createbin: avoid reserved bits

skip in loop, to avoid duplicates

1 files changed, 4 insertions, 0 deletions

diff --git a/nandgame/assembler/createbin.py b/nandgame/assembler/createbin.py
index d4a2e7a..3713389 100755
--- a/nandgame/assembler/createbin.py
+++ b/nandgame/assembler/createbin.py
@@ -11,4 +11,8 @@ with open("allins.bin", "wb") as f:
     f.write(ins.to_bytes(2))
 
     for ins in range(0x8000, 0xffff + 1):
+        # unused bytes, force 1
+        if (ins & 0x6800) != 0x6800:
+            continue
+
         f.write(ins.to_bytes(2))