bits I/O direction corresponding to the 8 bits at FD8B 0=input, 1= output"
case Mikey.Addresses.IODIR:
IODIR.ByteData = value;
return;
// "Mikey Parallel Data(sort of a R/W) 8 bits of general purpose I/O data"
case Mikey.Addresses.IODAT:
IODAT.ByteData = value;
// "One is that it is the data pin for the shifter that holds the cartridge address."
device.Cartridge.CartAddressData(IODAT.CartAddressData);
// "The other is that it controls power to the cartridge."
device.CartridgePowerOn = !IODAT.CartPowerOff;
// "In its current use, it is the write enable line for writeable elements in the cartridge."
if (IODIR.AuxiliaryDigitalInOut == DataDirection.Output)
{
device.Cartridge.AuxiliaryDigitalInOut = IODAT.AuxiliaryDigitalInOut;
}
// "In its current use, it is the write enable line for writeable elements in the cartridge."
if (IODIR.AuxiliaryDigitalInOut == DataDirection.Output)
{
device.Cartridge.WriteEnabled = IODAT.AuxiliaryDigitalInOut;
}
return;
case Mikey.Addresses.SERCTL:
ComLynx.SERCTL = value;
return;
case Mikey.Addresses.SERDAT:
ComLynx.SERDAT = value;
return;
case Mikey.Addresses.SYSCTL1:
SYSCTL1.ByteData = value;
if (!SYSCTL1.Power)
{
device.Reset();
// TODO: Enter debug mode if configured
}
device.Cartridge.CartAddressStrobe(SYSCTL1.CartAddressStrobe);
return;
case Mikey.Addresses.SDONEACK:
// "Write a '00' to SDONEACK, allowing Mikey to respond to sleep commands."
// "The Suzy Done Acknowledge address must be written to prior to running the sprite engine.
// This is required even prior to the first time the sprite engine is activated.
// It it is not written to in the appropriate sequences, the CPU will not go to sleep
// when so requested. In addition, if some software accidentally allows a Suzy operation to
// complete without then following that completion with a write to SDONEACK, the CPU
// will not sleep. So if sprites stop working, something may have gone wrong with your
// SDONEACK software."
// TODO: Implement state for Suzy Done acknowledgement if necessary
return;
case Mikey.Addresses.CPUSLEEP:
// "A write of '0' to this address will reset the CPU bus request flip flop.
// The setting of the flip flop is described in the hardware specification."
// BUG: "Sleep does not work if Suzy does not have the bus."
// "We assume that everyone knows about this bug and behaves accordingly, so
// writing zero here must be to give Suzy access to the bus and it will start drawing
// sprites and will signal when it is done."
// This is implemented as a new wakeup time by calculating the number of cycles used
// and skipping forward in time to that moment.
ulong suzyCycles = device.Suzy.RenderSprites();
// TODO: For now use estimate of cycles for sprite drawing.
// Needs to be replaced with a better calculation. See also Handy PaintSprites code.
suzyCycles = 0; //1000;
device.Cpu.TrySleep(suzyCycles);
return;
case Mikey.Addresses.DISPCTL:
DISPCTL.ByteData = value;
return;
case Mikey.Addresses.PBKUP:
// "Additionally, the magic 'P' counter has to be set to match the LCD scan rate. The formula is:
// INT((((line time - .5us) / 15) * 4) -1)"
PBKUP = value;
return;
case Mikey.Addresses.DISPADRL:
// "DISPADRL (FD94) is lower 8 bits of display address with the bottom 2 bit ignored by the hardware.
// The address of the upper left corner of a display buffer must always have '00' in the bottom 2 bits."
VideoDisplayStartAddress.LowByte = (byte)(value & 0xFD);
return;
case Mikey.Addresses.DISPADRH:
// "DISPADRH (FD95) is upper 8 bits of display address."
VideoDisplayStartAddress.HighByte = value;
return;
case Mikey.Addresses.MAGRDY0:
case Mikey.Addresses.MAGRDY1:
case Mikey.Addresses.AUDIN:
case Mikey.Addresses.MIKEYHREV:
//Debug.WriteLineIf(GeneralSwitch.TraceWarning, String.Format("Mikey::Poke - Read-only address {0:X4} used (value {1:X2}).", address, value));
break;
default:
break;
}
if (address > Mikey.Addresses.BLUEREDF)
{
return;
}
// Blue and red color map
if (address >= Mikey.Addresses.BLUERED0 && address <= Mikey.Addresses.BLUEREDF)
{
int index = address - Mikey.Addresses.BLUERED0;
BlueRedColorMap[index] = value;
ArgbColorMap[index] &= 0xFF00FF00;
ArgbColorMap[index] |= (uint)((value & 0xF0) << 16); // Blue
ArgbColorMap[index] |= (uint)((value & 0x0F) << 4); // Red
return;
}
// Green color map
if (address >= Mikey.Addresses.GREEN0)
{
int index = address - Mikey.Addresses.GREEN0;
GreenColorMap[index] = value;
ArgbColorMap[index] &= 0xFFFF00FF;
ArgbColorMap[index] |= (uint)((value & 0x0F) << 12);
return;
}
if (address >= 0xFD20 && address <= 0xFD3F)
{
return;
}
//Trace.WriteLineIf(GeneralSwitch.TraceWarning, String.Format("Mikey::Poke: Unknown address ${0:X4} specified (value={1:X2}).", address,value));
}
public Timer(byte interruptMask)
: base()
{
InterruptMask = interruptMask;
StaticControlBits = new StaticControlBits(0);
}
