Games::NES::Emulator - An object-oriented NES (6502) emulator

Games-NES-Emulator documentation

Contained in the Games-NES-Emulator distribution.

Index

Code Index:

package Games::NES::Emulator
- new
- load_rom
- run
EOF

NAME

Games::NES::Emulator - An object-oriented NES (6502) emulator

SYNOPSIS

    use Games::NES::Emulator;

    my $emu = Games::NES::Emulator->new;
    $emu->load_rom( 'mario.nes' );
    $emu->run;

WARNING

Don't get too excited -- this code doesn't really do anything yet. Don't complain to me that "Blaster Master" isn't working. It's not ready yet.

DESCRIPTION

Games::Emulator::NES contains a set of modules to emulate a classic NES gaming machine.

RATIONALE

I've always been interested in hardware emulation. I grew up playing the NES, so I figured it would be a decent place to start. Over the last year I've written some (non-functioning) code based on some freely available emulators on the web. Hopefully by putting the skeleton of the code online, it will spur me on to continue the development.

As for choosing Perl for the emulation language, Perl is what I'm most comfortable with, and I don't particularly care about speed -- yet. Perhaps some bits can be rewritten in XS, but I'll cross that bridge when i get to it.

METHODS

new( )

Create a new instance of the emulator. Initializes the CPU.

load_rom( $filename )

Loads the rom from $filename.

run( )

Begins execution of the code found in the ROM.

AUTHOR

Brian Cassidy <bricas@cpan.org>

COPYRIGHT AND LICENSE

Copyright 2007 by Brian Cassidy

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

* Games::NES::ROM
* Games::NES::Emulator::CPU
* Games::NES::Emulator::APU
* Games::NES::Emulator::PPU

Games-NES-Emulator documentation

Contained in the Games-NES-Emulator distribution.

package Games::NES::Emulator;

use strict;
use warnings;

use base qw( Class::Accessor::Fast );

use Games::NES::ROM; # the game
use Games::NES::Emulator::CPU; # NES specific 6502 CPU
use Games::NES::Emulator::PPU; # graphics
use Games::NES::Emulator::APU; # audio
use Games::NES::Emulator::Input; # controller

our $VERSION = '0.03';

__PACKAGE__->mk_accessors( qw( rom cpu apu ppu mapper inputs running ) );

sub new {
    my $class = shift;
    my $self  = $class->SUPER::new( @_ );

    $self->cpu( Games::NES::Emulator::CPU->new )->init( $self );
    $self->ppu( Games::NES::Emulator::PPU->new )->init( $self );
    $self->apu( Games::NES::Emulator::APU->new )->init( $self );

    $self->inputs( [
        Games::NES::Emulator::Input->new( { number => 1 } ),
        Games::NES::Emulator::Input->new( { number => 2 } )
    ] );

    return $self;
}

sub load_rom {
    my $self     = shift;
    my $filename = shift;

    $self->rom( Games::NES::ROM->new( $filename ) );

    my $mapperid = $self->rom->mapper;

    my $class = "Games::NES::Emulator::Mappers::Mapper${mapperid}";
    eval "use $class";

    if( $@ ) {
        die "Mapper $mapperid not supported.";
    }

    $self->mapper( $class->new )->init( $self );
    $self->cpu->interrupt_line( $self->cpu->interrupt_line | $self->cpu->RESET );
}

sub run {
    my $self = shift;
    die 'No ROM loaded.' unless $self->rom;

    $self->running( 1 );

    while( $self->running ) {
        print $self->cpu->debug;
        <STDIN>;
        $self->cpu->execute_instruction;
    }
}

1;