diff --git a/src/vm.rs b/src/vm.rs
index bad2fe2..29eb95d 100644
--- a/src/vm.rs
+++ b/src/vm.rs
@@ -4,7 +4,7 @@ pub type VM_Word = i64;
 #[repr(u64)]
 pub enum VM_Instruction {
     Nop, Jmp, Call, Branch, Ret,
-    Lit, Dup, Drop, Swap, Rot,
+    Lit, Pick, Roll, Dup, Drop, Swap, Rot,
     Fetch, Store,
     Accept, Emit,
     Add, //Sub, Mul, Div, Rem,
@@ -103,6 +103,23 @@ impl VM {
                 let val = char::from(self.data_stack.pop().expect("emit expects value") as u8);
                 print!("{}", val);
             }
+            VM_Instruction::Pick => {
+                let n = self.data_stack.pop().expect("pick requires index") as usize;
+                self.data_stack.push( *self.data_stack.get( self.data_stack.len() - n ).expect("pick invalid index") );
+            }
+            VM_Instruction::Roll => {
+                let n = self.data_stack.pop().expect("pick requires index") as usize;
+                let l = self.data_stack.len();
+                if n <= l {
+                    if n > 1 {
+                        let val = self.data_stack.remove( l-n );
+                        self.data_stack.push( val );
+                    }
+                } else {
+                    eprintln!("stack = {:?}", self.data_stack);
+                    eprintln!("roll invalid index");
+                }
+            }
             VM_Instruction::Dup => {
                 self.data_stack.push( *self.data_stack.last().expect("dup expect val") );
             }
@@ -114,7 +131,7 @@ impl VM {
                 let b = self.data_stack.pop().expect("swap expects value");
                 self.data_stack.push(a);
                 self.data_stack.push(b);
-            }            
+            }
             VM_Instruction::Rot => {
                 let a = self.data_stack.pop().expect("rot expects value");
                 let b = self.data_stack.pop().expect("rot expects value");