diff --git a/.gitignore b/.gitignore
index 32fc6a5..a0b9c11 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 /target
-
+*.log
+*.reidc
 
 #Added by cargo
 #
diff --git a/reid_src/test.reid b/reid_src/test.reid
index 971ff3f..cdbddb0 100644
--- a/reid_src/test.reid
+++ b/reid_src/test.reid
@@ -1 +1,2 @@
-let gotus = 3;
\ No newline at end of file
+let gotus = "Hello, world!";
+print(gotus);
\ No newline at end of file
diff --git a/src/args.rs b/src/args.rs
index 65bebf4..66bfc99 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -5,8 +5,10 @@ use argh::FromArgs;
 #[derive(FromArgs, PartialEq, Debug)]
 #[argh(description = "reid compiler and Virtual Machine")]
 pub struct MainOpt {
+    #[argh(positional, description = "run compiled .reidc from <path>")]
+    pub run_path: Option<PathBuf>,
     #[argh(subcommand)]
-    pub subcommand: Subcommand,
+    pub subcommand: Option<Subcommand>,
 }
 
 #[derive(FromArgs, PartialEq, Debug)]
@@ -14,7 +16,6 @@ pub struct MainOpt {
 pub enum Subcommand {
     Compile(Compile),
     Run(Run),
-    CompileAndRun(CompileAndRun),
 }
 
 #[derive(FromArgs, PartialEq, Debug)]
@@ -27,27 +28,16 @@ pub struct Compile {
     #[argh(positional, description = "source .reid path")]
     pub source: String,
     #[argh(positional, description = "output .reidc path")]
-    pub output: String,
+    pub output: Option<String>,
 }
 
 #[derive(FromArgs, PartialEq, Debug)]
 #[argh(
     subcommand,
     name = "run",
-    description = "run compiled .reidc from <path>"
-)]
-pub struct Run {
-    #[argh(positional, description = "otus 2")]
-    pub path: String,
-}
-
-#[derive(FromArgs, PartialEq, Debug)]
-#[argh(
-    subcommand,
-    name = "c_run",
     description = "compile and run given .reid file"
 )]
-pub struct CompileAndRun {
+pub struct Run {
     #[argh(positional, description = "source .reid path")]
     pub source: PathBuf,
 }
diff --git a/src/compiler.rs b/src/compiler.rs
index 2ec1758..361bf50 100644
--- a/src/compiler.rs
+++ b/src/compiler.rs
@@ -7,9 +7,9 @@ use super::parser::{Expression, LiteralPattern, ParsedReid, Pattern, Position, S
 use super::vm::{FunctionSignature, VariableType};
 
 type Variable = (HeapID, VariableType);
-pub type FuncID = usize;
-pub type HeapID = usize;
-pub type RegID = usize;
+pub type FuncID = u16;
+pub type HeapID = u16;
+pub type RegID = u8;
 
 #[derive(Debug, Clone)]
 pub enum Command {
@@ -192,11 +192,11 @@ impl Scope {
         }
     }
 
-    fn find_function(&self, signature: &FunctionSignature) -> Option<(usize, &FunctionSignature)> {
+    fn find_function(&self, signature: &FunctionSignature) -> Option<(FuncID, &FunctionSignature)> {
         let mut found = None;
         for (idx, func) in self.functions.iter().enumerate() {
             if func == signature {
-                found = Some((idx, func));
+                found = Some((idx as u16, func));
             }
         }
         found
diff --git a/src/errors.rs b/src/errors.rs
index 79762e4..28a543c 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -9,6 +9,9 @@ use super::vm::VariableType;
 #[derive(Debug)]
 pub enum GenericError {
     StdIOError(io::Error),
+    CorruptedBytecode,
+    SyntaxError(SyntaxError),
+    CompilerError(CompilerError),
 }
 
 impl From<io::Error> for GenericError {
@@ -17,6 +20,32 @@ impl From<io::Error> for GenericError {
     }
 }
 
+impl From<SyntaxError> for GenericError {
+    fn from(error: SyntaxError) -> Self {
+        Self::SyntaxError(error)
+    }
+}
+
+impl From<CompilerError> for GenericError {
+    fn from(error: CompilerError) -> Self {
+        Self::CompilerError(error)
+    }
+}
+
+impl Display for GenericError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let text = match self {
+            GenericError::StdIOError(err) => format!("IO Error: {}", err),
+            GenericError::CorruptedBytecode => {
+                "Failed to read bytecode. Bytecode might be corrupted.".to_string()
+            }
+            GenericError::SyntaxError(err) => format!("Syntax Error: {}", err),
+            GenericError::CompilerError(err) => format!("Compiler Error: {}", err),
+        };
+        write!(f, "{}", text)
+    }
+}
+
 #[derive(Debug)]
 pub enum SyntaxError {
     #[allow(dead_code)]
diff --git a/src/file_io.rs b/src/file_io.rs
index e1b98d9..cabbd40 100644
--- a/src/file_io.rs
+++ b/src/file_io.rs
@@ -3,12 +3,165 @@ use std::io::prelude::*;
 use std::io::BufReader;
 use std::path::Path;
 
+use super::compiler::{Command, CompiledReid};
 use super::errors::GenericError;
+use super::vm::VariableType;
 
-pub fn open_file(path: &Path) -> Result<String, GenericError> {
+pub fn open_source(path: &Path) -> Result<String, GenericError> {
     let file = File::open(path)?;
     let mut reader = BufReader::new(file);
     let mut text = String::new();
     reader.read_to_string(&mut text)?;
     Ok(text)
 }
+
+pub fn into_bytecode(compiled: &CompiledReid) -> Vec<u8> {
+    let mut list = Vec::new();
+    let iter = compiled.list.iter();
+    for item in iter {
+        list.append(&mut item.into_u8());
+    }
+    list
+}
+
+pub fn write_bytecode(bytecode: Vec<u8>, path: &Path) -> Result<(), GenericError> {
+    let mut file = File::create(path)?;
+    file.write_all(&bytecode)?;
+    Ok(())
+}
+
+pub fn open_bytecode(path: &Path) -> Result<CompiledReid, GenericError> {
+    let file = File::open(path)?;
+    let mut reader = BufReader::new(file);
+    let mut commands = Vec::new();
+    let mut iter = reader.fill_buf()?.iter().peekable();
+    while iter.peek().is_some() {
+        if let Some(command) = Command::from_u8(&mut iter) {
+            commands.push(command);
+        } else {
+            return Err(GenericError::CorruptedBytecode);
+        }
+    }
+    Ok(CompiledReid { list: commands })
+}
+
+impl VariableType {
+    fn into_u8(&self) -> u8 {
+        match self {
+            VariableType::TypeString => 0,
+            VariableType::TypeI32 => 1,
+        }
+    }
+
+    fn from_u8(num: u8) -> Option<VariableType> {
+        match num {
+            0 => Some(VariableType::TypeString),
+            1 => Some(VariableType::TypeI32),
+            _ => None,
+        }
+    }
+}
+
+impl Command {
+    fn id(&self) -> u8 {
+        match *self {
+            Command::InitializeVariable(..) => 0,
+            Command::BeginScope => 1,
+            Command::EndScope => 2,
+            Command::Pop(..) => 3,
+            Command::Push(..) => 4,
+            Command::AssignVariable(..) => 5,
+            Command::VarToReg(..) => 6,
+            Command::StringLit(..) => 7,
+            Command::I32Lit(..) => 8,
+            Command::FunctionCall(..) => 9,
+        }
+    }
+
+    fn from_u8<'a, T: Iterator<Item = &'a u8>>(iter: &mut T) -> Option<Command> {
+        let id = iter.next()?;
+        match id {
+            0 => {
+                let heapid = u16::from_be_bytes([*iter.next()?, *iter.next()?]);
+                Some(Command::InitializeVariable(
+                    heapid,
+                    VariableType::from_u8(*iter.next()?)?,
+                ))
+            }
+            1 => Some(Command::BeginScope),
+            2 => Some(Command::EndScope),
+            3 => Some(Command::Pop(*iter.next()?)),
+            4 => Some(Command::Push(*iter.next()?)),
+            5 => {
+                let heapid = u16::from_be_bytes([*iter.next()?, *iter.next()?]);
+                Some(Command::AssignVariable(heapid, *iter.next()?))
+            }
+            6 => {
+                let heapid = u16::from_be_bytes([*iter.next()?, *iter.next()?]);
+                Some(Command::VarToReg(heapid, *iter.next()?))
+            }
+            7 => {
+                let len = u32::from_be_bytes([
+                    *iter.next()?,
+                    *iter.next()?,
+                    *iter.next()?,
+                    *iter.next()?,
+                ]);
+                let string = String::from_utf8(iter.take(len as usize).cloned().collect()).ok()?;
+                Some(Command::StringLit(string))
+            }
+            8 => {
+                let num = i32::from_be_bytes([
+                    *iter.next()?,
+                    *iter.next()?,
+                    *iter.next()?,
+                    *iter.next()?,
+                ]);
+                Some(Command::I32Lit(num))
+            }
+            9 => {
+                let funcid = u16::from_be_bytes([*iter.next()?, *iter.next()?]);
+                Some(Command::FunctionCall(funcid))
+            }
+            _ => None,
+        }
+    }
+
+    fn into_u8(&self) -> Vec<u8> {
+        let mut list = Vec::new();
+        list.push(self.id());
+        match &self {
+            Command::InitializeVariable(heapid, variabletype) => {
+                let heapid = heapid.to_be_bytes();
+                list.append(&mut vec![heapid[0], heapid[1], variabletype.into_u8()])
+            }
+            Command::BeginScope => (),
+            Command::EndScope => (),
+            Command::Pop(regid) => list.push(*regid),
+            Command::Push(regid) => list.push(*regid),
+            Command::AssignVariable(heapid, regid) => {
+                let heapid = heapid.to_be_bytes();
+                list.append(&mut vec![heapid[0], heapid[1], *regid]);
+            }
+            Command::VarToReg(heapid, regid) => {
+                let heapid = heapid.to_be_bytes();
+                list.append(&mut vec![heapid[0], heapid[1], *regid]);
+            }
+            Command::StringLit(string) => {
+                let string = string.as_bytes();
+                let len = (string.len() as u32).to_be_bytes();
+                list.append(&mut vec![len[0], len[1], len[2], len[3]]);
+                list.append(&mut string.to_vec());
+            }
+            Command::I32Lit(num) => {
+                let num = num.to_be_bytes();
+                list.append(&mut vec![num[0], num[1], num[2], num[3]]);
+            }
+            Command::FunctionCall(funcid) => {
+                let funcid = funcid.to_be_bytes();
+                list.append(&mut vec![funcid[0], funcid[1]]);
+            }
+        }
+        list
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index ad1802b..0a000a7 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,11 +8,13 @@ mod file_io;
 mod parser;
 mod vm;
 
-use file_io::open_file;
-use std::path::Path;
+use file_io::{into_bytecode, open_bytecode, open_source, write_bytecode};
+use std::env;
+use std::path::{Path, PathBuf};
 
 use args::*;
 use compiler::{CompiledReid, Compiler};
+use errors::GenericError;
 use parser::Parser;
 use vm::{
     BuiltinFunctionDef, BuiltinFunctions, FunctionSignature, Value, VariableType, VirtualMachine,
@@ -33,35 +35,69 @@ fn main() {
 
     let opt: MainOpt = argh::from_env();
 
-    match opt.subcommand {
-        Subcommand::Compile(_) => {}
-        Subcommand::Run(_) => {}
-        Subcommand::CompileAndRun(c_run) => {
-            let path = Path::new(&c_run.source);
-            let compiled = compile(path, builtin_functions.signatures());
-            run(compiled, builtin_functions);
+    if let Some(run_path) = opt.run_path {
+        let compiled = open_bytecode(&run_path);
+        match compiled {
+            Ok(compiled) => run(compiled, builtin_functions),
+            Err(error) => {
+                eprintln!("{}", error);
+                std::process::exit(1);
+            }
         }
+    } else if let Some(subcommand) = opt.subcommand {
+        match subcommand {
+            Subcommand::Compile(opt) => {
+                let source = Path::new(&opt.source);
+                let output = if let Some(output) = opt.output {
+                    PathBuf::from(output)
+                } else {
+                    source.with_extension("reidc")
+                };
+                let compiled = compile(source, builtin_functions.signatures());
+                match compiled {
+                    Ok(compiled) => {
+                        let bytecode = into_bytecode(&compiled);
+                        if let Err(err) = write_bytecode(bytecode, &output) {
+                            eprintln!("{}", err);
+                            std::process::exit(1);
+                        }
+                    }
+                    Err(error) => {
+                        eprintln!("{}", error);
+                        std::process::exit(1);
+                    }
+                }
+            }
+            Subcommand::Run(opt) => {
+                let path = Path::new(&opt.source);
+                let compiled = compile(path, builtin_functions.signatures());
+                match compiled {
+                    Ok(compiled) => run(compiled, builtin_functions),
+                    Err(error) => {
+                        eprintln!("{}", error);
+                        std::process::exit(1);
+                    }
+                }
+            }
+        }
+    } else {
+        let command = env::args().collect::<Vec<String>>().join(" ");
+        eprintln!("Please try running instead:");
+        eprintln!("  {} <path>", command);
+        eprintln!("  {} help", command);
     }
 }
 
-fn compile(path: &Path, builtin: Vec<FunctionSignature>) -> CompiledReid {
-    let parsed = Parser::from(open_file(&path).ok().unwrap()).parse();
-    if let Err(error) = parsed {
-        eprintln!("Syntax error: {}", error);
-        std::process::exit(1);
-    }
-    dbg!(&parsed);
+fn compile(path: &Path, builtin: Vec<FunctionSignature>) -> Result<CompiledReid, GenericError> {
+    let parsed = Parser::from(open_source(&path)?).parse()?;
+    //dbg!(&parsed);
 
-    let compiled = Compiler::from(parsed.unwrap())
+    let compiled = Compiler::from(parsed)
         .with_builtin_functions(builtin)
-        .compile();
-    if let Err(error) = compiled {
-        eprintln!("Compilation error: {}", error);
-        std::process::exit(1);
-    }
-    dbg!(&compiled);
+        .compile()?;
+    //dbg!(&compiled);
 
-    compiled.unwrap()
+    Ok(compiled)
 }
 
 fn run(reid: CompiledReid, builtin: BuiltinFunctions) {
diff --git a/src/vm/mod.rs b/src/vm/mod.rs
index 3e79ba5..9bbc95a 100644
--- a/src/vm/mod.rs
+++ b/src/vm/mod.rs
@@ -92,7 +92,7 @@ impl VirtualMachine {
             }
             Command::Pop(regid) => {
                 if let Some(val) = self.stack.pop() {
-                    self.registry[regid] = Some(val);
+                    self.registry[regid as usize] = Some(val);
                     //dbg!("Registry popped", regid, &self.stack, &self.registry);
                     Ok(())
                 } else {
@@ -100,7 +100,7 @@ impl VirtualMachine {
                 }
             }
             Command::Push(regid) => {
-                if let Some(reg) = &self.registry[regid] {
+                if let Some(reg) = &self.registry[regid as usize] {
                     if self.stack.len() < usize::MAX {
                         self.stack.push(reg.clone());
                         //dbg!("Registry pushed", regid, &self.stack);
@@ -113,7 +113,7 @@ impl VirtualMachine {
                 }
             }
             Command::AssignVariable(heapid, regid) => {
-                if let Some(reg) = &self.registry[regid] {
+                if let Some(reg) = &self.registry[regid as usize] {
                     if let Some(var) = self.heap.get_mut(&heapid) {
                         var.try_set(Some(reg.clone()))?;
                         //dbg!("Variable assigned", heapid, regid, &self.heap);
@@ -128,7 +128,7 @@ impl VirtualMachine {
             Command::VarToReg(heapid, regid) => {
                 if let Some(var) = self.heap.get(&heapid) {
                     if let Some(val) = &var.1 {
-                        self.registry[regid] = Some(val.clone());
+                        self.registry[regid as usize] = Some(val.clone());
                         //dbg!("Variable pushed to registry", heapid, regid, &self.registry);
                         Ok(())
                     } else {
@@ -156,10 +156,10 @@ impl VirtualMachine {
                 }
             }
             Command::FunctionCall(funcid) => {
-                if self.functions.len() <= funcid {
+                if self.functions.len() <= funcid as usize {
                     Err(RuntimePanic::InvalidFuncAddress)
                 } else {
-                    match &self.functions[funcid] {
+                    match &self.functions[funcid as usize] {
                         FunctionDef::Builtin(f) => {
                             let mut params = Vec::new();
                             for _ in 0..f.signature.parameters.len() {