mirror of https://github.com/stella-emu/stella.git
105 lines
2.6 KiB
C++
105 lines
2.6 KiB
C++
//============================================================================
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//
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// MM MM 6666 555555 0000 2222
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// MMMM MMMM 66 66 55 00 00 22 22
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// MM MMM MM 66 55 00 00 22
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// MM M MM 66666 55555 00 00 22222 -- "A 6502 Microprocessor Emulator"
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// MM MM 66 66 55 00 00 22
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// MM MM 66 66 55 55 00 00 22
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// MM MM 6666 5555 0000 222222
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//
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// Copyright (c) 1995-2010 by Bradford W. Mott and the Stella Team
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//
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// See the file "License.txt" for information on usage and redistribution of
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// this file, and for a DISCLAIMER OF ALL WARRANTIES.
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//
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// $Id$
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//============================================================================
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#ifndef NULLDEVICE_HXX
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#define NULLDEVICE_HXX
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class System;
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#include "bspf.hxx"
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#include "Device.hxx"
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/**
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Class that represents a "null" device. The basic idea is that a
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null device is installed in a 6502 based system anywhere there are
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holes in the address space (i.e. no real device attached).
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@author Bradford W. Mott
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@version $Id$
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*/
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class NullDevice : public Device
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{
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public:
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/**
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Create a new null device
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*/
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NullDevice();
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/**
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Destructor
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*/
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virtual ~NullDevice();
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public:
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/**
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Reset device to its power-on state
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*/
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void reset();
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/**
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Install device in the specified system. Invoked by the system
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when the device is attached to it.
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@param system The system the device should install itself in
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*/
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void install(System& system);
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/**
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Save the current state of this device to the given Serializer.
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@param out The Serializer object to use
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@return False on any errors, else true
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*/
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bool save(Serializer& out) const;
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/**
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Load the current state of this device from the given Serializer.
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@param in The Serializer object to use
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@return False on any errors, else true
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*/
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bool load(Serializer& in);
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/**
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Get a descriptor for the device name (used in error checking).
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@return The name of the object
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*/
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string name() const { return "NullDevice"; }
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public:
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/**
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Get the byte at the specified address
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@return The byte at the specified address
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*/
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uInt8 peek(uInt16 address);
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/**
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Change the byte at the specified address to the given value
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@param address The address where the value should be stored
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@param value The value to be stored at the address
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@return True if the poke changed the device address space, else false
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*/
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bool poke(uInt16 address, uInt8 value);
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};
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#endif
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