4 files changed, 90 insertions, 7 deletions
diff --git a/atk16_emu/cli.py b/atk16_emu/cli.py
index fcea56b..9cb268a 100644
--- a/atk16_emu/cli.py
+++ b/atk16_emu/cli.py
@@ -7,24 +7,29 @@ from .debugger import Debugger
 class Options:
   rom_image_path: str | None
   debugger_enabled: bool
+  peripherals_enabled: bool
 
 options = Options(
   rom_image_path=None,
   debugger_enabled=False,
+  peripherals_enabled=True,
 )
 
 def print_help():
-  print("Usage: emu_cli.py [-d] [-h|--help] <rom_path>")
+  print("Usage: emu_cli.py [-d] [-n] [-h|--help] <rom_path>")
   print("")
   print("Options:")
   print("  <rom_path>: path to the rom image")
   print("  -h: print help")
   print("  -d: enable debugger")
+  print("  -n: no peripherals (useful for automated testing)")
 
 def main():
   for arg in sys.argv[1:]:
     if arg == "-d":
       options.debugger_enabled = True
+    elif arg == "-n":
+      options.peripherals_enabled = False
     elif arg == "-h" or arg == "--help" or arg == "-?":
       print_help()
       sys.exit(0)
@@ -43,7 +48,7 @@ def main():
     with open(options.rom_image_path, "rb") as f:
       rom_image = bytearray(f.read())
 
-    machine = Machine()
+    machine = Machine(options.peripherals_enabled)
     machine.load_rom_image(rom_image)
     machine.reset()
     machine.run_until_halted()
@@ -54,7 +59,7 @@ def main():
     machine.print_state_summary()
 
   else:
-    debugger = Debugger()
+    debugger = Debugger(options.peripherals_enabled)
     debugger.load_rom_image(options.rom_image_path)
     debugger.activate()
 
diff --git a/atk16_emu/debugger.py b/atk16_emu/debugger.py
index 02ea5f5..a157e68 100644
--- a/atk16_emu/debugger.py
+++ b/atk16_emu/debugger.py
@@ -29,10 +29,10 @@ def without_colors(s: str):
 class Debugger:
   HISTORY_MAX_LEN = 1000
 
-  def __init__(self):
+  def __init__(self, peripherals_enabled: bool):
     self.rom_image = None
     self.breakpoints: set[int] = set()
-    self.machine = Machine()
+    self.machine = Machine(peripherals_enabled)
     self.machine.reset()
     self.machine.run()
     self.dbg_addr_info: dict[int, DbgAddrInfo] = {}
diff --git a/atk16_emu/emu.py b/atk16_emu/emu.py
index 8277d00..a118472 100644
--- a/atk16_emu/emu.py
+++ b/atk16_emu/emu.py
@@ -5,6 +5,7 @@ import sys
 import time
 from .opcodes import *
 from .colors import C
+from .peripherals import Graphics, DummyGraphics
 
 class Register:
   def __init__(self, bits: int):
@@ -156,7 +157,7 @@ class ALU:
     raise ValueError(f"Invalid ALU S: {S}")
 
 class Machine:
-  def __init__(self):
+  def __init__(self, peripherals_enabled: bool = False):
     self.rom = ROM(15, 16)
     self.ram = RAM(15, 16)
     self.alu = ALU()
@@ -181,9 +182,18 @@ class Machine:
     self.steps_taken = 0
     self.running = False
 
+    self.peripherals_enabled = peripherals_enabled
+    if peripherals_enabled:
+      self.graphics = Graphics()
+    else:
+      self.graphics = DummyGraphics()
+
   def make_copy(self):
     new_machine = Machine()
 
+    new_machine.peripherals_enabled = self.peripherals_enabled
+    new_machine.graphics = self.graphics
+
     new_machine.rom = ROM(self.rom.addr_bits, self.rom.data_bits)
     new_machine.rom.memory = self.rom.memory.copy()
 
@@ -242,7 +252,14 @@ class Machine:
       raise ValueError(f"Cannot write to ROM, addr: 0x{addr:>04x}")
     else:
       # TODO: Implement memory-mapped I/O
-      self.ram.write(addr & 0x7FFF, value)
+      if addr == 0xE002 and value == 0b00:
+        self.graphics.deactivate()
+      elif addr == 0xE002 and value == 0b01:
+        self.graphics.activate_tpu()
+      elif addr == 0xE002 and value == 0b10:
+        self.graphics.activate_ppu()
+      else:
+        self.ram.write(addr & 0x7FFF, value)
 
   def get_nth_register(self, n: int) -> Register:
     if n < 0 or n >= 8:
@@ -393,6 +410,8 @@ class Machine:
       print(f"Error while executing instruction 0b{instr:>016b} (0x{instr:>04x}) at address 0x{pc_addr:>04x}", file=sys.stderr)
       raise
 
+    self.graphics.step()
+
   def decode(self, instr: int):
     opcode = (instr & 0xF000) >> 12
     opdata = instr & 0x0FFF
diff --git a/atk16_emu/peripherals.py b/atk16_emu/peripherals.py
new file mode 100644
index 0000000..dc35e3e
--- /dev/null
+++ b/atk16_emu/peripherals.py
@@ -0,0 +1,59 @@
+import pygame
+
+class TPU:
+  def __init__(self):
+    self.surface: pygame.Surface | None = None
+    self.text_mem = []
+
+  def frame(self):
+    # TODO
+    pass
+
+class Graphics:
+  def __init__(self):
+    pygame.init()
+    pygame.display.init()
+
+    self.surface = None
+    self.clock = pygame.time.Clock()
+    self.tpu = TPU()
+    self.active_picture_unit: TPU | None = None
+
+  def activate_tpu(self):
+    if self.active_picture_unit:
+      pygame.display.quit()
+
+    pygame.display.init()
+    self.surface = pygame.display.set_mode((320, 240))
+    self.active_picture_unit = self.tpu
+    self.active_picture_unit.surface = self.surface
+
+  def activate_ppu(self):
+    raise NotImplementedError()
+
+  def deactivate(self):
+    self.active_picture_unit = None
+    pygame.display.quit()
+
+  def step(self):
+    if self.active_picture_unit:
+      self.active_picture_unit.frame()
+
+      pygame.display.flip()
+      self.clock.tick(60)
+
+class DummyGraphics:
+  def __init__(self):
+    pass
+
+  def activate_tpu(self):
+    pass
+
+  def activate_ppu(self):
+    pass
+
+  def deactivate(self):
+    pass
+
+  def step(self):
+    pass