stella/src/emucore/Cart3F.hxx

//============================================================================
//
//   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) 1995-2018 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.
//============================================================================

#ifndef CARTRIDGE3F_HXX
#define CARTRIDGE3F_HXX

class System;

#include "bspf.hxx"
#include "Cart.hxx"
#ifdef DEBUGGER_SUPPORT
  #include "Cart3FWidget.hxx"
#endif

/**
  This is the cartridge class for Tigervision's bankswitched
  games.  In this bankswitching scheme the 2600's 4K cartridge
  address space is broken into two 2K segments.  The last 2K
  segment always points to the last 2K of the ROM image.  The
  desired bank number of the first 2K segment is selected by
  storing its value into $3F.  Actually, any write to location
  $00 to $3F will change banks.  Although, the Tigervision games
  only used 8K this bankswitching scheme supports up to 512K.

  @author  Bradford W. Mott
*/
class Cartridge3F : public Cartridge
{
  friend class Cartridge3FWidget;

  public:
    /**
      Create a new cartridge using the specified image and size

      @param image     Pointer to the ROM image
      @param size      The size of the ROM image
      @param settings  A reference to the various settings (read-only)
    */
    Cartridge3F(const BytePtr& image, uInt32 size, const Settings& settings);
    virtual ~Cartridge3F() = default;

  public:
    /**
      Reset device to its power-on state
    */
    void reset() override;

    /**
      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;

    /**
      Install pages for the specified bank in the system.

      @param bank The bank that should be installed in the system
    */
    bool bank(uInt16 bank) override;

    /**
      Get the current bank.
    */
    uInt16 getBank() const override;

    /**
      Query the number of banks supported by the cartridge.
    */
    uInt16 bankCount() const override;

    /**
      Patch the cartridge ROM.

      @param address  The ROM address to patch
      @param value    The value to place into the address
      @return    Success or failure of the patch operation
    */
    bool patch(uInt16 address, uInt8 value) override;

    /**
      Access the internal ROM image for this cartridge.

      @param size  Set to the size of the internal ROM image data
      @return  A pointer to the internal ROM image data
    */
    const uInt8* getImage(uInt32& size) const override;

    /**
      Save the current state of this cart to the given Serializer.

      @param out  The Serializer object to use
      @return  False on any errors, else true
    */
    bool save(Serializer& out) const override;

    /**
      Load the current state of this cart from the given Serializer.

      @param in  The Serializer object to use
      @return  False on any errors, else true
    */
    bool load(Serializer& in) override;

    /**
      Get a descriptor for the device name (used in error checking).

      @return The name of the object
    */
    string name() const override { return "Cartridge3F"; }

  #ifdef DEBUGGER_SUPPORT
    /**
      Get debugger widget responsible for accessing the inner workings
      of the cart.
    */
    CartDebugWidget* debugWidget(GuiObject* boss, const GUI::Font& lfont,
        const GUI::Font& nfont, int x, int y, int w, int h) override
    {
      return new Cartridge3FWidget(boss, lfont, nfont, x, y, w, h, *this);
    }
  #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:
    // Pointer to a dynamically allocated ROM image of the cartridge
    BytePtr myImage;

    // Size of the ROM image
    uInt32 mySize;

    // Indicates which bank is currently active for the first segment
    uInt16 myCurrentBank;

  private:
    // Following constructors and assignment operators not supported
    Cartridge3F() = delete;
    Cartridge3F(const Cartridge3F&) = delete;
    Cartridge3F(Cartridge3F&&) = delete;
    Cartridge3F& operator=(const Cartridge3F&) = delete;
    Cartridge3F& operator=(Cartridge3F&&) = delete;
};

#endif