diff --git a/src/headparse.rs b/src/headparse.rs
index e162603..0e5506c 100644
--- a/src/headparse.rs
+++ b/src/headparse.rs
@@ -155,7 +155,7 @@ enum AdcBlockKeys {
 #[derive(Debug, Clone)]
 pub struct SignalSpec {
     filename: String,
-    format: SignalFormat,
+    pub format: SignalFormat,
     samples_frame: Option<u64>,
     skew: Option<u64>,
     offset: Option<u64>,
@@ -431,7 +431,17 @@ impl Header {
         for signal in &self.signal_specs {
             map.entry(signal.filename.clone()).and_modify(|val: &mut u64| *val += 1 ).or_insert(1);
         }
-        return map;
+        map
+    }
+
+    pub fn signals_in_file(&self, filename: String) -> Vec<&SignalSpec> {
+        let mut buffer: Vec<&SignalSpec> = Vec::new();
+        for signal in &self.signal_specs {
+            if signal.filename == filename {
+                buffer.push(signal);
+            }
+        }
+        buffer
     }
 }
 
diff --git a/src/main.rs b/src/main.rs
index ace1a41..42f7776 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,16 +1,17 @@
-use std::{env::{self}, path::Path};
+use std::{env::{self}, os::linux::raw, path::Path, str::FromStr};
 use std::fs;
 
 pub mod headparse; // The HEAder parsing
 pub mod signal_data;
 
-use crate::{headparse::Header, signal_data::SignalData};
+use crate::{headparse::{Header, SignalSpec}, signal_data::SignalData};
 
 /// Use for handling possible formats of the WFDB data
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 enum SignalFormat {
     Format16 = 16,
     Format212 = 212,
+    Invalid = -1,
     Unimpl = 0
 }
 
@@ -64,7 +65,7 @@ fn main() -> Result<(), String>{
         }
     }
 
-    let parsed_signals = get_all_data(header, path_parent);
+    let parsed_signal_result = get_all_data(header, path_parent);
 
     println!("Hello, world!");
     Ok(())
@@ -75,14 +76,79 @@ fn help() {
     println!("\nUse in the format \"wfdb_corrosion (.hea filename)\"")
 }
 
-fn get_signal_data(spec: headparse::SignalSpec, offset: u64, data_length: usize) -> SignalData {
+fn get_signal_data(spec: &SignalSpec, offset: u64, data_length: usize, raw: &Vec<u64>) -> SignalData {
     todo!()
 }
 
-fn get_all_data(header: Header, header_root: String) -> Vec<SignalData> {
+fn get_all_data(header: Header, header_root: String) -> Result<Vec<SignalData>, String> {
     let signal_counts = header.signals_per_file();
-    for (filename, sigcount) in signal_counts {
+    for (fname, sigcount) in signal_counts {
+        let mut full = header_root.to_owned(); // Consider refactoring these to avoid this massive amount of ownership bs
+        full.push('/');
+        let fname = fname.to_owned();
 
+        full.push_str(&fname);
+        let filepath = Path::new(&full);
+        if !filepath.is_file() {
+            return Err("Error: Could not open signal .dat file. Check if the
+            header points to the right .dat file and if files are present".to_string());
+        }
+        if filepath.extension().unwrap() != "dat" {
+            println!("warn: Header file defines signal files with an extension 
+            other than .dat. 
+            Check if the header points to the right files, reading will continue
+            but correct data is not guaranteed");
+        }
+
+        // Time to actually do the work
+        let signals = header.signals_in_file(fname);
+        let format = file_signal_format_check(signals);
+        if format == SignalFormat::Invalid {
+            return Err("Error: Signals in single file use multiple formats.
+            Is your header file correctly formatted?".to_string());
+        }
+        if format == SignalFormat::Unimpl {
+            println!("Warn: Signals in single file use an unimplemented format,
+            and will be ignored");
+            continue;
+        }
+
+        let raw_bytes = fs::read(filepath).unwrap();
+
+        match format {
+            SignalFormat::Format16 => {
+                let mut buffer: u64 = 0;
+                let mut do_append = false;
+                let mut raw_converted: Vec<u64> = Vec::with_capacity(raw_bytes.len() / 2);
+
+                for byte in raw_bytes {
+                    if do_append {
+                        buffer = (buffer & 0xFF) + (byte as u64) << 8;
+                        raw_converted.push(buffer);
+                        do_append = false;
+                    } else {
+                        buffer = byte as u64;
+                        do_append = true;
+                    }
+                }
+                dbg!(raw_converted);
+            },
+            _ => {
+                panic!("Somehow reached actual file and format processing with
+                unimplemented format. Please make a bug report")
+            }
+        }
     }
     todo!()
+}
+
+fn file_signal_format_check(signals: Vec<&SignalSpec>) -> SignalFormat {
+    let first_sig = signals[0];
+    let format = first_sig.format;
+    for sig in signals {
+        if sig.format != format {
+            return SignalFormat::Invalid;
+        }
+    }
+    return format;
 }
\ No newline at end of file
diff --git a/src/signal_data.rs b/src/signal_data.rs
index 9ca1a86..93b9701 100644
--- a/src/signal_data.rs
+++ b/src/signal_data.rs
@@ -45,4 +45,9 @@ impl SignalData {
         let mut to_add: Vec<f64> = data;
         to_add.append(&mut self.values);
     }
+}
+
+pub struct SignalDataRaw {
+    name: String,
+    raw_data: Vec<u8>
 }
\ No newline at end of file