1 files changed, 56 insertions, 0 deletions
diff --git a/atk16_emu/memory.py b/atk16_emu/memory.py
new file mode 100644
index 0000000..2ce9c85
--- /dev/null
+++ b/atk16_emu/memory.py
@@ -0,0 +1,56 @@
+import random
+
+class Register:
+  def __init__(self, bits: int):
+    self.bits = bits
+    self.value = random.randrange(0, 2 ** bits)
+
+  def set_value(self, value: int):
+    if value < 0 or value >= 2 ** self.bits:
+      raise ValueError(f"Value {value} is out of range for {self.bits}-bit register")
+
+    self.value = value
+
+class Counter:
+  def __init__(self, bits: int):
+    self.bits = bits
+    self.value = random.randrange(0, 2 ** bits)
+
+  def step(self):
+    self.value = (self.value + 1) % (2 ** self.bits)
+
+  def reset(self):
+    self.value = 0
+
+class ROM:
+  def __init__(self, addr_bits: int, data_bits: int):
+    self.addr_bits = addr_bits
+    self.data_bits = data_bits
+    self.memory = [random.randrange(0, 2 ** data_bits) for _ in range(2 ** addr_bits)]
+
+  def read(self, addr: int) -> int:
+    if addr < 0 or addr >= 2 ** self.addr_bits:
+      raise ValueError(f"Address {addr} is out of range for {self.addr_bits}-bit ROM")
+
+    return self.memory[addr]
+
+class RAM:
+  def __init__(self, addr_bits: int, data_bits: int):
+    self.addr_bits = addr_bits
+    self.data_bits = data_bits
+    self.memory = [random.randrange(0, 2 ** data_bits) for _ in range(2 ** addr_bits)]
+
+  def read(self, addr: int) -> int:
+    if addr < 0 or addr >= 2 ** self.addr_bits:
+      raise ValueError(f"Address {addr} is out of range for {self.addr_bits}-bit RAM")
+
+    return self.memory[addr]
+
+  def write(self, addr: int, value: int):
+    if addr < 0 or addr >= 2 ** self.addr_bits:
+      raise ValueError(f"Address {addr} is out of range for {self.addr_bits}-bit RAM")
+
+    if value < 0 or value >= 2 ** self.data_bits:
+      raise ValueError(f"Value {value} is out of range for {self.data_bits}-bit RAM")
+
+    self.memory[addr] = value
+\ No newline at end of file