public void Reset()
{
this._interruptMessage = 0xffff;
this._deviceFlags = DeviceFlagBits.NONE;
this._lastInterruptType = InterruptType.NONE;
this._currentOperation = OperationType.None;
this._currentSector = 0;
this._sectorsRemaining = 0;
this._currentHeadSector = 0;
this._currentMemoryAddress = 0x0000;
}
public void Interrupt(out int additionalCycles)
{
// default to 0 cycles
additionalCycles = 0;
var msg = (InterruptMessage)this._system.Cpu.Registers[0];
var param = this._system.Cpu.Registers[1];
switch (msg)
{
case InterruptMessage.QUERY_MEDIA_PRESENT:
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NONE;
this._system.Cpu.Registers[1] = this._currentDisk != null ? (ushort)1 : (ushort)0;
break;
case InterruptMessage.QUERY_MEDIA_PARAMETERS:
if (this._currentDisk == null)
{
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NO_MEDIA;
break;
}
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NONE;
this._system.Cpu.Registers[1] = (ushort)this._currentDisk.WordsPerSector;
this._system.Cpu.Registers[2] = (ushort)this._currentDisk.NumSectors;
this._system.Cpu.Registers[3] = this._currentDisk.WriteLocked ? (ushort)1 : (ushort)0;
break;
case InterruptMessage.QUERY_DEVICE_FLAGS:
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NONE;
this._system.Cpu.Registers[1] = (ushort)this._deviceFlags;
break;
case InterruptMessage.UPDATE_DEVICE_FLAGS:
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NONE;
this._deviceFlags = (DeviceFlagBits)this._system.Cpu.Registers[1];
break;
case InterruptMessage.QUERY_INTERRUPT_TYPE:
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NONE;
this._system.Cpu.Registers[1] = (ushort)this._lastInterruptType;
break;
case InterruptMessage.SET_INTERRUPT_MESSAGE:
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NONE;
this._interruptMessage = this._system.Cpu.Registers[1];
break;
case InterruptMessage.READ_SECTORS:
if (this._currentDisk == null)
{
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NO_MEDIA;
break;
}
if (this._currentOperation != OperationType.None)
{
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_PENDING;
break;
}
if (param >= this._currentDisk.NumSectors || param + this._system.Cpu.Registers[2] > this._currentDisk.NumSectors)
{
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_INVALID_SECTOR;
break;
}
this._currentOperation = OperationType.Read;
this._currentSector = param;
this._sectorsRemaining = this._system.Cpu.Registers[2];
this._currentMemoryAddress = this._system.Cpu.Registers[3];
if (!this.NonBlockingFlag) this._system.BlockExecution(true);
QueueNextStep();
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NONE;
break;
case InterruptMessage.WRITE_SECTORS:
if (this._currentDisk == null)
{
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NO_MEDIA;
break;
}
if (this._currentOperation != OperationType.None)
{
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_PENDING;
break;
}
if (param >= this._currentDisk.NumSectors || param + this._system.Cpu.Registers[2] > this._currentDisk.NumSectors)
{
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_INVALID_SECTOR;
break;
}
this._currentOperation = OperationType.Write;
this._currentSector = param;
this._sectorsRemaining = this._system.Cpu.Registers[2];
this._currentMemoryAddress = this._system.Cpu.Registers[3];
if (!this.NonBlockingFlag) this._system.BlockExecution(true);
QueueNextStep();
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NONE;
break;
case InterruptMessage.QUERY_MEDIA_QUALITY:
if (this._currentDisk == null)
{
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NO_MEDIA;
break;
}
this._system.Cpu.Registers[0] = (ushort)ErrorCode.ERROR_NONE;
this._system.Cpu.Registers[1] = (ushort)this._currentDisk.MediaType;
break;
}
}