From 6d29ec00fb045b39e3564c4bfa9191182dea4aa4 Mon Sep 17 00:00:00 2001
From: Jared Miller <jared@smell.flowers>
Date: Tue, 10 Feb 2026 16:59:29 -0500
Subject: [PATCH] Implement stub opcodes for game compatibility

set_colour, piracy, erase_line, get_cursor, not_v5, print_table
---
 src/mudlib/zmachine/zcpu.py | 43 +++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 16 deletions(-)

diff --git a/src/mudlib/zmachine/zcpu.py b/src/mudlib/zmachine/zcpu.py
index 5c59c1a..0053577 100644
--- a/src/mudlib/zmachine/zcpu.py
+++ b/src/mudlib/zmachine/zcpu.py
@@ -463,8 +463,8 @@ class ZCpu:
         self._call(routine_addr, [arg1], False)
 
     def op_set_colour(self, *args):
-        """TODO: Write docstring here."""
-        raise ZCpuNotImplemented
+        """Set foreground and background colors (no-op for text MUD)."""
+        pass
 
     def op_throw(self, *args):
         """TODO: Write docstring here."""
@@ -716,8 +716,8 @@ class ZCpu:
         self._branch(expected_checksum == actual_checksum)
 
     def op_piracy(self, *args):
-        """TODO: Write docstring here."""
-        raise ZCpuNotImplemented
+        """Anti-piracy check. Always branches true (all interpreters pass this)."""
+        self._branch(True)
 
     ## VAR opcodes (opcodes 224-255)
 
@@ -913,16 +913,17 @@ class ZCpu:
             self._ui.screen.erase_window(window_number)
 
     def op_erase_line(self, *args):
-        """TODO: Write docstring here."""
-        raise ZCpuNotImplemented
+        """Erase current line on screen (no-op for text MUD)."""
+        pass
 
     def op_set_cursor(self, x, y):
         """Set the cursor position within the active window."""
         self._ui.screen.set_cursor_position(x, y)
 
-    def op_get_cursor(self, *args):
-        """TODO: Write docstring here."""
-        raise ZCpuNotImplemented
+    def op_get_cursor(self, table_addr):
+        """Get cursor position into table. For MUD, always write row=1, col=1."""
+        self._memory.write_word(table_addr, 1)  # row
+        self._memory.write_word(table_addr + 2, 1)  # col
 
     def op_set_text_style(self, text_style):
         """Set the text style."""
@@ -1004,9 +1005,10 @@ class ZCpu:
         self._write_result(0)
         self._branch(False)
 
-    def op_not_v5(self, *args):
-        """TODO: Write docstring here."""
-        raise ZCpuNotImplemented
+    def op_not_v5(self, value):
+        """Bitwise NOT (VAR form). Same as op_not."""
+        result = ~value & 0xFFFF
+        self._write_result(result)
 
     def op_call_vn(self, routine_addr, *args):
         """Call routine with up to 3 arguments and discard the result."""
@@ -1055,7 +1057,12 @@ class ZCpu:
             offset = pos + word_len
 
     def op_encode_text(self, *args):
-        """TODO: Write docstring here."""
+        """Encode ZSCII text to Z-encoded string (V5+).
+
+        This opcode converts ZSCII text into Z-machine's packed text format
+        (3 characters per 2 bytes). Complex operation, rarely used.
+        Not implemented - will raise ZCpuNotImplemented if any game calls it.
+        """
         raise ZCpuNotImplemented
 
     def op_copy_table(self, first, second, size):
@@ -1080,9 +1087,13 @@ class ZCpu:
                 for i in range(count - 1, -1, -1):
                     self._memory[second + i] = self._memory[first + i]
 
-    def op_print_table(self, *args):
-        """TODO: Write docstring here."""
-        raise ZCpuNotImplemented
+    def op_print_table(self, zscii_text, width, height=1, skip=0):
+        """Formatted table printing (no-op for text MUD).
+
+        Spec: print width chars per line for height lines from zscii_text.
+        Skip bytes between rows. For now, no-op to avoid crashes.
+        """
+        pass
 
     def op_check_arg_count(self, arg_number):
         """Branch if the Nth argument was passed to the current routine."""