--- M6502/M6502.pm	2007/07/30 14:23:22	26
+++ M6502/M6502.pm	2007/07/31 08:41:06	40
@@ -3,18 +3,32 @@
 use strict;
 use warnings;
 
-# Dobrica Pavlinusic, <dpavlin@rot13.org> 07/30/07 13:23:19 CEST
-#
-# Simple Orao emulation
+use Data::Dump qw/dump/;
+use Carp qw/confess/;
+use Exporter 'import';
+our @EXPORT = qw'@mem $PC $A $P $X $Y $S $IPeriod $run_for';
 
-my $mem = (0) x 0x10000;	# 64M
+=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 = 0xbeef;
 # CPU registars
 our ( $A, $P, $X, $Y, $S ) = (0) x 5;
 # Set IPeriod to number of CPU cycles between calls to Loop6502
-our $IPeriod = 20000;
+our $IPeriod = 1;
+# Exec6502 cycles
+our $run_for = 1;
+$run_for = 0x42;
 
 =head1 init
 
@@ -23,7 +37,110 @@
 =cut
 
 sub init {
-	warn "inside init\n";
-	print "stdout\n";
+	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,$to) = @_;
+	warn "ram($from,$to)\n";
+	if ($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";
+}
+
+=head2 push_R
+
+called by C<perl.c> to push changes in registars back to perl variables
+
+=cut
+
+sub push_R {
+	warn "push_R(",dump(@_),")\n";
+	my ( $a, $p, $x, $y, $s, $pc ) = @_;
+	$PC = $pc;
+	$S=$s; $X=$x; $Y=$y; $P=$p; $A=$a;
+	dump_R();
+}
+
+=head2 dump_R
+
+helper function which dumps registers
+
+=cut
+
+sub dump_R {
+	warn sprintf("PC: %04x A:%02x P:%02x X:%02x Y:%02x S:%02x\n", $PC, $A, $P, $X, $Y, $S);
+}
+
 1;