diff --git a/data/bootcodex.um b/data/bootcodex.um
new file mode 100644
index 0000000..7a805da
Binary files /dev/null and b/data/bootcodex.um differ
diff --git a/src/bin/um.rs b/src/bin/um.rs
index 7bea400..bc25374 100644
--- a/src/bin/um.rs
+++ b/src/bin/um.rs
@@ -1,5 +1,5 @@
 extern crate um;
-use um::cpu::{Cpu};
+use um::cpu::{Cpu,Console};
 use std::io;
 use std::io::prelude::*;
 use std::fs::File;
@@ -9,8 +9,43 @@ use clap::Parser;
 /// Run a um program
 #[derive(Parser)]
 struct Cli {
+  // debug level
+  #[clap(short, long, default_value_t = 0)]
+  debug: u32,
     /// The path to the program to load
-    program: std::path::PathBuf,
+    program: std::path::PathBuf
+    
+}
+
+struct IoConsole {
+  inptr: usize,
+  inbuf: String
+}
+
+impl IoConsole {
+  pub fn make() -> IoConsole {
+    IoConsole {
+      inptr: 0,
+      inbuf: String::from("")
+    }
+  }
+}
+
+impl Console for IoConsole {
+  fn read(&mut self) -> Option<u8> {
+    if self.inptr >= self.inbuf.len() {
+      if let Err(_) = std::io::stdin().read_line(&mut self.inbuf) {
+        return None;
+      }
+    }
+    let r = self.inbuf.bytes().nth(self.inptr).unwrap();
+    self.inptr +=1;
+    Some(r)
+  }
+  fn write(&mut self, c: u8) {
+    let buf = [c;1];
+    let _ = std::io::stdout().write(&buf);
+  }
 }
 
 
@@ -36,21 +71,11 @@ fn main() -> io::Result<()> {
   }
   
   let mut c = Cpu::new(pgm);
-  cont = true;
-  println!("start\n{}", c.state());
-  while cont {
-    let r = c.step();
-    cont = match r {
-      Ok(_) => {
-        println!("ok\n{}", c.state());
-        true
-      },
-      Err(e) => {
-        println!("Error {:?}", e);
-        false
-      }
-    };
+  c.set_debug(args.debug);
+  let mut cons = IoConsole::make();
+  match c.run(&mut cons) {
+    Err(e) => println!("Error {:?}", e),
+    Ok(_) => ()
   }
   Ok(())
-  
 }
\ No newline at end of file
diff --git a/src/cpu.rs b/src/cpu.rs
index 79502f5..e74678a 100644
--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -27,7 +27,8 @@ pub struct Cpu {
   iarr: u32,
   finger: u32,
   out: Option<u8>,
-  in_reg: Option<u8>
+  in_reg: Option<u8>,
+  debug: u32
 }
 
 
@@ -41,10 +42,14 @@ impl Cpu {
       iarr: 1,
       finger: 0,
       in_reg: None,
-      out: None
+      out: None, 
+      debug: 0
     }
   }
   
+  pub fn set_debug(&mut self, debug: u32) {
+    self.debug = debug;
+  }
   fn gr(&self, r: u8) -> u32{
     self.reg[r as usize]
   }
@@ -215,6 +220,22 @@ impl Cpu {
     Ok(())
   } 
   
+  fn handle_lod(&mut self, i:NormalInstruction) -> Result<(), CpuError>{
+    let aidx = self.gr(i.b);
+    let aoff = self.gr(i.c);
+    if let Some(arr) = self.arr.get(&aidx){
+      if arr.len() > aoff as usize {
+        self.arr.insert(0, arr.clone());
+        self.finger = aoff;
+        Ok(())
+      } else {
+        Err(CpuError::ArrayOutOfBounds)
+      }
+    } else {
+      Err(CpuError::InvalidArray)
+    }
+  } 
+  
   fn exec(&mut self, instruction: Instruction)-> Result<(), CpuError>{
     //println!("{:?}", instruction);
     match instruction {
@@ -231,7 +252,8 @@ impl Cpu {
       Instruction::Abandon(i) => self.handle_abn(i),
       Instruction::Output(i) => self.handle_out(i),
       Instruction::Input(i) => self.handle_inp(i),
-      _ => Err(CpuError::InvalidInstruction)
+      Instruction::Load(i) => self.handle_lod(i),
+      //_ => Err(CpuError::InvalidInstruction)
     }
   }
   
@@ -239,14 +261,19 @@ impl Cpu {
     self.out = None;
     self.in_reg = None;
     let i = self.ins()?;
-    self.exec(i)?;
     self.finger += 1;
+    self.exec(i)?;
     Ok(())
   }
   
   pub fn run(&mut self, console: &mut impl Console) -> Result<(), CpuError> {
   let mut cont = true;
+   
    while cont {
+     if self.debug > 5 {
+        println!("{:?}", self.ins());
+        println!("{}", self.state());
+      }
     cont = match self.step() {
       Ok(_) => true,
       Err(CpuError::ProgramEnd) => false,
@@ -632,4 +659,46 @@ mod tests{
     assert_eq!(c.reg, exp);
     Ok(())
   }
+  
+  #[test]
+  fn test_lod() -> Result<(), CpuError> {
+    let pgm = vec!( ezop(12, 1, 2, 3) );
+    let mut c = Cpu::new(pgm);
+    c.arr.insert(1338, vec![0,0,0,1339]);
+    c.reg = [0, 0, 1338, 3, 0, 0, 0, 0];
+    c.step()?;
+    assert_eq!(c.finger, 3);
+    if let Some(arr) = c.arr.get(&0){
+      assert_eq!(arr,&vec![0,0,0,1339] );
+      Ok(())
+    } else {
+      Err(CpuError::InvalidArray)
+    }
+  }
+  
+  #[test]
+  fn test_lod_inv() -> Result<(), String> {
+    let pgm = vec!( ezop(12, 1, 2, 3) );
+    let mut c = Cpu::new(pgm);
+    c.reg = [0, 0, 1338, 3, 0, 0, 0, 0];
+
+    match c.step() {
+      Err(CpuError::InvalidArray) => Ok(()),
+      Ok(_) => Err(format!("unexpected ok")),
+      Err(e) => Err(format!("unexpected err {:?}", e))
+    }
+  }
+  
+    #[test]
+  fn test_lod_off() -> Result<(), String> {
+    let pgm = vec!( ezop(12, 1, 2, 3) );
+    let mut c = Cpu::new(pgm);
+    c.reg = [0, 0, 1338, 3, 0, 0, 0, 0];
+    c.arr.insert(1338, vec![0]);
+    match c.step() {
+      Err(CpuError::ArrayOutOfBounds) => Ok(()),
+      Ok(_) => Err(format!("unexpected ok")),
+      Err(e) => Err(format!("unexpected err {:?}", e))
+    }
+  }
 }
\ No newline at end of file