diff --git a/.gitignore b/.gitignore
index cea93ba..e1b9452 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,2 @@
-.*
-!.gitignore
 apple1emu.dsk
+apple1emu.sym
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..1aff950
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,16 @@
+DISK=apple1emu.dsk
+ROMS=apple1.rom applesoft-lite-0.4-ram.bin ehbasic.bin 65C02.rom.bin applesoft-lite-0.4.bin
+
+.PHONY: clean
+
+$(DISK): apple1emu.asm font.bin opdefs.inc $(ROMS)
+	pyz80.py --exportfile=apple1emu.sym apple1emu.asm
+
+font.bin: font.png png2bin.pl
+	./png2bin.pl font.png 6 8
+
+opdefs.inc: opdefs.pl opimpl.inc apple1emu.asm
+	./opdefs.pl
+
+clean:
+	rm -f $(DISK) apple1emu.sym
diff --git a/font.pl b/font.pl
deleted file mode 100755
index 276cbd0..0000000
--- a/font.pl
+++ /dev/null
@@ -1,64 +0,0 @@
-#!/usr/bin/perl -w
-#
-# Convert PNG image to raw font binary for Apple 1 emulator
-#
-# Makes lots of assumptions about the input image!
-
-use Compress::Zlib;
-
-# Input image and output data file
-my $input = 'font.png';
-my $output = 'font.bin';
-
-# Our characters are 6 pixels wide
-$chrw = 6;
-
-
-# Slurp the entire PNG image
-open INPUT, "<$input" and binmode INPUT or die "$input: $!\n";
-read INPUT, $data='', -s $input;
-close INPUT;
-
-# Find and extract the image dimensions
-$data =~ /IHDR(.{8})/s;
-($w,$h) = unpack "N2", $1;
-
-# Extract and expand the compressed image data
-($data) = $data =~ /IDAT(.*).{8}IEND/s;
-$data = Compress::Zlib::uncompress($data);
-
-# Remove the type byte from the start of each line
-$w_2 = $w/2;
-$data =~ s/.(.{$w_2})/$1/sg;
-
-@data = ();
-
-# Unpack the pixel nibbles
-foreach (unpack "C*", $data) {
-  push @data, $_>>4, $_&1;
-}
-
-
-open OUTPUT, ">$output" and binmode OUTPUT or die "$output: $!\n";
-
-# Process all characters
-foreach $chr (0..$w/$chrw-1)
-{
-  # Process the image line by line
-  foreach $y (0..$h-1)
-  {
-    # Locate the pixel data for the current character
-    my $x = $chr*$chrw + $w*$y;
-    my $b = 0;
-
-    # Pack the 1bpp data into a single byte
-    foreach (@data[$x..$x+$chrw-1]) {
-      $b = ($b << 1) | $_;
-    }
-
-    # Left-align within the byte and output it
-    print OUTPUT chr($b << (8-$chrw));
-  }
-}
-
-close OUTPUT;
diff --git a/make.bat b/make.bat
new file mode 100755
index 0000000..612a91a
--- /dev/null
+++ b/make.bat
@@ -0,0 +1,12 @@
+@echo off
+
+if "%1"=="clean" goto clean
+
+opimpl.pl
+pyz80.py --exportfile=apple1emu.sym apple1emu.asm
+goto end
+
+:clean
+if exist apple1emu.dsk del apple1emu.dsk apple1emu.sym
+
+:end
diff --git a/opdefs.pl b/opdefs.pl
index 703194c..e2e73ef 100755
--- a/opdefs.pl
+++ b/opdefs.pl
@@ -1,10 +1,11 @@
 #!/usr/bin/perl -w
 #
 # Calculates opcode addresses for the inline instruction decoding table
-#
-# Used by the Apple 1 emulator, available from:
-#
-#     http://simonowen.com/sam/apple1emu/
+
+# Allow -v option for verbose output
+use Getopt::Std;
+$opt_v = 0;
+getopts('v');
 
 $source = 'apple1emu.asm';
 $codeend = 0xd000;
@@ -75,7 +76,7 @@ MSB:
 # Position base so code finishes at the required point
 $base = $codeend - (($size + 0xff) & ~0xff);
 
-print "Size = $size, used = $used, slack = ", $size-$used, "\n";
+print "Size = $size, used = $used, slack = ", $size-$used, "\n" unless !$opt_v;
 
 # Output sorted list of calculated positions
 foreach (sort { $a <=> $b } @todo) {
diff --git a/png2bin.pl b/png2bin.pl
new file mode 100755
index 0000000..4cb5a35
--- /dev/null
+++ b/png2bin.pl
@@ -0,0 +1,89 @@
+#!/usr/bin/perl -w
+#
+# Convert PNG image to Spectrum format sprite image data
+#
+# Input image should be palettised 1-bit with no transparency
+#
+# Simon Owen <simon@simonowen.com>
+
+use Compress::Zlib;
+use Getopt::Std;
+
+# Allow -v option for verbose output
+getopts('v');
+
+# Strip path from input filename, and check 
+$0 =~ s/.*\///;
+die "Usage: $0 <image> <sprite-width> [<sprite-height>]\n" unless @ARGV == 2 or @ARGV == 3;
+
+# Input image and output data file
+($file,$w,$h) = (@ARGV,$ARGV[1]); # height defaults to width if not provided
+die "Input image must be in PNG format\n" unless $file =~ /.png$/i;
+die "Sprite width should be 2-16 pixels\n" unless $w >= 2 && $w <= 16;
+die "Sprite height should be at least 1 pixel\n" unless $h > 0;
+
+# Slurp the entire PNG image
+open INPUT, "<$file" and binmode INPUT or die "$file: $!\n";
+read INPUT, $data='', -s $file;
+close INPUT;
+
+# Extract and check the image dimensions
+$data =~ /IHDR(.{8})/s;
+($iw,$ih) = unpack "N2", $1;
+die "Input image (${iw}x${ih}) must be an exact multiple of sprite size (${w}x${h})\n" if ($iw%$w) or ($ih%$h);
+
+# Extract and expand the compressed image data
+($data) = $data =~ /IDAT(.*).{8}IEND/s;
+$data = Compress::Zlib::uncompress($data);
+
+# Remove the type byte from the start of each line, leaving just 0+1 pixel values
+if (length($data) == (($iw+1)*$ih)) { # 8bpp?
+  $data =~ s/.(.{$iw})/$1/sg;
+  @data = map { $_&1 } unpack("C*", $data);
+} elsif (length($data) == (($iw/2+1)*$ih)) { # 4bpp?
+  my $iw_2 = $iw/2;
+  $data =~ s/.(.{$iw_2})/$1/sg;
+  foreach (unpack("C*", $data)) {
+    push @data, ($_>>4)&1, $_&1;
+  }
+} else {
+  die "Image data format is unsupported (size = ".@data." bytes)\n";
+}
+
+# Calculate rows+columns and the expected size of the output data
+($c,$r) = ($iw/$w,$ih/$h);
+$size = int(($w+7)/8)*$h*$r*$c;
+print "Input image ($file) = ${iw}x${ih}, sprite = ${w}x${h}\n" if $opt_v;
+
+foreach $y (0..$r-1)
+{
+  foreach $x (0..$c-1)
+  {
+    foreach $l (0..$h-1) # line
+    {
+      # Calculate the offset of the required bit sequence
+      my $o = ((($y*$h+$l)*$c) + $x) * $w;
+
+      # Convert the individual bits to a binary string then a decimal value
+      my $n = unpack("N", pack("B32", substr("0"x32 . join('', @data[$o..$o+$w-1]), -32)));
+
+      # Pack into 1 or 2 bytes, with the bits left-aligned (MSB)
+      $output .= pack(($w<=8)?"C":"n", $n << (8-($w & 7)));
+    }
+  }
+}
+
+# Sanity check the output data size
+die "Output data ", length($output), " is the wrong size! (should be $size)\n" unless length($output) == $size;
+
+# The output file is the input filename with a .bin extension instead of .png
+$file =~ s/png$/bin/i;
+open OUTPUT, ">$file" and binmode OUTPUT or die "$file: $!\n";
+
+# Determine the size of a single sprite, and strip blank sprites from the end of the data
+$ss = length($output) / ($r*$c);
+$output =~ s/(\0{$ss})*$//;
+print "Output data ($file) = ", length($output), " bytes = ", length($output)/$ss, " sprites\n"  if $opt_v;
+
+print OUTPUT $output;
+close OUTPUT;