diff --git a/intcode.py b/intcode.py
new file mode 100644
index 0000000..d2a9c10
--- /dev/null
+++ b/intcode.py
@@ -0,0 +1,103 @@
+from collections import defaultdict
+from opcodes import run_op, CONTINUE, HALT, WAIT
+
+class StackIO:
+    def __init__(self):
+        self.input_stack  = []
+        self.output_stack = []
+
+    def input(self):
+        return self.input_stack.pop(0)
+
+    def output(self, val):
+        self.output_stack.append(val)
+
+    def wait_for_input(self):
+        return len(self.input_stack) == 0
+
+    def pop_out(self):
+        return self.output_stack.pop(0)
+
+class Memory:
+    def __init__(self, program=[]):
+        self.memory = program[:]
+
+    def write(self, i, val):
+        self.memory += [0] * (i - len(self.memory) + 1)
+        self.memory[i] = val
+
+    def read(self, i):
+        if i >= len(self.memory):
+            return 0
+        return self.memory[i]
+
+    def copy(self):
+        return Memory(self.memory[:])
+
+class Computer(object):
+    def __init__(self, program, IO, i=0, rel_base=0):
+        self.memory = Memory(program)
+        self.IO = IO
+        self.i = i
+        self.rel_base = rel_base
+
+    def run(self):
+        for exe_state in self:
+            if exe_state != CONTINUE:
+                break
+        return exe_state
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        return self.run_opcode()
+
+    def copy(self):
+        return Computer(self.memory.memory[:], self.IO, self.i, self.rel_base)
+
+class IntComp(Computer):
+    run_opcode = run_op
+
+    def copy(self):
+        return IntComp(self.memory.memory[:], self.IO, self.i, self.rel_base)
+
+
+class Display(defaultdict):
+    def __init__(self, encoding):
+        super(Display, self).__init__(int)
+        self.encoding = encoding
+
+    def __str__(self):
+        xs, ys = zip(*self.keys())
+        X, Y = max(xs)+1, max(ys)+1
+        return '\n'.join(''.join(self.encoding[self[(x, y)]]
+                         for x in range(X))
+                            for y in range(Y))
+
+
+
+class DisplayIO(object):
+    def __init__(self, display):
+        self.display = display
+        self.block  = tuple()
+
+    def input(self):
+        return NotImplemented
+
+    def wait_for_input(self):
+        return NotImplemented
+
+    def output(self, x):
+        self.block += (x,)
+        if len(self.block) == 3:
+            self.display[self.block[:2]] = self.block[2]
+            self.block = tuple()
+
+def output(program, input=[], computer=IntComp):
+    IO = StackIO()
+    IO.input_stack = input[:]
+    comp = computer(program, IO)
+    if comp.run() != HALT:
+        return False
+    return IO.output_stack
diff --git a/opcodes.py b/opcodes.py
new file mode 100644
index 0000000..3a8a90b
--- /dev/null
+++ b/opcodes.py
@@ -0,0 +1,98 @@
+from operator import add, mul, eq, lt
+import enum
+
+
+@enum.unique
+class State(enum.Enum):
+    """Execution state class."""
+    CONTINUE = 0
+    HALT     = 1
+    WAIT     = 2
+
+
+class Opcode:
+    def __init__(self, func, parnum):
+        self.parnum = parnum
+        self.run    = func
+
+
+def operation(operator):
+    """Make opcode from operator."""
+    def opcode(state, p1, p2, p3):
+        state.memory.write(p3, operator(state.memory.read(p1), state.memory.read(p2)))
+        state.i += 4
+        return State.CONTINUE
+    return Opcode(opcode, 3)
+
+def jump(flag):
+    def opcode(state, p1, p2):
+        state.i = state.memory.read(p2) if (state.memory.read(p1) > 0)==flag else state.i+3
+        return State.CONTINUE
+    return Opcode(opcode, 2)
+
+def adjust_base(state, p1):
+    state.rel_base += state.memory.read(p1)
+    state.i += 2
+    return State.CONTINUE
+
+def input(state, p1):
+    if state.IO.wait_for_input():
+        return State.WAIT
+    state.memory.write(p1, state.IO.input())
+    state.i += 2
+    return State.CONTINUE
+
+def output(state, p1):
+    state.IO.output(state.memory.read(p1))
+    state.i += 2
+    return State.CONTINUE
+
+
+op_add = operation(add)
+
+op_mul = operation(mul)
+
+op_lt = operation(lt)
+
+op_eq = operation(eq)
+
+op_jump_if_true  = jump(True)
+
+op_jump_if_false = jump(False)
+
+op_adjust_relative_base = Opcode(adjust_base, 1)
+
+op_input = Opcode(input, 1)
+
+op_output = Opcode(output, 1)
+
+op_halt = Opcode(lambda x: State.HALT, 0)
+
+opcodes = {1  : op_add,
+           2  : op_mul,
+           3  : op_input,
+           4  : op_output,
+           5  : op_jump_if_true,
+           6  : op_jump_if_false,
+           7  : op_lt,
+           8  : op_eq,
+           9  : op_adjust_relative_base,
+           99 : op_halt}
+
+def parse_op(op):
+    op = str(op)
+    par_modes, op = op[:-2][::-1], int(op[-2:])
+    par_modes = par_modes + '0'*(opcodes[op].parnum - len(par_modes))
+    return op, map(int, par_modes)
+
+def run_op(state):
+    op, par_modes = parse_op(state.memory.read(state.i))
+    pars = []
+    for pn, mode in enumerate(par_modes, start=1):
+        p = state.i + pn
+        if mode == 0:
+            p = state.memory.read(p)
+        elif mode == 2:
+            p = state.rel_base + state.memory.read(p)
+        pars.append(p)
+    return opcodes[op].run(state, *pars)