diff --git a/2019/day7/day7.hs b/2019/day7/day7.hs
index 047487e..a94bf5a 100644
--- a/2019/day7/day7.hs
+++ b/2019/day7/day7.hs
@@ -2,8 +2,10 @@ import Data.List.Split
 import qualified Data.List as L
 import Data.Vector as V
 import Data.Char
+import Control.DeepSeq as DeepSeq
 
 data OutAction = Continue | Output | Halt deriving (Enum, Eq, Show)
+data Mode = Position | Immediate | Relative deriving (Enum, Eq, Show)
 type Tape = Vector Int
 type TapeSection = Vector Int
 type TuringMachine = (Tape,Int)
@@ -52,22 +54,20 @@ getOpModes opvec = (op_dedup,parsed_modes)
           op_dedup = if L.last op == '0' then [L.head op] else op
 
 step :: TapeSection -> (TuringMachine, [Int], [Int]) -> (TuringMachine, OutAction, [Int], [Int])
-step opvec ((t,p),input,val) = case op of
-    "1" -> (tm_binop (+),Continue,input,val)
-    "2" -> (tm_binop (*),Continue,input,val)
-    "3" -> (new_tm t (L.head input),Continue,L.tail input,val)
-    "4" -> ((t,p),Output,input,V.last params:val)
-    "5" -> ((t, if params ! 0/=0 then params ! 1 else p),Continue,input,val)
-    "6" -> ((t, if params ! 0==0 then params ! 1 else p),Continue,input,val)
-    "7" -> (new_tm t (if (params ! 0)<(params ! 1)
-                    then 1 else 0),Continue,input,val)
-    "8" -> (new_tm t (if (params ! 0)==(params ! 1)
-                    then 1 else 0),Continue,input,val)
-    "99" -> ((t,p),Halt,input,val)
+step opvec ((t,p),input,output) = case op of
+    "1" -> (tm_binop (+),Continue,input,output)
+    "2" -> (tm_binop (*),Continue,input,output)
+    "3" -> (new_tm t $ L.head input,Continue,L.tail input,output)
+    "4" -> ((t,p),Output,input,V.last params:output)
+    "5" -> ((t, if params ! 0/=0 then params ! 1 else p),Continue,input,output)
+    "6" -> ((t, if params ! 0==0 then params ! 1 else p),Continue,input,output)
+    "7" -> (tm_binop (\x y->if x<y then 1 else 0),Continue,input,output)
+    "8" -> (tm_binop (\x y->if x==y then 1 else 0),Continue,input,output)
+    "99" -> ((t,p),Halt,input,output)
     where (op,m) = getOpModes opvec
           params = paramChange m opvec t
           tm_binop x = new_tm t ((params ! 0) `x` (params ! 1))
-          new_tm t x = (t // [(V.last opvec, x)],p)
+          new_tm t x = DeepSeq.force (t // [(V.last opvec, x)],p)
 
 execSteps :: (TuringMachine, [Int], [Int], OutAction) -> (TuringMachine, [Int], [Int], OutAction)
 execSteps ((t,p),input,output,halt) =