--- M6502/M6502.pm	2007/07/30 21:34:30	34
+++ M6502/M6502.pm	2007/07/31 17:15:54	68
@@ -6,15 +6,15 @@
 use Data::Dump qw/dump/;
 use Carp qw/confess/;
 use Exporter 'import';
-our @EXPORT = qw'@mem';
+our @EXPORT = qw'@mem $PC $A $P $X $Y $S $IPeriod $run_for $debug';
 
 =head1 NAME
 
-M6502 - perl bindings for 6502 emulator
+M6502 - perl bindings for M6502 CPU emulator
 
 =cut
 
-my $debug = 1;
+my $debug = 0;
 
 our $VERSION = qw(0.0.1);
 
@@ -23,11 +23,15 @@
 # program counter
 our $PC = 0xbeef;
 # CPU registars
-our ( $A, $P, $X, $Y, $S ) = (0x42) x 5;
+our ( $A, $P, $X, $Y, $S ) = (0) x 5;
 # Set IPeriod to number of CPU cycles between calls to Loop6502
 our $IPeriod = 1;
+# Exec6502 cycles
+our $run_for = 0;
 
-=head1 init
+=head1 FUNCTIONS
+
+=head2 init
 
 Called before C<Run6502>
 
@@ -35,7 +39,6 @@
 
 sub init {
 	my $self = shift;
-	warn dump(@_);
 	warn "inside init low-level M6502 from $self\n";
 };
 
@@ -50,7 +53,7 @@
 sub read {
 	my ($addr) = @_;
 	my $byte = $mem[$addr];
-	warn "# read(",dump(@_),") = ",dump( $byte ),"\n" if $debug;
+	warn "## M6502::read(",dump(@_),") = ",dump( $byte ),"\n" if $debug;
 	return $byte;
 }
 
@@ -63,14 +66,15 @@
 =cut
 
 sub write {
-	warn "# write(",dump(@_),")\n" if $debug;
+	warn "## M6502::write(",dump(@_),")\n" if $debug;
 	my ($addr,$byte) = @_;
 	$mem[$addr] = $byte;
 }
 
 =head2 poke_code
 
-Write series of bytes into memory without passing through MMU
+Write series of bytes into memory passing through MMU (C<read> and C<write>)
+functions. If you don't want to trigger MMU, use C<write_chunk>.
 
   $emu->poke_code( 0xbeef, 0xff, 0x00, 0xff, 0x00, 0xaa );
 
@@ -79,12 +83,31 @@
 sub poke_code {
 	my $self = shift;
 	my $addr = shift;
-	warn sprintf("# poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
-	$mem[$addr++] = $_ foreach @_;
+	warn sprintf("## M6502::poke_code(%04x,%s)\n", $addr, dump( @_ )) if $self->debug;
+	#$mem[$addr++] = $_ foreach @_;
+	# call low-level write
+	Arch::write($addr++, $_) foreach @_;
+}
+
+=head2 ram
+
+Read series of bytes into memory without MMU interaction
+
+  my @code = $emu->ram( 0xc000, 0xc1000 );
+
+=cut
+
+sub ram {
+	my $self = shift;
+	my ( $from, $to ) = @_;
+	warn sprintf("## M6502::ram(%04x,%04x)\n", $from, $to) if $self->debug;
+	return @mem[ $from .. $to ];
 }
 
 =head2 write_chunk
 
+Low-level update of memory, overriding user specified MMU functions C<read> and C<write>
+
   $emu->write_chunk( $address, $chunk_of_data );
 
 =cut
@@ -95,24 +118,59 @@
 	splice @mem, $addr, $len, unpack('C*', $chunk);
 }
 
-=head2 ram
+=head2 prompt
+
+Call this after C<< $run_for >> cycles have been run on processor
+
+=cut
+
+sub prompt {
+	warn "prompt -- you should override this\n";
+	return 1;
+}
 
-Read searies of bytes from memory without passing through MMU
+=head2 push_R
 
-  $emu->ram( $from, $to );
+called by C<perl.c> to push changes in registars back to perl variables
 
 =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";
+sub push_R {
+	warn "## M6502::push_R(",dump(@_),")\n" if $debug;
+	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 in humanly readable form
+
+  my $dump = dump_R;
+
+=cut
+
+sub dump_R {
+	my $dump = sprintf(" PC: %04x A:%02x P:%02x X:%02x Y:%02x S:%02x\n", $PC, $A, $P, $X, $Y, $S);
+	warn "## M6502::dump_R $dump" if $debug;
+	return $dump;
 }
 
+=head1 SEE ALSO
+
+L<Orao> is sample implementation using this module
+
+=head1 AUTHOR
+
+Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
+
+=head1 COPYRIGHT & LICENSE
+
+Copyright 2007 Dobrica Pavlinusic, All Rights Reserved.
+
+This program is free software; you can redistribute it and/or modify it
+under the same terms as Perl itself.
+
+=cut
 1;