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added mirrors to 3E hotspots 

adapted derived 3E+ so that it does not use the mirrors
This commit is contained in:
thrust26 2025-02-08 20:28:22 +01:00
parent d4f3187ee0
commit acaeed8322
5 changed files with 86 additions and 56 deletions
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2
src/debugger/RiotDebug.cxx
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@ -159,7 +159,7 @@ uInt8 RiotDebug::inpt(int x)
static constexpr std::array<TIARegister, 6> _inpt = {
INPT0, INPT1, INPT2, INPT3, INPT4, INPT5
};
return mySystem.peekOob(_inpt[x]);
return mySystem.peekOob(_inpt[x] | 0x40); // fix for 3E/3F bankswitching
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

48
src/emucore/Cart3E.cxx
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@ -16,7 +16,6 @@
//============================================================================
#include "System.hxx"
#include "TIA.hxx"
#include "Cart3E.hxx"
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@ -37,54 +36,31 @@ void Cartridge3E::install(System& system)
{
CartridgeEnhanced::install(system);
const System::PageAccess access(this, System::PageAccessType::WRITE);
const System::PageAccess access(this, System::PageAccessType::READWRITE);
// The hotspots ($3E and $3F) are in TIA address space, so we claim it here
for(uInt16 addr = 0x00; addr < 0x40; addr += System::PAGE_SIZE)
// The hotspots ($3E and $3F) are in TIA address space (plus mirrors), so we claim them here
for(uInt16 addr = 0x0000; addr < 0x0800; addr += 0x100)
mySystem->setPageAccess(addr, access);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool Cartridge3E::checkSwitchBank(uInt16 address, uInt8 value)
{
// Tigervision bankswitching checks only A12, A11, A7, A6 and A0
address &= 0b1100011000001; // 0x18c1;
// Switch banks if necessary
if(address == 0x003F) {
// Switch ROM bank into segment 0
if(address == 0x01) // $3F
{
// Switch ROM bank into segment <value>
bank(value);
return true;
}
else if(address == 0x003E)
if(address == 0x00) // $3E
{
// Switch RAM bank into segment 0
// Switch RAM bank into segment <value>
bank(value + romBankCount());
return true;
}
return false;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
uInt8 Cartridge3E::peek(uInt16 address)
{
const uInt16 peekAddress = address;
address &= ROM_MASK;
if(address < 0x0040) // TIA access
return mySystem->tia().peek(address);
return CartridgeEnhanced::peek(peekAddress);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool Cartridge3E::poke(uInt16 address, uInt8 value)
{
const uInt16 pokeAddress = address;
address &= ROM_MASK;
if(address < 0x0040) // TIA access
{
checkSwitchBank(address, value);
return mySystem->tia().poke(address, value);
}
return CartridgeEnhanced::poke(pokeAddress, value);
}
}

24
src/emucore/Cart3E.hxx
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@ -45,7 +45,10 @@ class System;
To map ROM, the desired bank number of the first 2K segment is selected
by storing its value into $3F. To map RAM in the first 2K segment
instead, store the RAM bank number into $3E.
instead, store the RAM bank number into $3E. (*)
(*) 1/2025: Updated to emulate the new 3E board. Now reads and writes and
all mirror addresses are considered. This breaks previous Boulder Dash ROMs!
This implementation of 3E bankswitching numbers the RAM banks (up to 32)
after the ROM banks (up to 256).
@ -107,26 +110,11 @@ class Cartridge3E : public CartridgeEnhanced
}
#endif
public:
/**
Get the byte at the specified address
@return The byte at the specified address
*/
uInt8 peek(uInt16 address) override;
/**
Change the byte at the specified address to the given value
@param address The address where the value should be stored
@param value The value to be stored at the address
@return True if the poke changed the device address space, else false
*/
bool poke(uInt16 address, uInt8 value) override;
private:
bool checkSwitchBank(uInt16 address, uInt8 value) override;
uInt16 hotspot() const override { return 0x013F; } // mirrors outside ZP area
protected:
// log(ROM bank segment size) / log(2)
static constexpr uInt16 BANK_SHIFT = 11; // = 2K = 0x0800

41
src/emucore/Cart3EPlus.cxx
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@ -16,6 +16,7 @@
//============================================================================
#include "System.hxx"
#include "TIA.hxx"
#include "Cart3EPlus.hxx"
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@ -30,6 +31,17 @@ Cartridge3EPlus::Cartridge3EPlus(const ByteBuffer& image, size_t size,
myRamBankCount = RAM_BANKS;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void Cartridge3EPlus::install(System& system)
{
CartridgeEnhanced::install(system);
const System::PageAccess access(this, System::PageAccessType::WRITE);
// The hotspots ($3E and $3F) are in TIA address space, so we claim them here
for(uInt16 addr = 0x00; addr < 0x40; addr += System::PAGE_SIZE)
mySystem->setPageAccess(addr, access);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void Cartridge3EPlus::reset()
{
@ -50,7 +62,7 @@ bool Cartridge3EPlus::checkSwitchBank(uInt16 address, uInt8 value)
bank(value & 0b111111, value >> 6);
return true;
}
else if(address == 0x003E)
if(address == 0x003E)
{
// Switch RAM bank into segment
bank((value & 0b111111) + romBankCount(), value >> 6);
@ -58,3 +70,30 @@ bool Cartridge3EPlus::checkSwitchBank(uInt16 address, uInt8 value)
}
return false;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
uInt8 Cartridge3EPlus::peek(uInt16 address)
{
const uInt16 peekAddress = address;
address &= ROM_MASK;
if(address < 0x0040) // TIA access
return mySystem->tia().peek(address);
return CartridgeEnhanced::peek(peekAddress);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool Cartridge3EPlus::poke(uInt16 address, uInt8 value)
{
const uInt16 pokeAddress = address;
address &= ROM_MASK;
if(address < 0x0040) // TIA access
{
checkSwitchBank(address, value);
return mySystem->tia().poke(address, value);
}
return CartridgeEnhanced::poke(pokeAddress, value);
}

27
src/emucore/Cart3EPlus.hxx
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@ -102,6 +102,14 @@ class Cartridge3EPlus: public Cartridge3E
~Cartridge3EPlus() override = default;
public:
/**
Install cartridge in the specified system. Invoked by the system
when the cartridge is attached to it.
@param system The system the device should install itself in
*/
void install(System& system) override;
/** Reset device to its power-on state */
void reset() override;
@ -124,6 +132,23 @@ class Cartridge3EPlus: public Cartridge3E
}
#endif
public:
/**
Get the byte at the specified address
@return The byte at the specified address
*/
uInt8 peek(uInt16 address) override;
/**
Change the byte at the specified address to the given value
@param address The address where the value should be stored
@param value The value to be stored at the address
@return True if the poke changed the device address space, else false
*/
bool poke(uInt16 address, uInt8 value) override;
private:
/**
Checks if startup bank randomization is enabled. For this scheme,
@ -133,6 +158,8 @@ class Cartridge3EPlus: public Cartridge3E
bool checkSwitchBank(uInt16 address, uInt8 value) override;
uInt16 hotspot() const override { return 0x003F; }
/**
Get the number of segments supported by the cartridge.
*/