Added Bank switching code

lib/n65/directives/ines_header.rb

@@ -3,12 +3,12 @@ require_relative '../instruction_base'
 
 module N65
 
-
   ####
-  ##  This directive instruction can setup an ines header
+  ##  This directive instruction can setup an iNES header
   class INESHeader < InstructionBase
-    attr_reader :prog, :char, :mapper, :mirror
+    attr_reader :prog, :char, :mapper, :mirror, :battery_backed, :fourscreen_vram, :prog_ram, :tv
 
+    Defaults = {prog: 1, char: 0, mapper: 0, mirror: 0, battery_backed: 0, fourscreen_vram: 0, prog_ram: 0, tv: 0}
 
     ####
     ##  Implementation of the parser for this directive
@@ -17,14 +17,36 @@ module N65
       return nil if match_data.nil?
 
       header = JSON.parse(match_data[1])
-      INESHeader.new(header['prog'], header['char'], header['mapper'], header['mirror'])
+      header = header.inject({}) do |hash, (key, val)|
+        hash[key.to_sym] = val
+        hash
+      end
+
+      header = Defaults.merge(header)
+
+      INESHeader.new(
+        header[:prog],
+        header[:char],
+        header[:mapper],
+        header[:mirror],
+        header[:battery_backed],
+        header[:fourscreen_vram],
+        header[:prog_ram],
+        header[:tv])
     end
 
 
     ####
     ##  Construct a header
-    def initialize(prog, char, mapper, mirror)
-      @prog, @char, @mapper, @mirror = prog, char, mapper, mirror
+    def initialize(prog, char, mapper, mirror, battery_backed, fourscreen_vram, prog_ram, tv)
+      @prog = prog
+      @char = char
+      @mapper = mapper
+      @mirror = mirror
+      @battery_backed = battery_backed
+      @fourscreen_vram = fourscreen_vram
+      @prog_ram = prog_ram
+      @tv = tv
     end
 
 
@@ -36,16 +58,38 @@ module N65
 
 
     ####
-    ##  Emit the header bytes, this is not exactly right, but it works for now.
+    ##  Emit the header bytes
     def emit_bytes
-      [0x4E, 0x45, 0x53, 0x1a, @prog, @char, @mapper, @mirror, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0]
+
+      mapper_lo_nybble = (@mapper & 0x0f)
+      mapper_hi_nybble = (@mapper & 0xf0) >> 4
+
+      flag6 = 0
+      flag6 |= 0x1 if @mirror == 1
+      flag6 |= 0x2 if @battery_backed == 1
+      flag6 |= 0x8 if @fourscreen_vram == 1
+      flag6 |= (mapper_lo_nybble << 4)
+
+      flag7 = 0
+      flag7 |= (mapper_hi_nybble << 4)
+
+      [0x4E, 0x45, 0x53, 0x1a,
+       @prog & 0xff,
+       @char & 0xff,
+       flag6 & 0xff,
+       flag7 & 0xff,
+       @prog_ram & 0xff,
+       0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0]
     end
 
 
     ####
     ##  Display
     def to_s
-      ".ines {\"prog\": #{@prog}, \"char\": #{@char}, \"mapper\": #{@mapper}, \"mirror\": #{@mirror}}"
+      [".ines {\"prog\": #{@prog}, \"char\": #{@char}, \"mapper\": #{@mapper}, ",
+       "\"mirror\": #{@mirror}}, \"battery_backed\": #{@battery_backed}, ",
+       "\"fourscreen_vram\": #{@fourscreen_vram}, \"prog_ram\": #{@prog_ram}, ",
+       "\"tv\": #{@tv}"].join
     end
 
   end

lib/n65/version.rb

@@ -1,3 +1,3 @@
 module N65
-  VERSION ||= "1.0.0"
+  VERSION ||= "1.1.0"
 end