diff --git a/build/unixv0.simh b/build/unixv0.simh
index ddd4927..4591561 100644
--- a/build/unixv0.simh
+++ b/build/unixv0.simh
@@ -3,6 +3,7 @@ set cpu eae
 set cpu history=100
 show cpu
 
+set tti 8b
 set rb ena
 att rb image.fs
 show dev