IOMapper.cpp

/*****************************************************************************
*
* File: IOMapper.cpp
*
* Project: Osmose emulator.
*
* Description: This class will handle emulator input/output operation. 
*
* Author: Vedder Bruno
* Date: 08/10/2004, 18h00
*
* URL: http://bcz.emu-france.com/
*****************************************************************************/
#include "IOMapper.h"
#include "Bits.h"

/* Constructor need VDP reference */
IOMapper::IOMapper(VDP & v, SN76489 & p) : vdp( v ), psg( p )
{
    reset();
}

/*----------------------------------------------------------------------*/
/* This method resets ports.						*/
/*----------------------------------------------------------------------*/
void IOMapper::reset()
{
    if (opt.inputType == DEFAULT_PAD)
    {
        port3F = 0xFF;	// Active low      
    }
    else
    if	 (opt.inputType == PADDLE)
    {
        port3F = 0x30;	// 00110000b
    }
    port3E = 0xA4;
    portPAD1 = 0xFF;
    portPAD2 = 0xFF;
    paddleValue = 0;
    flipFlop = false;
}	 


/*----------------------------------------------------------------------*/
/* Based on Charles MacDonald documentation, this method dispatches	*/
/* port write, depending on A7, A6 and A0 address line.			*/
/*----------------------------------------------------------------------*/
void IOMapper::out8(unsigned port, unsigned char value)
{
   if (port <= 0x3F)
   {
       if (port & BIT0)  // Write to port 3F
       {
#ifdef AUTO_NAT_VERBOSE
	   cout << "AUTO_NAT port 0x3F written with value " << hex << setw(2) << setfill('0') << (int)value << endl;
#endif

	   port3F = value;
	   if ( (port3F & BIT0) && (port3F & BIT2) )
	   {
#ifdef AUTO_NAT_VERBOSE
               cout << "Auto nationalisation asked." << endl;
#endif
	       if (opt.WorldVersion == EXPORT)
	       {
		   // Copy 3F bit7 to DD bit7
		   if (port3F & BIT7)
		   {
        	       portPAD2 |= BIT7; 
		   }
		   else
		   {
        	       portPAD2 &= (0x7F);
		   }
		   // Copy 3F bit5 to DD bit6	   
		   if (port3F & BIT5)
		   {
        	       portPAD2 |= BIT6;
		   }
		   else
		   {
        	       portPAD2 &= 0xBF;
		   }
	       }
	       else
	       {
        	   portPAD2 &= 0x3F;
	       }       

	       if ( ((value & BIT0) && (value & BIT2))== 0 )
	       {
	#ifdef AUTO_NAT_VERBOSE
	       cout << "Auto nationalisation reset asked." << endl;
	#endif
	       }
	   }
	   if (port3F & BIT5)
	   {
	      // cout << "Selecting X7-X4 value on DC" << endl;
	   }  
	   else
	   {
	      // cout << "Selecting X3-X0 value on DC" << endl;
	   }
	   return;           
       }
       else  // Write to port 3E
       {
#ifdef MEM_CTRL_VERBOSE
           cout << "MEM CTRL port 0x3E written with value " << hex << setw(2) << setfill('0') << (int)value << endl;
#endif
           port3E = value;     
#ifdef MEM_CTRL_VERBOSE
	   if (value & BIT2)
	   {
        	cout << "I/O chip Disable." << endl;
	   }
	   else
	   {
        	cout << "I/O chip Enabled." << endl;       
	   }

	   if (value & BIT3)
	   {
        	cout << "BIOS ROM Disable." << endl;
	   }
	   else
	   {
        	cout << "BIOS ROM Enabled." << endl;       
	   }

	   if (value & BIT4)
	   {
        	cout << "Work Ram Disable (For battery backed RAM ?)." << endl;
	   }
	   else
	   {
        	cout << "Work Ram Enable." << endl;
	   }

	   if (value & BIT5)
	   {
               cout << "Card slot Disable." << endl;
	   }
	   else
	   {
               cout << "Card slot Enable." << endl;
	   }

	   if (value & BIT6)
	   {
               cout << "Cartridge slot Disable." << endl;
	   }
	   else
	   {
               cout << "Cartridge slot Enable." << endl;
	   }
	   if (value & BIT7)
	   {
               cout << "Expansion slot Disable." << endl;
	   }
	   else
	   {
               cout << "Expansion slot Enable." << endl;
	   }
#endif       
       return;
       }
   } 

   if (port <= 0x7F)
   {
       psg.writePort(value);
       return;
#ifdef PSG_VERBOSE
       cout << "PSG port 0x7F written with value " << hex << setw(2) << setfill('0') << (int)value << endl;
#endif
       return;
   }

   if (port <= 0xBF)
   {
       if (port & BIT0) // Write on VDP Ctrl Port 0xBF
       {
#ifdef VDP_ACCESS
	   cout << "VDP_CTRL port 0xBF written with value " << hex << setw(2) << setfill('0') << (int)value << endl;
#endif
	   vdp.writeCtrlPort( value );
	   return;
       }
       else		// Write on VDP Data Port 0xBE
       {
#ifdef VDP_VERBOSE
           cout << "VDP_DATA port 0xBE written with value " << hex << setw(2) << setfill('0') << (int)value << endl;
#endif
           vdp.writeDataPort( value );
           return;
       }
   }
#ifdef VDP_VERBOSE
       cout << "Unkown port "<< hex << setw(2) << setfill('0') << (int)port << " written with value " << hex << setw(2) << setfill('0') << (int)value << endl;
#endif

}

/*----------------------------------------------------------------------*/
/* Based on Charles MacDonald documentation, this method dispatches	*/
/* port read, depending on A7, A6 and A0 address line.			*/
/*----------------------------------------------------------------------*/
unsigned char IOMapper::in8(unsigned port)
{
	if (port == 0x3E)
	{
	    return port3E;
	    //cout << "MEM CTRL Port 0x3E: Read, value is " << hex << setw(2) << setfill('0') << (int)port3E << endl;
	}
    if (port <= 0x3F)
    {
		//cout << "NOT IMPLEMENTED / EXPERIMENTAL: Read port <=0x3f" << endl;
        return (port & 0xff);
    }
    
    if (port <= 0x7F)
    {
        if (port & BIT0) 	// Read H counter port.
		{
//#ifdef VDP_VERBOSE
           cout << "NOT IMPLEMENTED: VDP port H COUTNER 0x7F read."<< endl;
//#endif
	    return 0xFF;
		}
		else 			// Read on VDP Vertical counter
		{
#ifdef VDP_VERBOSE
           cout << "VDP, port V COUTNER 0x7E read."<< endl;
#endif
            return vdp.v_counter;	    
		}
    }

    if (port <= 0xBF)		// Read VDP status flag
    {
        if (port & BIT0)
	{
#ifdef VDP_VERBOSE
	   cout << "VDP status read."<< endl;
#endif
            return vdp.readStatusFlag();	
	}
	else			// Read VDP Data port
	{
#ifdef VDP_VERBOSE
           cout << "CRAM/VRAM read."<< endl;
#endif
	    return vdp.readDataPort();
	}
    }

    // Port is > 0xBF and < 0xFF
    if (port & BIT0)
    {
#ifdef PAD_VERBOSE
       cout << "Port PAD2 0xDD read."<< endl;
#endif
        return portPAD2;
    }
    else
    {
#ifdef PAD_VERBOSE
        cout << "Port PAD1 0xDC read."<< endl;
#endif
        if (opt.inputType == PADDLE) 
	{
	    flipFlop^=1;
	    if (flipFlop == true)
	    {
	        portPAD1 |= BIT5;
		portPAD1 &= 0xf0;
		portPAD1 |= (paddleValue >> 4);
	    }
	    else
	    {
	        portPAD1 &= ~BIT5;
		portPAD1 &= 0xf0;
		portPAD1 |= (paddleValue & 0x0f);
	    }
	}
	return portPAD1;
    }
    cout << "Unkown port "<< hex << setw(2) << setfill('0') << (int)port << " read."<< endl;
}