snes9x/obc1.cpp

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/*****************************************************************************\
Snes9x - Portable Super Nintendo Entertainment System (TM) emulator.
This file is licensed under the Snes9x License.
For further information, consult the LICENSE file in the root directory.
\*****************************************************************************/
2010-09-25 15:46:12 +00:00
#include "snes9x.h"
#include "memmap.h"
uint8 S9xGetOBC1 (uint16 Address)
{
switch (Address)
{
case 0x7ff0:
return (Memory.OBC1RAM[OBC1.basePtr + (OBC1.address << 2)]);
case 0x7ff1:
return (Memory.OBC1RAM[OBC1.basePtr + (OBC1.address << 2) + 1]);
case 0x7ff2:
return (Memory.OBC1RAM[OBC1.basePtr + (OBC1.address << 2) + 2]);
case 0x7ff3:
return (Memory.OBC1RAM[OBC1.basePtr + (OBC1.address << 2) + 3]);
case 0x7ff4:
return (Memory.OBC1RAM[OBC1.basePtr + (OBC1.address >> 2) + 0x200]);
}
return (Memory.OBC1RAM[Address - 0x6000]);
}
void S9xSetOBC1 (uint8 Byte, uint16 Address)
{
switch (Address)
{
case 0x7ff0:
Memory.OBC1RAM[OBC1.basePtr + (OBC1.address << 2)] = Byte;
break;
case 0x7ff1:
Memory.OBC1RAM[OBC1.basePtr + (OBC1.address << 2) + 1] = Byte;
break;
case 0x7ff2:
Memory.OBC1RAM[OBC1.basePtr + (OBC1.address << 2) + 2] = Byte;
break;
case 0x7ff3:
Memory.OBC1RAM[OBC1.basePtr + (OBC1.address << 2) + 3] = Byte;
break;
case 0x7ff4:
{
uint8 Temp;
Temp = Memory.OBC1RAM[OBC1.basePtr + (OBC1.address >> 2) + 0x200];
Temp = (Temp & ~(3 << OBC1.shift)) | ((Byte & 3) << OBC1.shift);
Memory.OBC1RAM[OBC1.basePtr + (OBC1.address >> 2) + 0x200] = Temp;
break;
}
case 0x7ff5:
if (Byte & 1)
OBC1.basePtr = 0x1800;
else
OBC1.basePtr = 0x1c00;
break;
case 0x7ff6:
OBC1.address = Byte & 0x7f;
OBC1.shift = (Byte & 3) << 1;
break;
}
Memory.OBC1RAM[Address - 0x6000] = Byte;
}
void S9xResetOBC1 (void)
{
for (int i = 0; i <= 0x1fff; i++)
Memory.OBC1RAM[i] = 0xff;
if (Memory.OBC1RAM[0x1ff5] & 1)
OBC1.basePtr = 0x1800;
else
OBC1.basePtr = 0x1c00;
OBC1.address = Memory.OBC1RAM[0x1ff6] & 0x7f;
OBC1.shift = (Memory.OBC1RAM[0x1ff6] & 3) << 1;
}
uint8 * S9xGetBasePointerOBC1 (uint16 Address)
{
if (Address >= 0x7ff0 && Address <= 0x7ff6)
return (NULL);
return (Memory.OBC1RAM - 0x6000);
}
uint8 * S9xGetMemPointerOBC1 (uint16 Address)
{
if (Address >= 0x7ff0 && Address <= 0x7ff6)
return (NULL);
return (Memory.OBC1RAM + Address - 0x6000);
}