diff --git a/src/instruments.rs b/src/instruments.rs
index 26051fb..0beb4c3 100644
--- a/src/instruments.rs
+++ b/src/instruments.rs
@@ -1,14 +1,16 @@
 use nom::{
+    branch::alt,
     bytes::complete::tag_no_case,
-    character::complete::{hex_digit1, line_ending, not_line_ending, space1},
-    combinator::{map_parser, map_res, opt},
+    character::complete::{digit1, hex_digit1, line_ending, not_line_ending, space1},
+    combinator::{map_parser, map_res, opt, success, value},
     error::{Error, ErrorKind},
-    multi::fold_many0,
-    sequence::{preceded, separated_pair, terminated},
+    multi::fold_many1,
+    sequence::{preceded, separated_pair, terminated, tuple},
     IResult,
 };
 
 #[derive(Default)]
+#[cfg_attr(test, derive(Debug, PartialEq))]
 pub struct InstrumentSet([u8; 32]);
 
 impl InstrumentSet {
@@ -20,10 +22,10 @@ impl InstrumentSet {
     }
 
     fn parse<'i>(input: &'i str) -> IResult<&'i str, Self> {
-        fold_many0(
+        fold_many1(
             terminated(
                 opt(preceded(
-                    tag_no_case("#WAVE"),
+                    tag_no_case("#WAVE "),
                     map_parser(not_line_ending, wave_numbers),
                 )),
                 line_ending,
@@ -31,7 +33,7 @@ impl InstrumentSet {
             Self::default,
             |mut set, bytes: Option<(usize, u8)>| match bytes {
                 Some((slot, sample)) => {
-                    let pos = slot - 0x20;
+                    let pos = (slot - 0x20) * 2;
                     set.0[pos] = sample;
                     set
                 }
@@ -41,18 +43,55 @@ impl InstrumentSet {
     }
 }
 
+fn hexordecimal(input: &str) -> IResult<&str, (u32, &str)> {
+    alt((
+        tuple((value(16, tag_no_case("0x")), hex_digit1)),
+        tuple((success(10), digit1)),
+    ))(input)
+}
+
 fn wave_numbers(input: &str) -> IResult<&str, (usize, u8)> {
     separated_pair(
-        map_res(hex_digit1, |s: &str| {
-            s.parse::<usize>().map_err(|_| nom::error::make_error::<&str, Error<&str>>(s, ErrorKind::HexDigit)).and_then(|n| {
-                if (0x20..0x30).contains(&n) {
-                    Ok(n)
-                } else {
-                    Err(nom::error::make_error(s, ErrorKind::MapRes))
-                }
-            })
+        map_res(hexordecimal, |(radix, s)| {
+            usize::from_str_radix(s, radix)
+                .map_err(|_| nom::error::make_error::<&str, Error<&str>>(s, ErrorKind::HexDigit))
+                .and_then(|n| {
+                    if (0x20..0x30).contains(&n) {
+                        Ok(n)
+                    } else {
+                        Err(nom::error::make_error(s, ErrorKind::MapRes))
+                    }
+                })
         }),
         space1,
-        map_res(hex_digit1, |s: &str| s.parse::<u8>()),
+        map_res(hexordecimal, |(radix, s)| {
+            u8::from_str_radix(s, radix)
+        }),
     )(input)
 }
+
+#[cfg(test)]
+mod test {
+    use super::InstrumentSet;
+
+    #[test]
+    fn parse_waves() {
+        let input = "
+#WAVE 0x20 0xA5 flute
+#WAVE 0x21 0x95 clari
+#WAVE 0x22 0x65 strings
+#WAVE 0x23 0x63 ostrings
+#WAVE 0x24 0x34 guitar
+#WAVE 0x25 0x53 fbass
+        ";
+
+        assert_eq!(
+            InstrumentSet::generate(input),
+            InstrumentSet([
+                0xa5, 0x00, 0x95, 0x00, 0x65, 0x00, 0x63, 0x00, 0x34, 0x00, 0x53, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00
+            ])
+        );
+    }
+}