/[VRac]/M6502/M6502.pm
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
ViewVC logotype

Diff of /M6502/M6502.pm

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 25 by dpavlin, Mon Jul 30 14:02:31 2007 UTC revision 50 by dpavlin, Tue Jul 31 11:14:19 2007 UTC
# Line 3  package M6502; Line 3  package M6502;
3  use strict;  use strict;
4  use warnings;  use warnings;
5    
6  # Dobrica Pavlinusic, <dpavlin@rot13.org> 07/30/07 13:23:19 CEST  use Data::Dump qw/dump/;
7  #  use Carp qw/confess/;
8  # Simple Orao emulation  use Exporter 'import';
9    our @EXPORT = qw'@mem $PC $A $P $X $Y $S $IPeriod $run_for $debug';
10    
11  my $mem = (0) x 0x10000;        # 64M  =head1 NAME
12    
13    M6502 - perl bindings for 6502 emulator
14    
15    =cut
16    
17    my $debug = 0;
18    
19    our $VERSION = qw(0.0.1);
20    
21    our @mem = (0xff) x 0x10000;    # 64M
22    
23  # program counter  # program counter
24  our $PC = 0xbeef;  our $PC = 0xbeef;
25  # CPU registars  # CPU registars
26  our ( $A, $P, $X, $Y, $S ) = (0) x 5;  our ( $A, $P, $X, $Y, $S ) = (0) x 5;
27  # Set IPeriod to number of CPU cycles between calls to Loop6502  # Set IPeriod to number of CPU cycles between calls to Loop6502
28  our $IPeriod = 20000;  our $IPeriod = 1;
29    # Exec6502 cycles
30    our $run_for = 0;
31    
32    =head1 init
33    
34    Called before C<Run6502>
35    
36    =cut
37    
38    sub init {
39            my $self = shift;
40            warn "inside init low-level M6502 from $self\n";
41    };
42    
43    =head2 read
44    
45    Read from memory
46    
47      $byte = read( $address );
48    
49    =cut
50    
51    sub read {
52            my ($addr) = @_;
53            my $byte = $mem[$addr];
54            warn "## M6502::read(",dump(@_),") = ",dump( $byte ),"\n" if $debug;
55            return $byte;
56    }
57    
58    =head2 write
59    
60    Write into emory
61    
62      write( $address, $byte );
63    
64    =cut
65    
66    sub write {
67            warn "## M6502::write(",dump(@_),")\n" if $debug;
68            my ($addr,$byte) = @_;
69            $mem[$addr] = $byte;
70    }
71    
72    =head2 poke_code
73    
74    Write series of bytes into memory passing through MMU (C<read> and C<write>)
75    functions. If you don't want to trigger MMU, use C<write_chunk>.
76    
77      $emu->poke_code( 0xbeef, 0xff, 0x00, 0xff, 0x00, 0xaa );
78    
79    =cut
80    
81    sub poke_code {
82            my $self = shift;
83            my $addr = shift;
84            warn sprintf("## M6502::poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
85            #$mem[$addr++] = $_ foreach @_;
86            $self->write($addr++, $_) foreach @_;
87    }
88    
89    =head2 write_chunk
90    
91    Low-level update of memory, overriding user specified MMU functions C<read> and C<write>
92    
93      $emu->write_chunk( $address, $chunk_of_data );
94    
95    =cut
96    
97    sub write_chunk {
98            my ($self, $addr, $chunk) = @_;
99            my $len = length($chunk);
100            splice @mem, $addr, $len, unpack('C*', $chunk);
101    }
102    
103    =head2 prompt
104    
105    Call this after C<< $run_for >> cycles have been run on processor
106    
107    =cut
108    
109    sub prompt {
110            warn "prompt -- you should override this\n";
111            return 1;
112    }
113    
114    =head2 push_R
115    
116    called by C<perl.c> to push changes in registars back to perl variables
117    
118    =cut
119    
120    sub push_R {
121            warn "## M6502::push_R(",dump(@_),")\n" if $debug;
122            my ( $a, $p, $x, $y, $s, $pc ) = @_;
123            $PC = $pc;
124            $S=$s; $X=$x; $Y=$y; $P=$p; $A=$a;
125            dump_R();
126    }
127    
128    =head2 dump_R
129    
130    helper function which dumps registers
131    
132    =cut
133    
134    sub dump_R {
135            warn sprintf("## M6502::dump_R PC: %04x A:%02x P:%02x X:%02x Y:%02x S:%02x\n", $PC, $A, $P, $X, $Y, $S) if $debug;
136    }
137    
138  1;  1;
Legend:
Removed from v.25  
changed lines
  Added in v.50
  ViewVC Help
Powered by ViewVC 1.1.26