mirror of https://github.com/stella-emu/stella.git
151 lines
4.2 KiB
C++
151 lines
4.2 KiB
C++
//============================================================================
|
|
//
|
|
// SSSS tt lll lll
|
|
// SS SS tt ll ll
|
|
// SS tttttt eeee ll ll aaaa
|
|
// SSSS tt ee ee ll ll aa
|
|
// SS tt eeeeee ll ll aaaaa -- "An Atari 2600 VCS Emulator"
|
|
// SS SS tt ee ll ll aa aa
|
|
// SSSS ttt eeeee llll llll aaaaa
|
|
//
|
|
// Copyright (c) 1995-2017 by Bradford W. Mott, Stephen Anthony
|
|
// and the Stella Team
|
|
//
|
|
// See the file "License.txt" for information on usage and redistribution of
|
|
// this file, and for a DISCLAIMER OF ALL WARRANTIES.
|
|
//============================================================================
|
|
|
|
#include "System.hxx"
|
|
#include "Cart4KSC.hxx"
|
|
|
|
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
Cartridge4KSC::Cartridge4KSC(const BytePtr& image, uInt32 size,
|
|
const Settings& settings)
|
|
: Cartridge(settings)
|
|
{
|
|
// Copy the ROM image into my buffer
|
|
memcpy(myImage, image.get(), std::min(4096u, size));
|
|
createCodeAccessBase(4096);
|
|
}
|
|
|
|
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
void Cartridge4KSC::reset()
|
|
{
|
|
initializeRAM(myRAM, 128);
|
|
|
|
myBankChanged = true;
|
|
}
|
|
|
|
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
void Cartridge4KSC::install(System& system)
|
|
{
|
|
mySystem = &system;
|
|
|
|
System::PageAccess access(this, System::PA_READ);
|
|
|
|
// Set the page accessing method for the RAM writing pages
|
|
access.type = System::PA_WRITE;
|
|
for(uInt32 j = 0x1000; j < 0x1080; j += (1 << System::PAGE_SHIFT))
|
|
{
|
|
access.directPokeBase = &myRAM[j & 0x007F];
|
|
access.codeAccessBase = &myCodeAccessBase[j & 0x007F];
|
|
mySystem->setPageAccess(j >> System::PAGE_SHIFT, access);
|
|
}
|
|
|
|
// Set the page accessing method for the RAM reading pages
|
|
access.directPokeBase = 0;
|
|
access.type = System::PA_READ;
|
|
for(uInt32 k = 0x1080; k < 0x1100; k += (1 << System::PAGE_SHIFT))
|
|
{
|
|
access.directPeekBase = &myRAM[k & 0x007F];
|
|
access.codeAccessBase = &myCodeAccessBase[0x80 + (k & 0x007F)];
|
|
mySystem->setPageAccess(k >> System::PAGE_SHIFT, access);
|
|
}
|
|
|
|
// Map ROM image into the system
|
|
for(uInt32 address = 0x1100; address < 0x2000; address += (1 << System::PAGE_SHIFT))
|
|
{
|
|
access.directPeekBase = &myImage[address & 0x0FFF];
|
|
access.codeAccessBase = &myCodeAccessBase[address & 0x0FFF];
|
|
mySystem->setPageAccess(address >> System::PAGE_SHIFT, access);
|
|
}
|
|
}
|
|
|
|
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
uInt8 Cartridge4KSC::peek(uInt16 address)
|
|
{
|
|
// The only way we can get to this method is if we attempt to read from
|
|
// the write port (0xF000 - 0xF080, 128 bytes), in which case an
|
|
// unwanted write is triggered
|
|
uInt8 value = mySystem->getDataBusState(0xFF);
|
|
|
|
if(bankLocked())
|
|
return value;
|
|
else
|
|
{
|
|
triggerReadFromWritePort(address);
|
|
return myRAM[address & 0x0FFF] = value;
|
|
}
|
|
}
|
|
|
|
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
bool Cartridge4KSC::patch(uInt16 address, uInt8 value)
|
|
{
|
|
address &= 0x0FFF;
|
|
|
|
if(address < 0x0100)
|
|
{
|
|
// Normally, a write to the read port won't do anything
|
|
// However, the patch command is special in that ignores such
|
|
// cart restrictions
|
|
myRAM[address & 0x007F] = value;
|
|
}
|
|
else
|
|
myImage[address & 0xFFF] = value;
|
|
|
|
return myBankChanged = true;
|
|
}
|
|
|
|
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
const uInt8* Cartridge4KSC::getImage(uInt32& size) const
|
|
{
|
|
size = 4096;
|
|
return myImage;
|
|
}
|
|
|
|
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
bool Cartridge4KSC::save(Serializer& out) const
|
|
{
|
|
try
|
|
{
|
|
out.putString(name());
|
|
out.putByteArray(myRAM, 128);
|
|
}
|
|
catch(...)
|
|
{
|
|
cerr << "ERROR: Cartridge4KSC::save" << endl;
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
bool Cartridge4KSC::load(Serializer& in)
|
|
{
|
|
try
|
|
{
|
|
if(in.getString() != name())
|
|
return false;
|
|
|
|
in.getByteArray(myRAM, 128);
|
|
}
|
|
catch(...)
|
|
{
|
|
cerr << "ERROR: Cartridge4KSC::load" << endl;
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|