VRac/M6502/M6502.pm

package M6502;

use strict;
use warnings;

use Data::Dump qw/dump/;
use Carp qw/confess/;

=head1 NAME

M6502 - perl bindings for 6502 emulator

=cut

my $debug = 1;

our $VERSION = qw(0.0.1);

our @mem = (0xff) x 0x10000;    # 64M

# program counter
our $PC = 0xdd11;
# CPU registars
our ( $A, $P, $X, $Y, $S ) = (0) x 5;
# Set IPeriod to number of CPU cycles between calls to Loop6502
our $IPeriod = 1;

=head1 init

Called before C<Run6502>

=cut

sub init {
        my $self = shift;
        warn dump(@_);
        warn "inside init low-level M6502 from $self\n";
};

=head2 read

Read from memory

  $byte = read( $address );

=cut

sub read {
        my ($addr) = @_;
        my $byte = $mem[$addr];
        warn "# read(",dump(@_),") = ",dump( $byte ),"\n" if $debug;
        return $byte;
}

=head2 write

Write into emory

  write( $address, $byte );

=cut

sub write {
        warn "# write(",dump(@_),")\n" if $debug;
        my ($addr,$byte) = @_;
        $mem[$addr] = $byte;
}

=head2 poke_code

Write series of bytes into memory without passing through MMU

  $emu->poke_code( 0xbeef, 0xff, 0x00, 0xff, 0x00, 0xaa );

=cut

sub poke_code {
        my $self = shift;
        my $addr = shift;
        warn sprintf("# poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
        $mem[$addr++] = $_ foreach @_;
}

=head2 write_chunk

  $emu->write_chunk( $address, $chunk_of_data );

=cut

sub write_chunk {
        my ($self, $addr, $chunk) = @_;
        my $len = length($chunk);
        splice @mem, $addr, $len, unpack('C*', $chunk);
}

=head2 ram

Read searies of bytes from memory without passing through MMU

  $emu->ram( $from, $to );

=cut

sub ram {
        my $self = shift;
        my ($from,$to) = @_;
        if ($from + $to) {
                printf "ram %04x - %04x\n", $from, $to;
                return $mem[$from .. $to - 1];
        }
        printf "ram %04x\n", $from;
        return $mem[$from] if defined($from);
        confess "no from address";
}

1;
1	dpavlin	24	package M6502;
2
3			use strict;
4			use warnings;
5
6	dpavlin	27	use Data::Dump qw/dump/;
7	dpavlin	29	use Carp qw/confess/;
8	dpavlin	27
9	dpavlin	29	=head1 NAME
10	dpavlin	24
11	dpavlin	29	M6502 - perl bindings for 6502 emulator
12
13			=cut
14
15	dpavlin	27	my $debug = 1;
16	dpavlin	24
17	dpavlin	29	our $VERSION = qw(0.0.1);
18	dpavlin	27
19	dpavlin	29	our @mem = (0xff) x 0x10000; # 64M
20
21	dpavlin	25	# program counter
22	dpavlin	33	our $PC = 0xdd11;
23	dpavlin	25	# CPU registars
24			our ( $A, $P, $X, $Y, $S ) = (0) x 5;
25			# Set IPeriod to number of CPU cycles between calls to Loop6502
26	dpavlin	27	our $IPeriod = 1;
27	dpavlin	24
28	dpavlin	26	=head1 init
29
30			Called before C<Run6502>
31
32			=cut
33
34			sub init {
35	dpavlin	33	my $self = shift;
36			warn dump(@_);
37			warn "inside init low-level M6502 from $self\n";
38	dpavlin	26	};
39	dpavlin	27
40			=head2 read
41
42			Read from memory
43
44			$byte = read( $address );
45
46			=cut
47
48			sub read {
49			my ($addr) = @_;
50			my $byte = $mem[$addr];
51			warn "# read(",dump(@_),") = ",dump( $byte ),"\n" if $debug;
52			return $byte;
53			}
54
55			=head2 write
56
57			Write into emory
58
59			write( $address, $byte );
60
61			=cut
62
63			sub write {
64			warn "# write(",dump(@_),")\n" if $debug;
65			my ($addr,$byte) = @_;
66			$mem[$addr] = $byte;
67			}
68	dpavlin	29
69			=head2 poke_code
70
71			Write series of bytes into memory without passing through MMU
72
73			$emu->poke_code( 0xbeef, 0xff, 0x00, 0xff, 0x00, 0xaa );
74
75			=cut
76
77			sub poke_code {
78			my $self = shift;
79			my $addr = shift;
80			warn sprintf("# poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
81			$mem[$addr++] = $_ foreach @_;
82			}
83
84	dpavlin	31	=head2 write_chunk
85
86			$emu->write_chunk( $address, $chunk_of_data );
87
88			=cut
89
90			sub write_chunk {
91			my ($self, $addr, $chunk) = @_;
92			my $len = length($chunk);
93			splice @mem, $addr, $len, unpack('C*', $chunk);
94			}
95
96	dpavlin	29	=head2 ram
97
98			Read searies of bytes from memory without passing through MMU
99
100			$emu->ram( $from, $to );
101
102			=cut
103
104			sub ram {
105			my $self = shift;
106			my ($from,$to) = @_;
107			if ($from + $to) {
108	dpavlin	30	printf "ram %04x - %04x\n", $from, $to;
109	dpavlin	29	return $mem[$from .. $to - 1];
110			}
111	dpavlin	30	printf "ram %04x\n", $from;
112	dpavlin	29	return $mem[$from] if defined($from);
113			confess "no from address";
114			}
115
116	dpavlin	24	1;