diff --git a/src/main.rs b/src/main.rs
index 43821cb..06dd61f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,15 +1,114 @@
 use chrono::{DateTime, Local};
-use std::{collections::HashSet, net::UdpSocket};
+use std::{
+    collections::{HashMap, HashSet},
+    net::UdpSocket,
+};
 
 const MAX_CLIENTS: usize = 10;
 const CLIENT_TIMEOUT: u32 = 300;
 
-#[derive(Hash, Eq, PartialEq, Debug)]
+#[derive(Hash, Eq, PartialEq, Debug, Clone)]
 struct Client {
     name: String,
     time: DateTime<Local>,
 }
 
+fn print_msg(msg: &[u8]) {
+    for elem in msg {
+        print!("{:08b} ", elem);
+    }
+    println!("");
+}
+
+fn strip_header(msg: &[u8]) -> Vec<u8> {
+    //print_msg(msg);
+    let mut stripped = Vec::new();
+    stripped.push(msg[1] & 3);
+    stripped.append(msg[2..].to_vec().as_mut());
+    print_msg(&stripped);
+    stripped.to_owned()
+}
+
+fn mopp(speed: u8, data: &[u8]) -> Vec<u8> {
+    let serial = 1u8;
+    let morse = HashMap::from([
+        (b'0', "-----"),
+        (b'1', ".----"),
+        (b'2', "..---"),
+        (b'3', "...--"),
+        (b'4', "....-"),
+        (b'5', "....."),
+        (b'6', "-...."),
+        (b'7', "--..."),
+        (b'8', "---.."),
+        (b'9', "----."),
+        (b'a', ".-"),
+        (b'b', "-..."),
+        (b'c', "-.-."),
+        (b'd', "-.."),
+        (b'e', "."),
+        (b'f', "..-."),
+        (b'g', "--."),
+        (b'h', "...."),
+        (b'i', ".."),
+        (b'j', ".---"),
+        (b'k', "-.-"),
+        (b'l', ".-.."),
+        (b'm', "--"),
+        (b'n', "-."),
+        (b'o', "---"),
+        (b'p', ".--."),
+        (b'q', "--.-"),
+        (b'r', ".-."),
+        (b's', "..."),
+        (b't', "-"),
+        (b'u', "..-"),
+        (b'v', "...-"),
+        (b'w', ".--"),
+        (b'x', "-..-"),
+        (b'y', "-.--"),
+        (b'z', "--.."),
+        (b'=', "-...-"),
+        (b'/', "-..-."),
+        (b'+', ".-.-."),
+        (b'-', "-....-"),
+        (b'.', ".-.-.-"),
+        (b',', "--..--"),
+        (b'?', "..--.."),
+        (b':', "---..."),
+        (b'!', "-.-.--"),
+        (b'\'', ".----."),
+    ]);
+
+    let mut m = "01".to_owned();
+    m.push_str(&format!("{:06b}", serial));
+    m.push_str(&format!("{:06b}", speed));
+
+    for &char in data {
+        if char == b' ' {
+            continue;
+        }
+
+        for b in morse.get(&char).unwrap().as_bytes() {
+            if *b == b'.' {
+                m.push_str("01");
+            } else {
+                m.push_str("10");
+            }
+        }
+
+        m.push_str("00"); // EOC
+    }
+
+    m.push_str("11"); // EOW
+
+    println!("MOPP: {1:0$}", (8 as f32 * (m.len() as f32 / 8 as f32).ceil()) as usize, m);
+
+    m.as_bytes().to_owned()
+}
+
+fn broadcast(socket: &UdpSocket, client: &Client, data: &[u8]) {}
+
 fn main() -> std::io::Result<()> {
     let socket = UdpSocket::bind("0.0.0.0:7373")?;
     socket
@@ -22,19 +121,31 @@ fn main() -> std::io::Result<()> {
         let mut buf = [0; 64];
         let (number_of_bytes, src_addr) = socket.recv_from(&mut buf).expect("Didn't receive data");
         let client_addr = src_addr.to_string();
+        let client = Client {
+            name: client_addr.clone(),
+            time: Local::now(),
+        };
+        let speed = buf[1] >> 2;
+        println!("Speed: {speed} WPM");
+
+        let data = &buf[0..number_of_bytes];
+
+        println!("Data: {:?}", strip_header(data));
+        println!("Repl: {:?}", strip_header(mopp(speed, b"hi").as_slice()));
 
         if receivers.iter().any(|x| x.name == client_addr) {
-        } else {
+            println!("Client already known.");
+        } else if strip_header(data) == strip_header(mopp(speed, b"hi").as_slice()) {
+            println!("Welcome!");
             if receivers.len() < MAX_CLIENTS {
-                let time = Local::now();
-                println!("New client: {client_addr}");
-                receivers.insert(Client {
-                    name: client_addr,
-                    time,
-                });
+                receivers.insert(client.clone());
                 // TODO: welcome
+                socket
+                    .send_to(mopp(speed, b"hi").as_slice(), &client.name)
+                    .unwrap();
             } else {
                 // TODO: reject
+                println!("Unknown client - Ignoring");
             }
         }
     }