diff --git a/simulator.rkt b/simulator.rkt
index fbff60f..2425d85 100644
--- a/simulator.rkt
+++ b/simulator.rkt
@@ -166,9 +166,42 @@
                     (error 'step-perform "Procedure register doesn't hold a procedure: ~s"
                            a-proc)]))])))
 
+(: get-target-updater (Target -> (machine SlotValue -> machine)))
+(define (get-target-updater t)
+  (cond
+    [(eq? t 'proc)
+     proc-update]
+    [(eq? t 'val)
+     val-update]
+    [(EnvLexicalReference? t)
+     (lambda: ([m : machine] [v : SlotValue])
+              (env-mutate m (EnvLexicalReference-depth t) v))]))
+
+
 (: step-assign-primitive-operation (machine AssignPrimOpStatement -> machine))
 (define (step-assign-primitive-operation m stmt)
-  m)
+  (let: ([op : PrimitiveOperator (AssignPrimOpStatement-op stmt)]
+         [target-updater : (machine SlotValue -> machine)
+                         (get-target-updater (AssignPrimOpStatement-target stmt))])
+        (cond
+          [(GetCompiledProcedureEntry? op)
+           (let: ([a-proc : SlotValue (machine-proc m)])
+                 (cond
+                   [(closure? a-proc)
+                    (target-updater m (closure-label a-proc))]
+                   [else
+                    (error 'get-copmiled-procedure-entry)]))]
+
+          [(MakeCompiledProcedure? op)
+           m]
+          [(ApplyPrimitiveProcedure? op)
+           m]
+          [(LookupLexicalAddress? op)
+           m]
+          [(LookupToplevelAddress? op)
+           m]
+          [(GetControlStackLabel? op)
+           m])))
            
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
diff --git a/test-simulator.rkt b/test-simulator.rkt
index 84a5e29..f7f0ec0 100644
--- a/test-simulator.rkt
+++ b/test-simulator.rkt
@@ -288,3 +288,25 @@
 
 
 
+(let ([m 
+       (make-machine (make-undefined) 
+                     (make-closure 'procedure-entry (list 1 2 3))
+                     (list true false) ;; existing environment holds true, false
+                     '() 
+                     0 
+                     (list->vector `(,(make-AssignPrimOpStatement 'val (make-GetCompiledProcedureEntry)))))])
+  (test (machine-val (run m))
+        'procedure-entry))
+
+
+
+#;(let ([m (new-machine `(,(make-AssignPrimOpStatement (make-MakeCompiledProcedure))))])
+  (test ...))
+#;(let ([m (new-machine `(,(make-AssignPrimOpStatement (make-ApplyPrimitiveProcedure))))])
+  (test ...))
+#;(let ([m (new-machine `(,(make-AssignPrimOpStatement (make-LookupLexicalAddress))))])
+  (test ...))
+#;(let ([m (new-machine `(,(make-AssignPrimOpStatement (make-LookupToplevelAddress))))])
+  (test ...))
+#;(let ([m (new-machine `(,(make-AssignPrimOpStatement (make-GetControlStackLabel))))])
+  (test ...))
\ No newline at end of file