diff --git a/2019/day21-p1.springscript b/2019/day21-p1.springscript
new file mode 100644
index 0000000..94a869b
--- /dev/null
+++ b/2019/day21-p1.springscript
@@ -0,0 +1,6 @@
+OR D J
+NOT C T
+AND T J
+NOT A T
+OR T J
+WALK
diff --git a/2019/day21.py b/2019/day21.py
new file mode 100644
index 0000000..7ff6692
--- /dev/null
+++ b/2019/day21.py
@@ -0,0 +1,20 @@
+import sys
+
+from intcode import AIC
+
+
+def main():
+    codes = AIC.parse_file("day21.txt")
+    ss = SSIC(codes, script=sys.stdin.read())
+    ss.run()
+
+
+class SSIC(AIC):
+
+    def __init__(self, *args, script="", **kwargs):
+        super().__init__(*args, **kwargs)
+        self.input_text = script
+
+
+if __name__ == "__main__":
+    main()
diff --git a/2019/intcode.py b/2019/intcode.py
index 445d3ba..83597ec 100644
--- a/2019/intcode.py
+++ b/2019/intcode.py
@@ -162,3 +162,25 @@ class Intcode(object):
 
     def output_data(self, data):
         print(">", data)
+
+
+class AIC(Intcode):
+    """ASCII-enabled Intcode interpreter."""
+    LN = ord("\n")
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.input_text = ""
+
+    def input_data(self):
+        data, self.input_text = self.input_text[0], self.input_text[1:]
+        return ord(data)
+
+    def output_data(self, data):
+        if data > 256:
+            self.handle_int_output(data)
+        else:
+            print(chr(data), end="")
+
+    def handle_int_output(self, i):
+        print(f"Int output: {i}.")