BizHawk/BizHawk.Emulation.Cores/Consoles/Atari/A7800Hawk/Mappers/MapperDefault.cs

98 lines
2.1 KiB
C#

using BizHawk.Common;
using BizHawk.Common.NumberExtensions;
using System;
namespace BizHawk.Emulation.Cores.Atari.A7800Hawk
{
// Default mapper with no bank switching
// Just need to keep track of high score bios stuff
public class MapperDefault : MapperBase
{
public override byte ReadMemory(ushort addr)
{
if (addr >=0x1000 && addr < 0x1800)
{
//could be hsbios RAM here
if (Core._hsbios != null)
{
return Core._hsram[addr - 0x1000];
}
return 0xFF;
}
else if (addr < 0x4000)
{
// could be either RAM mirror or ROM
if (addr >= 0x3000 && Core._hsbios != null)
{
return Core._hsbios[addr - 0x3000];
}
else
{
return Core.RAM[0x800 + addr & 0x7FF];
}
}
else if (addr < 0x8000 && Core.is_pokey)
{
return Core.pokey.ReadReg(addr & 0xF);
}
else
{
// cartridge and other OPSYS
if ((Core._rom.Length >= 0x10000 - addr) && Core.A7800_control_register.Bit(2))
{
return Core._rom[Core._rom.Length - (0x10000 - addr)];
}
else if (addr >= (0x10000-Core._bios.Length) && !Core.A7800_control_register.Bit(2))
{
return Core._bios[addr - (0x10000 - Core._bios.Length)];
}
else
{
return 0x00;
}
}
}
public override byte PeekMemory(ushort addr)
{
return ReadMemory(addr);
}
public override void WriteMemory(ushort addr, byte value)
{
if (addr >= 0x1000 && addr < 0x1800)
{
//could be hsbios RAM here
if (Core._hsbios != null)
{
Core._hsram[addr - 0x1000] = value;
}
}
else if (addr < 0x4000)
{
// could be either RAM mirror or ROM
if (addr >= 0x3000 && Core._hsbios != null)
{
}
else
{
Core.RAM[0x800 + addr & 0x7FF] = value;
}
}
else if (addr < 0x8000 && Core.is_pokey)
{
Core.pokey.WriteReg(addr & 0xF, value);
}
else
{
// cartridge and other OPSYS
}
}
public override void PokeMemory(ushort addr, byte value)
{
WriteMemory(addr, value);
}
}
}